Merge branch 'master' of https://github.com/LeCoupa/awesome-cheatsheets

Merge

README.md

@@ -1,24 +1,19 @@
-![AWESOME CHEATSHEETS LOGO](_images/awesome_cheatsheets_logo@2x.png)
+![AWESOME CHEATSHEETS LOGO](_design/cover_github@2x.png)
 
-[![Awesome](https://awesome.re/badge.svg)](https://awesome.re)
+[![Awesome](https://awesome.re/badge.svg)](https://awesome.re) [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/LeCoupa/awesome-cheatsheets/blob/master/LICENSE)
 
 > 📚 Awesome cheatsheets for popular programming languages, frameworks and development tools. They include everything you should know in one single file.
 
 > ❤️ **If you like this repository, [you can click here to tweet it and make it spread](https://ctt.ec/PHba4).**
 
 
-## 🎩 Why Awesome-Cheatsheets?
+## 🤔 Why Awesome-Cheatsheets?
 
 I always make a cheatsheet when I want to improve my skills on a programming language, a framework or a development tool. [I started doing these kind of things a long time ago on Gist](https://gist.github.com/LeCoupa) To better keep track of the history and to let people contribute to them, I reorganized everything into this  single repository. Most of the content is coming from official documentations and some books I have read.
 
 Feel free to browse each cheatsheet to learn new things and to keep them at hand when you forgot about one command. They have been designed to provide a quick way to assess your knowledge and to save you time.
 
 
-## 🙌🏼 How to Contribute?
-
-You are more than welcome to contribute and build your own cheatsheet for your favorite programming language, framework or development tool. Just submit changes via pull request and I will review them before merging.
-
-
 ## 📚 Table of Contents
 
 ### 📃 Languages
@@ -52,6 +47,7 @@ You are more than welcome to contribute and build your own cheatsheet for your f
 #### Javascript
   
 * [Feathers.js](backend/feathers.js)
+* [Moleculer](backend/moleculer.js)
 * [Node.js](backend/node.js)
 </details>
 
@@ -67,6 +63,7 @@ You are more than welcome to contribute and build your own cheatsheet for your f
 
 #### Frameworks
 
+* [React.js](frontend/react.js)
 * [Vue.js](frontend/vue.js)
 </details>
 
@@ -95,24 +92,33 @@ You are more than welcome to contribute and build your own cheatsheet for your f
 #### Infrastructure
 
 * [Docker](tools/docker.sh)
+* [Kubernetes](tools/kubernetes.sh)
 * [Nanobox Boxfile](tools/nanobox_boxfile.yml)
 * [Nanobox CLI](tools/nanobox_cli.sh)
 </details>
 
 
+## 🙌🏼 How to Contribute?
+
+You are more than welcome to contribute and build your own cheatsheet for your favorite programming language, framework or development tool. Just submit changes via pull request and I will review them before merging.
+
+
 ## 🙏🏻 Contribution
 
 <table>
   <tr>
     <td align="center">
-      <a href="https://anyleads.com/" target="_blank"><img src="https://pbs.twimg.com/profile_images/838140522476761094/A4WpBe5M_400x400.jpg" height="64" /></a>
+      <a href="https://crisp.chat/?ta=oR1nEv43TM" target="_blank"><img src="https://pbs.twimg.com/profile_images/651629444944273408/r5Kd_ifq_400x400.png" height="64" /></a>
     </td>
     <td align="center">
-      <a href="https://crisp.chat/" target="_blank"><img src="https://pbs.twimg.com/profile_images/651629444944273408/r5Kd_ifq_400x400.png" height="64" /></a>
+      <a href="http://try.anyleads.com/secret" target="_blank"><img src="https://pbs.twimg.com/profile_images/838140522476761094/A4WpBe5M_400x400.jpg" height="64" /></a>
     </td>
     <td align="center">
       <a href="https://hackr.io/" target="_blank"><img src="https://d1eq8vvyuam4eq.cloudfront.net/assets/images/code-images/code-apple-touch-icon-precomposed.png" height="64" /></a>
     </td>
+    <td align="center">
+      <a href="https://learnk8s.io/" target="_blank"><img src="https://pbs.twimg.com/profile_images/925127335573114880/9yCkEIe3_400x400.jpg" height="64" /></a>
+    </td>
   </tr>
 </table>
 

backend/feathers.js

@@ -15,7 +15,7 @@
  * ******************************************************************************************* */
 
 
-```bash
+```
 # Provides the ability to initialize new application instances
 npm install @feathersjs/feathers --save
 
@@ -185,7 +185,7 @@ app.on('login', (payload, info) => {})  // sent by the authentication module and
  * ******************************************************************************************* */
 
 
-```bash
+```
 # Contains Express framework integrations
 npm install @feathersjs/express --save
 
@@ -252,7 +252,7 @@ app.configure(primus(options, callback))  // sets up the Primus transport with t
  * ******************************************************************************************* */
 
 
-```bash
+```
 # Bundles the separate Feathers client side modules into one providing the code as ES5 (compatible with modern browsers)
 # You do not have to install or load any of the other modules listed below
 npm install @feathersjs/client --save
@@ -299,7 +299,7 @@ primus(socket, options)  // initialize the Primus client using a given socket an
  * ******************************************************************************************* */
 
 
-```bash
+```
 # Assists in using JWT for authentication
 npm install @feathersjs/authentication --save
 
@@ -562,7 +562,7 @@ app.service('authentication').hooks({
  * ******************************************************************************************* */
 
 
-```bash
+```
 # [MEMORY/FILESYSTEM] In-memory database adapter
 npm install feathers-memory --save
 

backend/moleculer.js

@@ -0,0 +1,747 @@
+/* *******************************************************************************************
+ * MOLECULER MICROSERVICES FRAMEWORK - CORE CHEATSHEET
+ * http://moleculer.services/0.12/docs/
+ *
+ * Version: 0.12.x
+ * ******************************************************************************************* */
+
+
+/* *******************************************************************************************
+ * Install Moleculer
+ * ******************************************************************************************* */
+
+
+```bash
+npm i moleculer
+```
+
+
+/* *******************************************************************************************
+ * SERVICE BROKER OPTIONS
+ * ******************************************************************************************* */
+
+
+// All ServiceBroker options with default values
+const broker = new ServiceBroker({
+    namespace: "",                          // Namespace for node segmentation
+    nodeID: null,                           // NodeID. Default value is generated from hostname and PID
+
+    logger: null,                           // Logger instance.
+    logLevel: null,                         // Log level
+    logFormatter: "default",                // Log formatter. Options: "default", "simple"
+
+    transporter: null,                      // Transporter config
+    requestTimeout: 0 * 1000,               // Timeout of requests
+    requestRetry: 0,                        // Retries for requests
+    maxCallLevel: 0,                        // Maximum calling level.
+    heartbeatInterval: 5,                   // Heartbeat sending interval in seconds
+    heartbeatTimeout: 15,                   // Heartbeat timeout in seconds
+
+    disableBalancer: false,                 // Disable the built-in Moleculer balancer
+
+    registry: {                             // Service Registry options
+        strategy: "RoundRobin",             // Invocation strategy
+        strategyOptions: null,              // Strategy options
+        preferLocal: true                   // Prefer local invocations
+    },
+
+    circuitBreaker: {                       // Circuit-breaker options
+        enabled: false,                     // Enable circuit-breaker
+        maxFailures: 3,                     // Maximum failures
+        halfOpenTime: 10 * 1000,            // Half-open time interval
+        failureOnTimeout: true,             // Failure on timeouts
+        failureOnReject: true               // Failure on rejects
+    },
+
+    transit: {                              // Transit options
+        maxQueueSize: 50 * 1000             // Max items in outgoing queue
+    },
+
+    cacher: null,                           // Cacher config
+    serializer: null,                       // Serializer config
+
+    validation: true,                       // Enable params validation
+    validator: null,                        // Validator instance
+    metrics: false,                         // Enable metrics
+    metricsRate: 1,                         // Metrics rate
+    statistics: false,                      // Enable statistics
+    internalServices: true,                 // Load internal ($node) services
+
+    hotReload: false,                       // Hot-reload  services
+
+    middlewares: null,                      // List of middlewares
+
+    replCommands: null,                     // Custom REPL commands
+
+    ServiceFactory: null,                   // Custom Service factory class
+    ContextFactory: null                    // Custom Context factory class
+});
+
+
+/* *******************************************************************************************
+ * SERVICE BROKER METHODS
+ * ******************************************************************************************* */
+
+
+// Broker properties
+broker.Promise                                  // Pointer to Bluebird Promise lib
+broker.namespace                                // Namespace from options
+broker.nodeID                                   // Local NodeID
+broker.logger                                   // Logger instance
+broker.cacher                                   // Cacher instance
+broker.serializer                               // Serializer instance
+broker.validator                                // Validator instance
+
+// Broker methods
+broker.start();                                 // Start broker & all services. Returns a Promise
+broker.stop();                                  // Stop broker & all services. Returns a Promise
+broker.fatal(message, err, needExit = true);    // Fired a fatal error.
+broker.repl();                                  // Switch broker to REPL mode.
+
+broker.getLogger(module, service, version);     // Create a custom logger instance for modules
+
+broker.loadServices(folder, fileMask);          // Load all services from directory
+broker.loadService(filePath);                   // Load a service from a file
+broker.createService(schema, schemaMods);       // Create a local service from schema
+broker.destroyService(service);                 // Destroy a local service
+broker.getLocalService(name, version);          // Get a local service instance by name
+
+// Wait for services. Returns a Promise
+await broker.waitForServices(serviceNames, timeout, interval);
+await broker.waitForServices(["posts", "users"], 5000);
+await broker.waitForServices({
+    name: "posts", version: 2,
+    name: "users", version: 1
+}, 5000);
+
+broker.use(...middlewares);                     // Register middlewares
+
+broker.call(actionName, params, opts);          // Call a service
+broker.mcall(def);                              // Multiple service calls
+
+broker.emit(eventName, payload, groups);                    // Emit a balanced event
+broker.broadcast(eventName, payload, groups = null)         // Broadcast an event
+broker.broadcastLocal(eventName, payload, groups = null)    // Broadcast an event to local services
+
+broker.sendPing(nodeID);                        // Ping a remote node
+broker.MOLECULER_VERSION                        // Version number of Moleculer lib
+broker.PROTOCOL_VERSION                         // Version number of Moleculer protocol
+
+
+/* *******************************************************************************************
+ * BROKER SERVICE CALLS
+ * ******************************************************************************************* */
+
+
+// Call the "users.get" service with params
+broker.call("users.get", { id: 150 }).then(user => console.log(user));
+
+// Call with async/await
+const user = await broker.call("users.get", { id: 150});
+
+// Call with calling options
+const user = await broker.call("users.get", { id: 150}, { timeout: 5000, retryCount: 3 });
+
+// Direct call to a remote node
+const info = await broker.call("$node.services", null, { nodeID: "node-123" });
+
+// Multiple calls with array def
+const [posts, users] = await broker.mcall([
+    { action: "posts.find", params: { limit: 5, offset: 0 } },
+    { action: "users.find", params: { limit: 5, sort: "username" }, opts: { timeout: 500 } }
+]);
+
+// Multip calls with object def
+const res = await broker.mcall({
+    posts: { action: "posts.find", params: { limit: 5, offset: 0 } },
+    users: { action: "users.find", params: { limit: 5, sort: "username" }, opts: { timeout: 500 } }
+});
+console.log(res.posts, res.users);
+
+
+/* *******************************************************************************************
+ * BROKER EVENTS
+ * ******************************************************************************************* */
+
+
+// Send a balanced event with payload
+broker.emit("user.created", { user: user });
+
+// Send a balanced event only for "mail" and "payment" service (only one instance)
+broker.emit("user.created", { user: user }, ["mail", "payment"]);
+
+// Send a broadcast event (for all service instances)
+broker.broadcast("user.created", { user: user });
+
+// Send a broadcast event only for "mail" and "payment" services (all instances)
+broker.broadcast("user.created", { user: user }, ["mail", "payment"]);
+
+
+/* *******************************************************************************************
+ * NATS TRANSPORTER
+ * Requirement: `npm i nats`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "NATS"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "nats://localhost:4222"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "NATS",
+        options: {
+            url: "nats://localhost:4222",
+            user: "admin",
+            pass: "1234"
+        }
+    }
+});
+
+// With TLS (https://github.com/nats-io/node-nats#tls)
+const broker = new ServiceBroker({
+    transporter: {
+        type: "NATS",
+        options: {
+            url: "nats://localhost:4222",
+            tls: {
+                key: fs.readFileSync('./client-key.pem'),
+                cert: fs.readFileSync('./client-cert.pem'),
+                ca: [ fs.readFileSync('./ca.pem') ]
+            }
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * REDIS TRANSPORTER
+ * Requirement: `npm i ioredis`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "Redis"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "redis://redis-server:6379"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "Redis",
+        options: {
+            port: 6379,             // Redis port
+            host: 'redis-server',   // Redis host
+            family: 4,              // 4 (IPv4) or 6 (IPv6)
+            password: 'auth',       // Password
+            db: 0                   // Database index
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * MQTT TRANSPORTER
+ * Requirement: `npm i mqtt`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "MQTT"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "mqtt://mqtt-server:1883"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "MQTT",
+        options: {
+            host: "mqtt-server",
+            port: 1883,
+            username: "admin",
+            password: "1234"
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * AMQP TRANSPORTER
+ * Requirement: `npm i amqplib`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "AMQP"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "amqp://rabbitmq-server:5672"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "AMQP",
+        options: {
+            url: "amqp://user:pass@rabbitmq-server:5672",
+            eventTimeToLive: 5000,
+            prefetch: 1
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * KAFKA TRANSPORTER
+ * Requirement: `npm i kafka-node`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "Kafka"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "kafka://192.168.51.29:2181"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "kafka",
+        options: {
+            host: "192.168.51.29:2181",
+
+            // KafkaClient options. More info: https://github.com/SOHU-Co/kafka-node#clientconnectionstring-clientid-zkoptions-noackbatchoptions-ssloptions
+            client: {
+                zkOptions: undefined,
+                noAckBatchOptions: undefined,
+                sslOptions: undefined
+            },
+
+            // KafkaProducer options. More info: https://github.com/SOHU-Co/kafka-node#producerclient-options-custompartitioner
+            producer: {},
+            customPartitioner: undefined,
+
+            // ConsumerGroup options. More info: https://github.com/SOHU-Co/kafka-node#consumergroupoptions-topics
+            consumer: {
+            },
+
+            // Advanced options for `send`. More info: https://github.com/SOHU-Co/kafka-node#sendpayloads-cb
+            publish: {
+                partition: 0,
+                attributes: 0
+            }
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * NATS STREAMING TRANSPORTER
+ * Requirement: `npm i node-nats-streaming`
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "STAN"
+});
+
+// With URI
+const broker = new ServiceBroker({
+    transporter: "stan://192.168.0.120:4222"
+});
+
+// With options
+const broker = new ServiceBroker({
+    transporter: {
+        type: "STAN",
+        options: {
+            url: "stan://127.0.0.1:4222",
+            clusterID: "my-cluster"
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * TCP STREAMING TRANSPORTER
+ * No requirements
+ * ******************************************************************************************* */
+
+
+// Default options
+const broker = new ServiceBroker({
+    transporter: "TCP"
+});
+
+// With static node list
+const broker = new ServiceBroker({
+    transporter: "tcp://172.17.0.1:6000/node-1,172.17.0.2:6000/node-2"
+});
+
+const broker = new ServiceBroker({
+    nodeID: "node-1",
+    transporter: {
+        type: "TCP",
+        options: {
+            udpDiscovery: false,
+            urls: [
+                "172.17.0.1:6000/node-1",
+                "172.17.0.2:6000/node-2",
+                "172.17.0.3:6000/node-3"
+            ]
+        }
+    }
+});
+
+// With full options
+const broker = new ServiceBroker({
+    logger: true,
+    transporter: {
+        type: "TCP",
+        options: {
+            // Enable UDP discovery
+            udpDiscovery: true,
+            // Reusing UDP server socket
+            udpReuseAddr: true,
+
+            // UDP port
+            udpPort: 4445,
+            // UDP bind address
+            udpBindAddress: null,
+            // UDP sending period
+            udpPeriod: 5,
+
+            // Multicast address.
+            udpMulticast: "239.0.0.0",
+            // Multicast TTL setting
+            udpMulticastTTL: 1,
+
+            // Send broadcast
+            udpBroadcast: false,
+
+            // TCP server port. Null or 0 means random port
+            port: null,
+            // Static remote nodes address list (when UDP discovery is not available)
+            urls: null,
+            // Use hostname as preffered connection address
+            useHostname: true,
+
+            // Gossip sending period in seconds
+            gossipPeriod: 2,
+            // Maximum enabled outgoing connections. If reach, close the old connections
+            maxConnections: 32,
+            // Maximum TCP packet size
+            maxPacketSize: 1 * 1024 * 1024
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * CACHERS
+ * http://moleculer.services/docs/cachers.html
+ * ******************************************************************************************* */
+
+
+// Memory cacher
+const broker = new ServiceBroker({
+    cacher: "Memory"
+});
+// or
+const broker = new ServiceBroker({
+    cacher: true
+});
+
+// Memory cacher with options
+const broker = new ServiceBroker({
+    cacher: {
+        type: "Memory",
+        options: {
+            ttl: 30
+        }
+    }
+});
+
+// Redis cacher
+const broker = new ServiceBroker({
+    cacher: "Redis"
+});
+
+// Redis cacher with URI
+const broker = new ServiceBroker({
+    cacher: "redis://redis-server:6379"
+});
+
+// Redis cacher with options
+const broker = new ServiceBroker({
+    cacher: {
+        type: "Redis",
+        options: {
+            prefix: "MOL",
+            redis: {
+                host: "redis",
+                port: 6379,
+                password: "1234",
+                db: 0
+            }
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * Manual caching
+ * ******************************************************************************************* */
+
+
+// Save to cache
+broker.cacher.set("mykey.a", { a: 5 });
+
+// Get from cache
+const obj = await broker.cacher.get("mykey.a");
+
+// Remove entry from cache
+broker.cacher.del("mykey.a");
+
+// Clean all 'mykey' entries
+broker.cacher.clean("mykey.*");
+
+// Clean all entries
+broker.cacher.clean();
+
+
+/* *******************************************************************************************
+ * SERIALIZER
+ * http://moleculer.services/docs/serializers.html
+ * ******************************************************************************************* */
+
+
+// JSON serializer (default)
+const broker = new ServiceBroker({
+    serializer: "JSON"
+});
+
+// Avro serializer (need `npm i avsc`)
+const broker = new ServiceBroker({
+    serializer: "Avro"
+});
+
+// Protocol Buffer serializer (need `npm i protobufjs`)
+const broker = new ServiceBroker({
+    serializer: "ProtoBuf"
+});
+
+// MsgPack serializer (need `npm i msgpack5`)
+const broker = new ServiceBroker({
+    serializer: "MsgPack"
+});
+
+
+/* *******************************************************************************************
+ * STRATEGY
+ * ******************************************************************************************* */
+
+
+// Round-robin strategy (default)
+const broker = new ServiceBroker({
+    registry: {
+        strategy: "RoundRobin"
+    }
+});
+
+// Random strategy
+const broker = new ServiceBroker({
+    registry: {
+        strategy: "Random"
+    }
+});
+
+// CPU usage-based strategy
+const broker = new ServiceBroker({
+    registry: {
+        strategy: "CpuUsageStrategy"
+    }
+});
+
+// CPU usage-based strategy with options
+const broker = new ServiceBroker({
+    registry: {
+        strategy: "CpuUsageStrategy",
+        strategyOptions: {
+            sampleCount: 3,
+            lowCpuUsage: 10
+        }
+    }
+});
+
+
+/* *******************************************************************************************
+ * LOGGER
+ * http://moleculer.services/docs/logger.html
+ * ******************************************************************************************* */
+
+
+// Logger methods
+broker.logger.fatal();
+broker.logger.error();
+broker.logger.warn();
+broker.logger.info();
+broker.logger.debug();
+broker.logger.trace();
+
+// Custom log formatter
+const broker = new ServiceBroker({
+    logger: console,
+    logFormatter(level, args, bindings) {
+        return level.toUpperCase() + " " + bindings.nodeID + ": " + args.join(" ");
+    }
+});
+
+// External Pino logger
+const pino = require("pino")({ level: "info" });
+const broker = new ServiceBroker({
+    logger: bindings => pino.child(bindings)
+});
+
+// External Bunyan logger
+const logger = require("bunyan").createLogger({ name: "moleculer", level: "info" });
+const broker = new ServiceBroker({
+    logger: bindings => logger.child(bindings)
+});
+
+
+/* *******************************************************************************************
+ * SERVICE SCHEMA
+ * ******************************************************************************************* */
+
+
+module.exports = {
+    // Name
+    name: "greeter",
+    // Version
+    version: 2,
+
+    // Settings
+    settings: {},
+    // Metadata
+    metadata: {},
+    // Dependencies
+    dependencies: [],
+
+    // Actions
+    actions: {
+        // Shorthand actions
+        hello() {
+            // Call a method
+            this.doSomething();
+
+            return "Hello Moleculer";
+        },
+
+        // With properties
+        welcome: {
+            // Cache options
+            cache: {
+                keys: ["name"]
+            },
+            // Validation options
+            params: {
+                name: "string"
+            },
+            // Action handler
+            handler(ctx) {
+                return `Welcome, ${ctx.params.name}`;
+            }
+        }
+    },
+
+    events: {
+        "user.created"(payload, sender) {
+
+        }
+    },
+
+    // Service methods
+    methods: {
+        doSomething() {}
+    },
+
+    // Lifecycle event handlers
+    created() {
+        console.log("Service created");
+    },
+
+    started() {
+        console.log("Service started");
+        return Promise.resolve();
+    },
+
+    stopped() {
+        console.log("Service stopped");
+        return Promise.resolve();
+    }
+};
+
+
+/* *******************************************************************************************
+ * SERVICE
+ * ******************************************************************************************* */
+
+
+this.name               // Name of service
+this.version            // Version of service
+this.settings           // Settings of service
+this.schema             // Schema definition of service
+this.broker             // Broker instance
+this.Promise            // Class of Promise (Bluebird)
+this.logger             // Logger instance
+this.actions            // Actions of service.
+this.waitForServices    // Pointer to ‘broker.waitForServices’ method
+
+
+/* *******************************************************************************************
+ * CONTEXT
+ * ******************************************************************************************* */
+
+ 
+ctx.id                  // Context ID
+ctx.broker              // Broker instance
+ctx.action              // Action definition
+ctx.nodeID              // Node ID
+ctx.requestID           // Request ID
+ctx.parentID            // ID of parent context (in case of sub-calls).
+ctx.params              // Request params
+ctx.meta                // Request metadata
+ctx.callerNodeID        // Caller Node ID if it is requested from a remote node.
+ctx.level               // Request level (in case of sub-calls). The first level is 1.
+
+// Make a sub-call
+ctx.call(actionName, params, callingOptions)
+
+// Emit an event
+ctx.emit(eventName, payload, groups);

frontend/angularjs.js

@@ -0,0 +1,434 @@
+/* *******************************************************************************************
+ * ANGULARJS CHEATSHEET
+ * API DOCUMENTATION: https://docs.angularjs.org/api
+ * DEVELOPER GUIDE: https://docs.angularjs.org/guide
+ * ERROR REFERENCE: https://docs.angularjs.org/error
+ * ******************************************************************************************* */
+
+
+/* *******************************************************************************************
+ * TIPS & TRICKS
+ * ******************************************************************************************* */
+
+
+// You can retrieve a scope for any DOM element by using:
+angular.element(aDomElement).scope()
+
+// An object that contains information about the current AngularJS version.
+// This object has the following properties: full, major, minor, dot, codeName
+angular.version
+
+
+/* *******************************************************************************************
+ * CSS CLASS USED BY ANGULAR
+ * ******************************************************************************************* */
+
+
+// AngularJS applies this class to any element for which a new scope is defined.
+ng-scope
+
+// AngularJS applies this class to any element for which a new isolate scope is defined.
+ng-isolate-scope
+
+// AngularJS applies this class to any element that is attached to a data binding, via ng-bind or {{}} curly braces, for example.
+ng-binding
+
+// AngularJS applies this class to a form control widget element if that element's input does not pass validation.
+ng-invalid, ng-valid
+
+// AngularJS ngModel directive applies ng-pristine class to a new form control widget which did not have user interaction.
+// Once the user interacts with the form control, the class is changed to ng-dirty.
+ng-pristine, ng-dirty
+
+// AngularJS ngModel directive applies ng-untouched class to a new form control widget which has not been blurred.
+// Once the user blurs the form control, the class is changed to ng-touched.
+ng-touched, ng-untouched
+
+
+/* *******************************************************************************************
+ * NG MODULE > FUNCTIONS
+ * ******************************************************************************************* */
+
+
+// Returns a function which calls function fn bound to self (self becomes the this for fn).
+// You can supply optional args that are prebound to the function.
+// This feature is also known as partial application, as distinguished from function currying.
+angular.bind(self, fn, args)
+
+// Use this function to manually start up AngularJS application.
+angular.bootstrap(element, [modules], [config])
+
+// Creates a deep copy of source, which should be an object or an array.
+angular.copy(source, [destination])
+
+// Wraps a raw DOM element or HTML string as a jQuery element.
+angular.element(element)
+
+// Determines if two objects or two values are equivalent.
+// Supports value types, regular expressions, arrays and objects.
+angular.equals(o1, o2)
+
+// Configure several aspects of error handling in AngularJS if used as a setter or return the current configuration if used as a getter.
+angular.errorHandlingConfig([config])
+
+// Extends the destination object dst by copying own enumerable properties from the src object(s) to dst.
+// You can specify multiple src objects.
+angular.extend(dst, src)
+
+// Invokes the iterator function once for each item in obj collection, which can be either an object or an array.
+angular.forEach(obj, iterator, [context])
+
+// Deserializes a JSON string.
+angular.fromJson(json)
+
+// A function that returns its first argument.
+// This function is useful when writing code in the functional style.
+angular.identity(value)
+
+// Creates an injector object that can be used for retrieving services as well as for dependency injection.
+angular.injector(modules, [strictDi])
+
+// Determines if a reference is an Array.
+angular.isArray(value)
+
+// Determines if a value is a date.
+angular.isDate(value)
+
+// Determines if a reference is defined.
+angular.isDefined(value)
+
+// Determines if a reference is a DOM element (or wrapped jQuery element).
+angular.isElement(value)
+
+// Determines if a reference is a Function.
+angular.isFunction(value)
+
+// Determines if a reference is a Number.
+angular.isNumber(value)
+
+// Determines if a reference is an Object. Unlike typeof in JavaScript, nulls are not considered to be objects.
+angular.isObject(value)
+
+// Determines if a reference is a String.
+angular.isString(value)
+
+// Determines if a reference is undefined.
+angular.isUndefined(value)
+
+// The angular.module is a global place for creating, registering and retrieving AngularJS modules.
+// All modules (AngularJS core or 3rd party) that should be available to an application must be registered using this mechanism.
+// Passing one argument retrieves an existing angular.Module, whereas passing more than one argument creates a new angular.Module
+angular.module(name, [requires], [configFn])
+
+// A function that performs no operations.
+// This function can be useful when writing code in the functional style.
+angular.noop()
+
+// Use this function to reload the current application with debug information turned on.
+// This takes precedence over a call to $compileProvider.debugInfoEnabled(false).
+angular.reloadWithDebugInfo()
+
+// Serializes input into a JSON-formatted string.
+// Properties with leading $$ characters will be stripped since AngularJS uses this notation internally.
+angular.toJson(obj, pretty)
+
+
+/* *******************************************************************************************
+ * NG MODULE > DIRECTIVES
+ * ******************************************************************************************* */
+
+
+// Use this directive to auto-bootstrap an AngularJS application.
+// Only one AngularJS application can be auto-bootstrapped per HTML document.
+// You can specify an AngularJS module to be used as the root module for the application.
+'ng-app'
+
+// The ngBind attribute tells AngularJS to replace the text content of the specified HTML element with
+// the value of a given expression, and to update the text content when the value of that expression changes.
+'ng-bind'
+
+// Evaluates the expression and inserts the resulting HTML into the element in a secure way.
+'ng-bind-html'
+
+// The ngBindTemplate directive specifies that the element text content should be replaced with
+// the interpolation of the template in the ngBindTemplate attribute.
+'ng-bind-template'
+
+// Specify custom behavior on blur event.
+'ng-blur'
+
+// Evaluate the given expression when the user changes the input.
+'ng-change'
+
+// Sets the checked attribute on the element, if the expression inside ngChecked is truthy.
+'ng-checked'
+
+// The ngClass directive allows you to dynamically set CSS classes on an HTML element by databinding
+// an expression that represents all classes to be added.
+'ng-class'
+
+// The ngClassOdd and ngClassEven directives work exactly as ngClass, except they work in
+// conjunction with ngRepeat and take effect only on odd (even) rows.
+'ng-class-even'
+
+// The ngClassOdd and ngClassEven directives work exactly as ngClass, except they work in
+// conjunction with ngRepeat and take effect only on odd (even) rows.
+'ng-class-odd'
+
+// The ngClick directive allows you to specify custom behavior when an element is clicked.
+'ng-click'
+
+// The ngCloak directive is used to prevent the AngularJS html template from being briefly displayed
+// by the browser in its raw (uncompiled) form while your application is loading.
+'ng-cloak'
+
+// The ngController directive attaches a controller class to the view.
+'ng-controller'
+
+// Specify custom behavior on copy event.
+'ng-copy'
+
+// Specify custom behavior on cut event.
+'ng-cut'
+
+// Allows you to specify custom behavior on a dblclick event.
+'ng-dblclick'
+
+// This directive sets the disabled attribute on the element (typically a form control, e.g. input, button, select etc.)
+// if the expression inside ngDisabled evaluates to truthy.
+'ng-disabled'
+
+// Specify custom behavior on focus event.
+'ng-focus'
+
+// Nestable alias of form directive. HTML does not allow nesting of form elements.
+// It is useful to nest forms, for example if the validity of a sub-group of controls needs to be determined.
+'ng-form'
+
+// Shows or hides the given HTML element based on the expression provided to the ngHide attribute.
+'ng-hide'
+
+// Executes the expression and replaces with the right href link
+'ng-href'
+
+// Removes or recreates a portion of the DOM tree based on an {expression}.
+'ng-if'
+
+// Fetches, compiles and includes an external HTML fragment.
+'ng-include'
+
+// Allows you to evaluate an expression in the current scope.
+'ng-init'
+
+// Force the angular.element library.
+// This should be used to force either jqLite by leaving ng-jq blank or setting the name of the jquery variable under window (eg. jQuery).
+'ng-jq'
+
+// Specify custom behavior on keydown event.
+'ng-keydown'
+
+// Specify custom behavior on keypress event.
+'ng-keypress'
+
+// Specify custom behavior on keyup event.
+'ng-keyup'
+
+// Text input that converts between a delimited string and an array of strings.
+'ng-list'
+
+// Adds the maxlength validator to ngModel.
+'ng-maxlength'
+
+// Adds the minlength validator to ngModel.
+'ng-minlength'
+
+// The ngModel directive binds an input,select, textarea (or custom form control) to a property on the scope using NgModelController,
+// which is created and exposed by this directive.
+'ng-model'
+
+// Modify the behaviour of ngModel directives within your application.
+// You can specify an ngModelOptions directive on any element.
+// All ngModel directives will use the options of their nearest ngModelOptions ancestor.
+'ng-model-options'
+
+// Allows you to specify custom behavior on mousedown event.
+'ng-mousedown'
+
+// Specify custom behavior on mouseenter event.
+'ng-mouseenter'
+
+// Specify custom behavior on mouseleave event.
+'ng-mouseleave'
+
+// Specify custom behavior on mousemove event.
+'ng-mousemove'
+
+// Specify custom behavior on mouseover event.
+'ng-mouseover'
+
+// Specify custom behavior on mouseup event.
+'ng-mouseup'
+
+// Tells AngularJS not to compile or bind the contents of the current DOM element,
+// including directives on the element itself that have a lower priority than ngNonBindable.
+'ng-non-bindable'
+
+// Sets the open attribute on the element, if the expression inside ngOpen is truthy.
+'ng-open'
+
+// The ngOptions attribute can be used to dynamically generate a list of <option> elements for the <select>
+// element using the array or object obtained by evaluating the ngOptions comprehension expression.
+'ng-options'
+
+// Specify custom behavior on paste event.
+'ng-paste'
+
+// ngPattern adds the pattern validator to ngModel.
+// It is most often used for text-based input controls, but can also be applied to custom text-based controls.
+'ng-pattern'
+
+// Displays messages according to en-US localization rules.
+'ng-pluralize'
+
+// Sets the readonly attribute on the element, if the expression inside ngReadonly is truthy
+'ng-readonly'
+
+// Instantiates a template once per item from a collection
+// Special properties are exposed on the local scope of each template instance, including:
+// $index, $first, $middle, $last, $even, $odd
+'ng-repeat'
+
+// ngRequired adds the required validator to ngModel.
+// It is most often used for input and select controls, but can also be applied to custom controls.
+'ng-required'
+
+// Sets the selected attribute on the element, if the expression inside ngSelected is truthy.
+'ng-selected'
+
+// Shows or hides the given HTML element based on the expression provided to the ngShow attribute.
+'ng-show'
+
+// Using AngularJS markup like {{hash}} in a src attribute doesn't work right:
+// The browser will fetch from the URL with the literal text {{hash}} until AngularJS
+// replaces the expression inside {{hash}}. The ngSrc directive solves this problem.
+'ng-src'
+
+// Using AngularJS markup like {{hash}} in a srcset attribute doesn't work right:
+// The browser will fetch from the URL with the literal text {{hash}} until AngularJS
+// replaces the expression inside {{hash}}. The ngSrcset directive solves this problem.
+'ng-srcset'
+
+// Allows you to set CSS style on an HTML element conditionally.
+'ng-style'
+
+// Enables binding AngularJS expressions to onsubmit events.
+'ng-submit'
+
+// Used to conditionally swap DOM structure on your template based on a scope expression.
+'ng-switch'
+
+// Marks the insertion point for the transcluded DOM of the nearest parent directive that uses transclusion.
+'ng-transclude'
+
+// Binds the given expression to the value of the element.
+// It is mainly used on input[radio] and option elements, so that when the element is selected,
+// the ngModel of that element (or its select parent element) is set to the bound value.
+'ng-value'
+
+
+/* *******************************************************************************************
+ * NG MODULE > TYPE
+ * ******************************************************************************************* */
+
+
+// A cache object used to store and retrieve data, primarily used by $templateRequest
+// and the script directive to cache templates and other data.
+$cacheFactory.Cache
+
+// Don't forget the cache
+
+// A shared object between directive compile / linking functions which contains normalized
+// DOM element attributes. The values reflect current binding state {{ }}.
+$compile.directive.Attributes
+
+// Converts an attribute name (e.g. dash/colon/underscore-delimited string, optionally prefixed with x- or data-)
+// to its normalized, camelCase form.
+$compile.directive.Attributes.$normalize(name)
+
+// Adds the CSS class value specified by the classVal parameter to the element.
+// If animations are enabled then an animation will be triggered for the class addition.
+$compile.directive.Attributes.$addClass(classVal)
+
+// Removes the CSS class value specified by the classVal parameter from the element.
+// If animations are enabled then an animation will be triggered for the class removal.
+$compile.directive.Attributes.$removeClass(classVal)
+
+// Adds and removes the appropriate CSS class values to the element based on the difference
+// between the new and old CSS class values (specified as newClasses and oldClasses).
+$compile.directive.Attributes.$updateClass(newClasses, oldClasses)
+
+// Observes an interpolated attribute.
+$compile.directive.Attributes.$observe(key, fn)
+
+// Set DOM element attribute value.
+$compile.directive.Attributes.$set(name, value)
+
+// A map of DOM element attribute names to the normalized name.
+// This is needed to do reverse lookup from normalized name back to actual name.
+$compile.directive.Attributes.$attr
+
+// A root scope can be retrieved using the $rootScope key from the $injector.
+$rootScope.Scope([providers], [instanceCache])
+
+
+/* *******************************************************************************************
+ * NG MODULE > FILTERS
+ * ******************************************************************************************* */
+
+
+// Formats a number as a currency (ie $1,234.56).
+// When no currency symbol is provided, default symbol for current locale is used.
+{{ currency_expression | currency : symbol : fractionSize}}
+$filter('currency')(amount, symbol, fractionSize)
+
+// Formats date to a string based on the requested format.
+{{ date_expression | date : format : timezone}}
+$filter('date')(date, format, timezone)
+
+// Selects a subset of items from array and returns it as a new array.
+{{ filter_expression | filter : expression : comparator : anyPropertyKey}}
+$filter('filter')(array, expression, comparator, anyPropertyKey)
+
+// Allows you to convert a JavaScript object into JSON string.
+// This filter is mostly useful for debugging.
+// When using the double curly notation the binding is automatically converted to JSON.
+{{ json_expression | json : spacing}}
+$filter('json')(object, spacing)
+
+// Creates a new array or string containing only a specified number of elements.
+// The elements are taken from either the beginning or the end of the source array,
+// string or number, as specified by the value and sign (positive or negative) of limit.
+// Other array-like objects are also supported (e.g. array subclasses, NodeLists, jqLite/jQuery collections etc).
+// If a number is used as input, it is converted to a string.
+{{ limitTo_expression | limitTo : limit : begin}}
+$filter('limitTo')(input, limit, begin)
+
+// Converts string to lowercase.
+{{ lowercase_expression | lowercase}}
+$filter('lowercase')()
+
+// Formats a number as text.
+// If the input is null or undefined, it will just be returned.
+// If the input is infinite (Infinity or -Infinity), the Infinity symbol '∞' or '-∞' is returned, respectively.
+// If the input is not a number an empty string is returned.
+{{ number_expression | number : fractionSize}}
+$filter('number')(number, fractionSize)
+
+// Returns an array containing the items from the specified collection,
+// ordered by a comparator function based on the values computed using the expression predicate.
+{{ orderBy_expression | orderBy : expression : reverse : comparator}}
+$filter('orderBy')(collection, expression, reverse, comparator)
+
+// Converts string to uppercase.
+{{ uppercase_expression | uppercase}}
+$filter('uppercase')()

frontend/react.js

@@ -0,0 +1,339 @@
+/* *******************************************************************************************
+ * REACT.JS CHEATSHEET
+ * DOCUMENTATION: https://reactjs.org/docs/
+ * FILE STRUCTURE: https://reactjs.org/docs/faq-structure.html
+ * ******************************************************************************************* */
+
+
+```
+npm install --save react       // declarative and flexible JavaScript library for building UI
+npm install --save react-dom   // serves as the entry point of the DOM-related rendering paths
+npm install --save prop-types  // runtime type checking for React props and similar objects
+```
+
+// notes: don't forget the command lines
+
+
+/* *******************************************************************************************
+ * REACT
+ * https://reactjs.org/docs/react-api.html
+ * ******************************************************************************************* */
+
+
+// Create and return a new React element of the given type.
+// Code written with JSX will be converted to use React.createElement().
+// You will not typically invoke React.createElement() directly if you are using JSX.
+React.createElement(
+  type,
+  [props],
+  [...children]
+)
+
+// Clone and return a new React element using element as the starting point.
+// The resulting element will have the original element’s props with the new props merged in shallowly.
+React.cloneElement(
+  element,
+  [props],
+  [...children]
+)
+
+// Verifies the object is a React element. Returns true or false.
+React.isValidElement(object)
+
+React.Children  // provides utilities for dealing with the this.props.children opaque data structure.
+
+// Invokes a function on every immediate child contained within children with this set to thisArg.
+React.Children.map(children, function[(thisArg)])
+
+// Like React.Children.map() but does not return an array.
+React.Children.forEach(children, function[(thisArg)])
+
+// Returns the total number of components in children,
+// equal to the number of times that a callback passed to map or forEach would be invoked.
+React.Children.count(children)
+
+// Verifies that children has only one child (a React element) and returns it.
+// Otherwise this method throws an error.
+React.Children.only(children)
+
+// Returns the children opaque data structure as a flat array with keys assigned to each child.
+// Useful if you want to manipulate collections of children in your render methods,
+// especially if you want to reorder or slice this.props.children before passing it down.
+React.Children.toArray(children)
+
+// The React.Fragment component lets you return multiple elements in a render() method without creating an additional DOM element
+// You can also use it with the shorthand <></> syntax.
+React.Fragment
+
+
+/* *******************************************************************************************
+ * REACT.COMPONENT
+ * React.Component is an abstract base class, so it rarely makes sense to refer to React.Component
+ * directly. Instead, you will typically subclass it, and define at least a render() method.
+ * https://reactjs.org/docs/react-component.html
+ * ******************************************************************************************* */
+
+
+class Component extends React.Component {
+  // Will be called before it is mounted
+  constructor(props) {
+    // Call this method before any other statement
+    // or this.props will be undefined in the constructor
+    super(props);
+
+    // The constructor is also often used to bind event handlers to the class instance.
+    // Binding makes sure the method has access to component attributes like this.props and this.state
+    this.method = this.method.bind(this);
+
+    // The constructor is the right place to initialize state. 
+    this.state = {
+      active: true,
+
+      // In rare cases, it’s okay to initialize state based on props.
+      // This effectively “forks” the props and sets the state with the initial props.
+      // If you “fork” props by using them for state, you might also want to implement componentWillReceiveProps(nextProps)
+      // to keep the state up-to-date with them. But lifting state up is often easier and less bug-prone.
+      color: props.initialColor
+    };
+  }
+
+  // Enqueues changes to the component state and
+  // tells React that this component and its children need to be re-rendered with the updated state.
+  // setState() does not always immediately update the component. It may batch or defer the update until later.
+  // This makes reading this.state right after calling setState() a potential pitfall.
+  // Instead, use componentDidUpdate or a setState callback.
+  // You may optionally pass an object as the first argument to setState() instead of a function.
+  setState(updater[, callback]) { }
+
+  // Invoked just before mounting occurs (before render())
+  // This is the only lifecycle hook called on server rendering.
+  componentWillMount() { }
+
+  // Invoked immediately after a component is mounted.
+  // Initialization that requires DOM nodes should go here.
+  // If you need to load data from a remote endpoint, this is a good place to instantiate the network request.
+  // This method is a good place to set up any subscriptions. If you do that, don’t forget to unsubscribe in componentWillUnmount().
+  componentDidMount() { }
+
+  // Invoked before a mounted component receives new props.
+  // If you need to update the state in response to prop changes (for example, to reset it),
+  // you may compare this.props and nextProps and perform state transitions using this.setState() in this method.
+  componentWillReceiveProps(nextProps) { }
+
+  // Let React know if a component’s output is not affected by the current change in state or props.
+  // The default behavior is to re-render on every state change, and in the vast majority of cases you should rely on the default behavior.
+  // shouldComponentUpdate() is invoked before rendering when new props or state are being received. Defaults to true.
+  // This method is not called for the initial render or when forceUpdate() is used.
+  // Returning false does not prevent child components from re-rendering when their state changes.
+  shouldComponentUpdate(nextProps, nextState) { }
+
+  // Invoked just before rendering when new props or state are being received.
+  // Use this as an opportunity to perform preparation before an update occurs. This method is not called for the initial render.
+  // Note that you cannot call this.setState() here; nor should you do anything else
+  // (e.g. dispatch a Redux action) that would trigger an update to a React component before componentWillUpdate() returns.
+  // If you need to update state in response to props changes, use componentWillReceiveProps() instead.
+  componentWillUpdate(nextProps, nextState) { }
+
+  // Invoked immediately after updating occurs. This method is not called for the initial render.
+  // Use this as an opportunity to operate on the DOM when the component has been updated.
+  // This is also a good place to do network requests as long as you compare the current props to previous props (e.g. a network request may not be necessary if the props have not changed).
+  componentDidUpdate(prevProps, prevState) { }
+
+  // Invoked immediately before a component is unmounted and destroyed.
+  // Perform any necessary cleanup in this method, such as invalidating timers, canceling network requests,
+  // or cleaning up any subscriptions that were created in componentDidMount().
+  componentWillUnmount() { }
+
+  // Error boundaries are React components that catch JavaScript errors anywhere in their child component tree,
+  // log those errors, and display a fallback UI instead of the component tree that crashed.
+  // Error boundaries catch errors during rendering, in lifecycle methods, and in constructors of the whole tree below them.
+  componentDidCatch() { }
+
+  // This method is required.
+  // It should be pure, meaning that it does not modify component state,
+  // it returns the same result each time it’s invoked, and
+  // it does not directly interact with the browser (use lifecycle methods for this)
+  // It must return one of the following types: react elements, string and numbers, portals, null or booleans.
+  render() {
+    // Contains the props that were defined by the caller of this component.
+    console.log(this.props);
+
+    // Contains data specific to this component that may change over time.
+    // The state is user-defined, and it should be a plain JavaScript object.
+    // If you don’t use it in render(), it shouldn’t be in the state.
+    // For example, you can put timer IDs directly on the instance.
+    // Never mutate this.state directly, as calling setState() afterwards may replace the mutation you made.
+    // Treat this.state as if it were immutable.
+    console.log(this.state);
+
+    return (
+      <div>
+        {/* Comment goes here */}
+        Hello, {this.props.name}!
+      </div>
+    );
+  }
+}
+
+// Can be defined as a property on the component class itself, to set the default props for the class.
+// This is used for undefined props, but not for null props.
+Component.defaultProps = {
+  color: 'blue'
+};
+
+component = new Component();
+
+// By default, when your component’s state or props change, your component will re-render.
+// If your render() method depends on some other data, you can tell React that the component needs re-rendering by calling forceUpdate().
+// Normally you should try to avoid all uses of forceUpdate() and only read from this.props and this.state in render().
+component.forceUpdate(callback)
+
+
+/* *******************************************************************************************
+ * REACT.DOM
+ * The react-dom package provides DOM-specific methods that can be used at the top level of
+ * your app and as an escape hatch to get outside of the React model if you need to.
+ * Most of your components should not need to use this module.
+ * https://reactjs.org/docs/react-dom.html
+ * ******************************************************************************************* */
+
+
+// Render a React element into the DOM in the supplied container and return a reference
+// to the component (or returns null for stateless components).
+ReactDOM.render(element, container[, callback])
+
+// Same as render(), but is used to hydrate a container whose HTML contents were rendered
+// by ReactDOMServer. React will attempt to attach event listeners to the existing markup.
+ReactDOM.hydrate(element, container[, callback])
+
+// Remove a mounted React component from the DOM and clean up its event handlers and state.
+// If no component was mounted in the container, calling this function does nothing.
+// Returns true if a component was unmounted and false if there was no component to unmount.
+ReactDOM.unmountComponentAtNode(container)
+
+// If this component has been mounted into the DOM, this returns the corresponding native browser
+// DOM element. This method is useful for reading values out of the DOM, such as form field values
+// and performing DOM measurements. In most cases, you can attach a ref to the DOM node and avoid
+// using findDOMNode at all.
+ReactDOM.findDOMNode(component)
+
+// Creates a portal. Portals provide a way to render children into a DOM node that exists outside
+// the hierarchy of the DOM component.
+ReactDOM.createPortal(child, container)
+
+
+/* *******************************************************************************************
+ * REACTDOMSERVER
+ * The ReactDOMServer object enables you to render components to static markup.
+ * https://reactjs.org/docs/react-dom.html
+ * ******************************************************************************************* */
+
+
+// Render a React element to its initial HTML. React will return an HTML string.
+// You can use this method to generate HTML on the server and send the markup down on the initial
+// request for faster page loads and to allow search engines to crawl your pages for SEO purposes.
+ReactDOMServer.renderToString(element)
+
+// Similar to renderToString, except this doesn’t create extra DOM attributes that React uses
+// internally, such as data-reactroot. This is useful if you want to use React as a simple static
+// page generator, as stripping away the extra attributes can save some bytes.
+ReactDOMServer.renderToStaticMarkup(element)
+
+// Render a React element to its initial HTML. Returns a Readable stream that outputs an HTML string.
+// The HTML output by this stream is exactly equal to what ReactDOMServer.renderToString would return.
+// You can use this method to generate HTML on the server and send the markup down on the initial
+// request for faster page loads and to allow search engines to crawl your pages for SEO purposes.
+ReactDOMServer.renderToNodeStream(element)
+
+// Similar to renderToNodeStream, except this doesn’t create extra DOM attributes that React uses
+// internally, such as data-reactroot. This is useful if you want to use React as a simple static
+// page generator, as stripping away the extra attributes can save some bytes.
+ReactDOMServer.renderToStaticNodeStream(element)
+
+
+/* *******************************************************************************************
+ * TYPECHECKING WITH PROPTYPES
+ * https://reactjs.org/docs/typechecking-with-proptypes.html
+ * ******************************************************************************************* */
+
+
+import PropTypes from 'prop-types';
+
+MyComponent.propTypes = {
+  // You can declare that a prop is a specific JS type. By default, these
+  // are all optional.
+  optionalArray: PropTypes.array,
+  optionalBool: PropTypes.bool,
+  optionalFunc: PropTypes.func,
+  optionalNumber: PropTypes.number,
+  optionalObject: PropTypes.object,
+  optionalString: PropTypes.string,
+  optionalSymbol: PropTypes.symbol,
+
+  // Anything that can be rendered: numbers, strings, elements or an array
+  // (or fragment) containing these types.
+  optionalNode: PropTypes.node,
+
+  // A React element.
+  optionalElement: PropTypes.element,
+
+  // You can also declare that a prop is an instance of a class. This uses
+  // JS's instanceof operator.
+  optionalMessage: PropTypes.instanceOf(Message),
+
+  // You can ensure that your prop is limited to specific values by treating
+  // it as an enum.
+  optionalEnum: PropTypes.oneOf(['News', 'Photos']),
+
+  // An object that could be one of many types
+  optionalUnion: PropTypes.oneOfType([
+    PropTypes.string,
+    PropTypes.number,
+    PropTypes.instanceOf(Message)
+  ]),
+
+  // An array of a certain type
+  optionalArrayOf: PropTypes.arrayOf(PropTypes.number),
+
+  // An object with property values of a certain type
+  optionalObjectOf: PropTypes.objectOf(PropTypes.number),
+
+  // An object taking on a particular shape
+  optionalObjectWithShape: PropTypes.shape({
+    color: PropTypes.string,
+    fontSize: PropTypes.number
+  }),
+
+  // You can chain any of the above with `isRequired` to make sure a warning
+  // is shown if the prop isn't provided.
+  requiredFunc: PropTypes.func.isRequired,
+
+  // A value of any data type
+  requiredAny: PropTypes.any.isRequired,
+
+  // You can also specify a custom validator. It should return an Error
+  // object if the validation fails. Don't `console.warn` or throw, as this
+  // won't work inside `oneOfType`.
+  customProp: function(props, propName, componentName) {
+    if (!/matchme/.test(props[propName])) {
+      return new Error(
+        'Invalid prop `' + propName + '` supplied to' +
+        ' `' + componentName + '`. Validation failed.'
+      );
+    }
+  },
+
+  // You can also supply a custom validator to `arrayOf` and `objectOf`.
+  // It should return an Error object if the validation fails. The validator
+  // will be called for each key in the array or object. The first two
+  // arguments of the validator are the array or object itself, and the
+  // current item's key.
+  customArrayProp: PropTypes.arrayOf(function(propValue, key, componentName, location, propFullName) {
+    if (!/matchme/.test(propValue[key])) {
+      return new Error(
+        'Invalid prop `' + propFullName + '` supplied to' +
+        ' `' + componentName + '`. Validation failed.'
+      );
+    }
+  })
+};

languages/bash.sh

@@ -233,7 +233,7 @@ str1 > str2               # str1 is greater than str2 (alphabetically)
 -e file                   # file exists; same -a
 -f file                   # file exists and is a regular file (i.e., not a directory or other special type of file)
 -r file                   # you have read permission
--r file                   # file exists and is not empty
+-s file                   # file exists and is not empty
 -w file                   # your have write permission
 -x file                   # you have execute permission on file, or directory search permission if it is a directory
 -N file                   # file was modified since it was last read

tools/docker.sh

@@ -20,6 +20,8 @@ docker login                                # Log in this CLI session using your
 docker tag <image> username/repository:tag  # Tag <image> for upload to registry
 docker push username/repository:tag         # Upload tagged image to registry
 docker run username/repository:tag          # Run image from a registry
+docker system prune                         # Remove all unused containers, networks, images (both dangling and unreferenced), and optionally, volumes. (Docker 17.06.1-ce and superior)
+docker system prune -a                      # Remove all unused containers, networks, images not just dangling ones (Docker 17.06.1-ce and superior)
 
 
 ##############################################################################

tools/kubernetes.sh

@@ -0,0 +1,117 @@
+##############################################################################
+# KUBERNETES
+# PDF: https://sematext.com/kubernetes-cheat-sheet/
+# WEBSITE: https://kubernetes.io/
+# DOCUMENTATION: https://kubernetes.io/docs/home
+##############################################################################
+
+
+##############################################################################
+# CLIENT CONFIGURATION
+##############################################################################
+
+
+# Setup autocomplete in bash; bash-completion package should be installed first
+source <(kubectl completion bash)
+
+# View Kubernetes config
+kubectl config view
+
+# View specific config items by json path
+kubectl config view -o jsonpath='{.users[?(@.name == "k8s")].user.password}'
+
+# Set credentials for foo.kuberntes.com
+kubectl config set-credentials kubeuser/foo.kubernetes.com --username=kubeuser --password=kubepassword
+
+
+##############################################################################
+# VIEWING, FINDING RESOURCES
+##############################################################################
+
+
+# List all services in the namespace
+kubectl get services
+
+# List all pods in all namespaces in wide format
+kubectl get pods -o wide --all-namespaces
+
+# List all pods in json (or yaml) format
+kubectl get pods -o json
+
+# Describe resource details (node, pod, svc)
+kubectl describe nodes my-node
+
+# List services sorted by name
+kubectl get services --sort-by=.metadata.name
+
+# List pods sorted by restart count
+kubectl get pods --sort-by='.status.containerStatuses[0].restartCount'
+
+# Rolling update pods for frontend-v1
+kubectl rolling-update frontend-v1 -f frontend-v2.json
+
+# Scale a replicaset named 'foo' to 3
+kubectl scale --replicas=3 rs/foo
+
+# Scale a resource specified in "foo.yaml" to 3
+kubectl scale --replicas=3 -f foo.yaml
+
+# Execute a command in every pod / replica
+for i in 0 1; do kubectl exec foo-$i -- sh -c 'echo $(hostname) > /usr/share/nginx/html/index.html'; done
+
+
+##############################################################################
+# MANAGE RESOURCES
+##############################################################################
+
+
+# Get documentation for pod or service
+kubectl explain pods,svc
+
+# Create resource(s) like pods, services or daemonsets
+kubectl create -f ./my-manifest.yaml
+
+# Apply a configuration to a resource
+kubectl apply -f ./my-manifest.yaml
+
+# Start a single instance of Nginx
+kubectl run nginx --image=nginx
+
+# Create a secret with several keys
+cat <<EOF | kubectl create -f -
+apiVersion: v1
+kind: Secret
+metadata:
+ name: mysecret
+type: Opaque
+data:
+ password: $(echo "s33msi4" | base64)
+ username: $(echo "jane"| base64)
+EOF
+
+# Delete a resource
+kubectl delete -f ./my-manifest.yaml
+
+
+##############################################################################
+# MONITORING & LOGGING
+##############################################################################
+
+
+# Deploy Heapster from Github repository
+kubectl create -f deploy/kube-config/standalone/
+
+# Show metrics for nodes
+kubectl top node
+
+# Show metrics for pods
+kubectl top pod
+
+# Show metrics for a given pod and its containers
+kubectl top pod pod_name --containers
+
+# Dump pod logs (stdout)
+kubectl logs pod_name
+
+# Stream pod container logs (stdout, multi-container case)
+kubectl logs -f pod_name -c my-container