* Refactoring and documentation

README.md

@@ -1,2 +1,10 @@
 # ipv6-global-ip-demo
 A simple web application to test whether your ISP provides you 2^64 ipv6 global IP or not
+
+## Usage
+
+* clone the repo
+* run `npm install` or `yarn install`
+* export environment variable `ETH_DEV` which points to ether net interface with public IPv6 address.
+* Run server . Eg: `env ETH_DEV=em1 npm run server`, where em1 is the ether net interface with global IPv6 IP.
+* Open [http://127.0.0.1:3553/] in the browser to access the application

index.js

@@ -6,16 +6,17 @@
 const Koa = require('koa');
 const Router = require('koa-joi-router');
 const util = require('util');
+const {RateLimiterMemory} = require('rate-limiter-flexible');
+
 
 const app = new Koa();
 const router = new Router();
 const Joi = Router.Joi;
 const _exec = util.promisify( require('child_process').exec );
 const ethDev = process.env.ETH_DEV
-const {RateLimiterMemory} = require('rate-limiter-flexible');
 const rateLimitOpts = {
-  points: 1, // 1 request for ctx.ip
-  duration: 1, // per 1 second
+  points: 5, // 1 request for ctx.ip
+  duration: 5, // per 1 second
 };
 const rateLimiter = new RateLimiterMemory( rateLimitOpts );
 const MyJoi = {
@@ -23,7 +24,8 @@ const MyJoi = {
     return Joi.string().ip({
       version: [
         'ipv6'
-      ]
+      ],
+      cidr: 'forbidden'
     })
   },
   ipv6Array: function(){
@@ -41,6 +43,64 @@ async function exec( cmd ){
 }
 
 
+function setRateLimitHeader( ctx, rateLimitInfo ){
+  ctx.response.set({
+    "X-RateLimit-Limit": rateLimitOpts.points,
+    "X-RateLimit-Remaining": rateLimitInfo.remainingPoints,
+    "X-RateLimit-Reset": new Date(Date.now() + rateLimitInfo.msBeforeNext).toUTCString()
+  });
+}
+
+
+async function rateLimiterMiddleWare( ctx, next ){
+  try {
+    let rlInfo = await rateLimiter.consume(ctx.ip)
+    setRateLimitHeader( ctx, rlInfo );
+    await next().catch();
+  } catch ( rlInfo ) {
+    ctx.status = 429
+    ctx.response.set({
+      "Retry-After": rlInfo.msBeforeNext / 1000,
+    });
+    setRateLimitHeader( ctx, rlInfo );
+    ctx.body = { error: 'Too Many Requests. Please wait for some time' };
+  }
+}
+
+
+async function getIpList( ctx ){
+  const ips = await exec(`ip -6  a show dev ${ethDev} scope global | grep inet6 | awk '{print $2}'`)
+  ctx.body = { ips : ips.split('\n').filter(v => v.length ).map( v => v.slice(0, -3)) };
+}
+
+
+async function addIp( ctx ){
+  const ip = ctx.request.body.ip;
+  try {
+    await exec(`sudo ip -6 a add ${ip}/64 dev ${ethDev}`);
+  } catch (e) {
+    ctx.status = 409;
+    ctx.body = { error: 'Failed to assign ip'};
+    return;
+  }
+
+  // Remove ip after some time
+  setTimeout(function(){
+    exec(`sudo ip -6 a del dev ${ethDev} ${ip}/64`);
+  },60*1000 );
+
+  const ips = await exec(`ip -6  a show dev ${ethDev}| grep inet6.*global | awk '{print $2}'`);
+  ctx.body = { ips : ips.split('\n').filter(v => v.length ).map( v => v.slice(0, -3)) };
+}
+
+
+async function logger( ctx, next ){
+  const startTime = Date.now();
+  await next();
+  const requestTime = Date.now() - startTime;
+  console.log(`${ctx.method} ${ctx.response.status} ${ctx.ip} "${ctx.request.headers['user-agent']}" - ${requestTime}`);
+}
+
 
 router.route({
   method: 'get',
@@ -54,10 +114,7 @@ router.route({
       }
     }
   },
-  handler: async (ctx) => {
-    const ips = await exec(`ip -6  a show dev ${ethDev} scope global | grep inet6 | awk '{print $2}'`)
-    ctx.body = { ips : ips.split('\n').filter(v => v.length ).map( v => v.slice(0, -3)) };
-  }
+  handler: getIpList
 });
 
 
@@ -77,43 +134,13 @@ router.route({
       }
     }
   },
-  handler: async (ctx) => {
-    const ip = ctx.request.body.ip;
-    try {
-      await exec(`sudo ip -6 a add ${ip}/64 dev ${ethDev}`);
-    } catch (e) {
-      ctx.status = 409;
-      ctx.body = { error: 'Failed to assign ip'};
-      return;
-    }
-
-    // Remove ip after some time
-    setTimeout(function(){
-      exec(`sudo ip -6 a del dev ${ethDev} ${ip}/64`);
-    },60*1000 );
-
-    const ips = await exec(`ip -6  a show dev ${ethDev}| grep inet6.*global | awk '{print $2}'`);
-    ctx.body = { ips : ips.split('\n').filter(v => v.length ).map( v => v.slice(0, -3)) };
-  }
+  handler: addIp
 });
 
 
-app.use(require('koa-static')('./static'));
-app.use( async ( ctx, next ) => {
-  try {
-    await rateLimiter.consume(ctx.ip)
-    await next();
-  } catch (rejRes) {
-    ctx.status = 429
-    ctx.response.set({
-      "Retry-After": rejRes.msBeforeNext / 1000,
-      "X-RateLimit-Limit": rateLimitOpts.points,
-      "X-RateLimit-Remaining": rejRes.remainingPoints,
-      "X-RateLimit-Reset": new Date(Date.now() + rejRes.msBeforeNext)
-    });
-    ctx.body = { error: 'Too Many Requests. Please wait for some time' };
-  }
-});
-app.use(router.middleware());
+app.use( logger );
+app.use( require('koa-static')('./static') );
+app.use( rateLimiterMiddleWare );
+app.use( router.middleware() );
 app.listen( 3553 );
 

static/app.js

@@ -46,8 +46,7 @@ var app = new Vue({
           this.ips = res.ips;
         })
         .catch( res =>{
-          console.log( res );
-          // alert( res.error )
+          alert( res.error )
         });
     }
   }

static/index.html

@@ -5,11 +5,19 @@
     <title>IPV6 global ip test</title>
   </head>
   <body>
+    <h2>What is this?</h2>
+    <pre>
+      * List of public IPv6 IP assigned to the currently running server is shown below.
+      * We can click on each link and verify whether that IP is globally accessible or not by visiting the link
+      * Optionally, we can add new public IPv6 address using the form displayed in the bottom.
+      * Newly added IP will only persist for one minute. It will be removed after that.
+      * Please note that, we are only allowed change last 64 bits of existing global ip. Otherwise it won't work
+    </pre>
     <div id="app">
       <h3>List of global IPv6 address assigned to this server</h3>
       <ul id="cont-ip-list">
         <li v-for="ip in ips">
-          <a :href="'http://[' + ip + ']:3553'">
+          <a target="_blank" :href="'http://[' + ip + ']:3553'">
           {{ ip }}
           </a>
         </li>