working version

.gitignore

@@ -0,0 +1,2 @@
+node_modules
+npm-debug.log

README.md

@@ -9,8 +9,9 @@ Service Discoverer node module
 
 ## Use
 
-    VASCO_HOST=localhost VASCO_PORT=6379 VASCO_PASS=redispassword \
-    node app.js
+    VASCO_URL=127.0.0.1:6379 node app.js
+
+If not supplied, `VASCO_URL` gets the default value `127.0.0.1:6379`.
 
 Inside `app.js`,
 
@@ -22,7 +23,7 @@ Inside `app.js`,
         return;
       }
       // deps is a hash of dependency names (as defined in package.json)
-      // with active urls ensure to be active
+      // with active urls
       console.log(deps);
     });
 

examples/service/index.js

@@ -0,0 +1,26 @@
+var pick = require('object-pick');
+var vasco = require('../..');
+var ip = require('ip').address();
+var log = require('debug')('example:service');
+var app = require('express')();
+
+app.get('/', function (req, res) {
+  res.json({ ping: 'PONG' });
+});
+
+app.listen(function() {
+  var port = this.address().port;
+  var address = ip + ':' + port;
+  var pkg = require('./package');
+  log('address', address);
+
+  vasco.register(address, pkg, function (err, depUrls) {
+    if (err) {
+      console.error('Could not register self as service');
+      throw err;
+    }
+    log('depUrls', depUrls);
+    app.set('depUrls', depUrls);
+    log('started!');
+  });
+});

examples/service/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "service",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "DEBUG=* node index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "express": "^4.13.4",
+    "ip": "^1.1.0",
+    "object-pick": "^0.1.2"
+  }
+}

examples/user/index.js

@@ -0,0 +1,39 @@
+var vasco = require('../..');
+var request = require('request');
+var log = require('debug')('example:user');
+var ip = require('ip').address();
+var app = require('express')();
+
+app.get('/', function (req, res) {
+  var depUrls = app.get('depUrls');
+  if (!depUrls || !depUrls.service) {
+    return res.status(500).send('Service dependencies not available yet');
+  }
+  log('deps.service', depUrls.service);
+  var url = 'http://' + depUrls.service;
+  request.get({ url: url, json: true }, function (err, response, body) {
+    if (err) { return res.status(500).send(err.message); }
+    if (response.statusCode !== 200) {
+      return res.status(response.statusCode).send(body);
+    }
+    log('body', body);
+    if (body.ping !== 'PONG') {
+      return res.status(404).send('Incorrect response from service: ' + body);
+    }
+    res.send('success!');
+  });
+});
+
+app.listen(process.env.SERVICE_PORT, function () {
+  var address = ip + ':' + this.address().port;
+  var pkg = require('./package');
+  log('address', address);
+  vasco.register(address, pkg, function (err, depUrls) {
+    if (err) {
+      console.error('Could not register with vasco');
+      throw err;
+    }
+    log('depUrls', depUrls);
+    app.set('depUrls', depUrls);
+  });
+});

examples/user/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "user",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "DEBUG=* node index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "express": "^4.13.4",
+    "ip": "^1.1.0",
+    "request": "^2.69.0"
+  },
+  "vasco": {
+    "dependencies": {
+      "service": "1.0.0",
+      "auth": "1.0.0"
+    },
+    "mocks": {
+      "auth": "localhost:3000"
+    }
+  }
+}

index.js

@@ -0,0 +1,93 @@
+const redis = global.redis || require('redis');
+const log = require('debug')('vasco');
+
+let db;
+function connectDB() {
+  db = redis.createClient(process.env.VASCO_URL);
+  db.on('error', err => { throw err; });
+}
+
+function findDependencies(dependencies, mockDeps, done) {
+  const depUrls = {};
+  const depNames = Object.keys(dependencies);
+  const depKeys = depNames.map(depName => depName + '@' + dependencies[depName]);
+  log('depKeys', depKeys);
+
+  let total = depKeys.length;
+  if (!total) { return done(null, {}); }
+
+  depNames.forEach((depName, index) => {
+    if (mockDeps[depName]) { return gotMockDepUrl(depName, mockDeps[depName]); }
+    const key = depKeys[index];
+    const dbKey = 'endpoints.' + key;
+    db.srandmember(dbKey, gotDepUrl(depName, key, dbKey));
+  });
+
+  function gotDepUrl(depName, key, dbKey) {
+    return (err, url) => {
+      if (err) { return done(err); }
+      if (!url) { return done(new Error('No service found for ' + key)); }
+      log('url for dep', key, url);
+
+      db.get('alive.' + url, (err, alive) => {
+        if (err) { return done(err); }
+        log('url alive:', url, alive);
+        if (!alive) {
+          return db.srem(dbKey, url, err => {
+            if (err) { return done(err); }
+            db.srandmember(dbKey, gotDepUrl(key, dbKey));
+          });
+        }
+        log('url for alive dep', key, url);
+        depUrls[depName] = url;
+        total -= 1;
+        if (!total) { return done(null, depUrls); }
+      });
+    };
+  }
+  function gotMockDepUrl(depName, url) {
+    if (!url) { return done(new Error('No mock service found for', depName)); }
+    depUrls[depName] = url;
+    total -= 1;
+    if (!total) { return done(null, depUrls); }
+  }
+}
+
+function register(url, pkg, done) {
+  if (!url) { return done(new Error('Need url of service')); }
+  if (!pkg || !pkg.name || !pkg.version) { return done(new Error('Invalid package')); }
+  const opts = pkg.vasco || {};
+  const aliveDuration = opts.aliveDuration || 10; // seconds
+
+  connectDB();
+  findDependencies(opts.dependencies || {}, opts.mocks || {}, (err, depUrls) => {
+    if (err) { return done(err); }
+    const name = pkg.name + '@' + pkg.version;
+    db.sadd('endpoints.' + name, url, err => {
+      if (err) { return done(err); }
+      db.end(true);
+      pingHealth(url, err => {
+        if (err) { return done(err); }
+        setInterval(pingHealth, aliveDuration * 1000, url);
+        done(null, depUrls);
+      });
+    });
+  });
+
+  function pingHealth(url, callback) {
+    const key = 'alive.' + url;
+    callback = callback || (err => { if (err) throw err; });
+
+    connectDB();
+    db.set(key, true, err => {
+      if (err) { return callback(err); }
+      db.expire(key, aliveDuration, err => {
+        callback(err);
+        db.end(true);
+      });
+    });
+  }
+}
+
+module.exports = { findDependencies, register };
+

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "vasco",
+  "version": "1.0.0",
+  "description": "The Great Service Discoverer",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "Anup Bishnoi <[email protected]>",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "redis": "^2.4.2"
+  }
+}