Add support for enviroment variables configuration and add Heroku Pro…

…cfile.

Procfile

@@ -0,0 +1 @@
+worker: PORT=$LIMITD_PORT node bin/limitd

README.md

@@ -56,6 +56,7 @@ On other systems use node.js and npm:
 npm i -g limitd
 ```
 
+#### Configuration with a config file
 Create a file named `limitd.config` for the server settings:
 ```yaml
 #port to listen on
@@ -80,6 +81,34 @@ You can find all configuration options [below](#server_options).
 
 > **Note**: For production you would create a daemon (upstart, systemd, initd, etc.) that runs the aforementiond command.
 
+#### Configuration with environment variables
+```bash
+#port to listen on
+export PORT=9001
+
+#db path
+export DB=/var/limitd/database
+
+#define the bucket types
+export BUCKET_1_NAME=user
+export BUCKET_1_SIZE=10
+export BUCKET_1_PER_SECOND=5
+
+export BUCKET_2_NAME=some_other_bucket
+export BUCKET_2_SIZE=25
+export BUCKET_2_PER_MINUTE=15
+```
+> **Note**: Using enviroment variables for buckets has a limitation. The `override` config parameter is not supported yet.
+
+Start the server:
+```bash
+limitd
+```
+
+You can find all configuration options [below](#server_options).
+
+> **Note**: For production you would create a daemon (upstart, systemd, initd, etc.) that runs the aforementiond command.
+
 ## Motivation
 
 While there are many solutions that relies on a central database like redis, these solutions tipically put all the configuration, limits and logic on the application side.

bin/limitd

@@ -9,6 +9,7 @@ const yaml     = require('js-yaml');
 const _        = require('lodash');
 const profiler = require('v8-profiler');
 const getLogger  = require('../lib/logger');
+const configEnvParser = require('../conf/config.env.parser');
 
 const LimitdServer = require('../server');
 
@@ -37,6 +38,16 @@ if (config.configFile) {
   }
 }
 
+try{
+  const parsed = configEnvParser.parse(process.env);
+  _.extend(config, parsed);
+} catch (e) {
+  console.error('Error parsing environment configuration\n', e.stack);
+  setTimeout(function () {
+    process.exit(2);
+  }, 500);
+}
+
 const logger = getLogger(config.log_level);
 
 if (typeof config.db === 'undefined') {

conf/config.env.parser.js

@@ -0,0 +1,67 @@
+'use strict';
+
+const _ = require('lodash');
+const schema = require('./config.schema');
+const propertyNames = Object.keys(schema.properties);
+
+function parseString(name, value) {
+  const subschema = schema.properties[name];
+
+  return parseStringToSpecificType(value, subschema.type);
+}
+
+function parseBucketString(name, value) {
+  const objectName = Object.keys(schema.properties.buckets.patternProperties)[0];
+  const subschema = schema.properties.buckets.patternProperties[objectName].properties[name];
+
+  return parseStringToSpecificType(value, subschema.type);
+}
+
+function parseStringToSpecificType(value, type) {
+  let parsed;
+  if (type === 'string' || Array.isArray(type) && type.indexOf('string') > -1) {
+    return value;
+  }
+  switch (type) {
+    case 'integer':
+      parsed = Number(value);
+      break;
+    case 'boolean':
+      parsed = Boolean(value);
+      break;
+  }
+
+  return parsed;
+}
+
+module.exports.parse = function (env) {
+  const keys = Object.keys(env);
+  const config = {};
+  const buckets = {};
+
+  keys.forEach(key => {
+    if (key.indexOf('BUCKET') === 0) {
+      const id = key.split('_')[1];
+      if (key !== `BUCKET_${id}_NAME`) {
+        const bucketName = env[`BUCKET_${id}_NAME`];
+        let bucket = buckets[bucketName];
+        if (!bucket) {
+          bucket = {};
+          buckets[bucketName] = bucket;
+        }
+        const propertyName = key.replace(`BUCKET_${id}_`, '').toLowerCase();
+        bucket[propertyName] = parseBucketString(propertyName, env[key]);
+      }
+
+    } else if(propertyNames.indexOf(key.toLowerCase()) > -1) {
+      const propertyName = key.toLowerCase();
+      config[propertyName] = parseString(propertyName, env[key]);
+    }
+  });
+
+  if (!_.isEmpty(buckets)) {
+    config.buckets = buckets;
+  }
+
+  return config;
+};

test/config.env.parser.tests.js

@@ -0,0 +1,112 @@
+const expect = require('chai').expect;
+const parser = require('../conf/config.env.parser');
+
+describe('config env parser', function() {
+  describe('with a complete well formed environment', function () {
+    const env = {
+      PORT: '9001',
+      BUCKET_1_NAME: 'user',
+      BUCKET_1_SIZE: '1',
+      BUCKET_1_PER_MINUTE: '5',
+      BUCKET_1_PURPOSE: 'user creation bucket',
+      BUCKET_2_NAME: 'foo',
+      BUCKET_2_SIZE: '10',
+      BUCKET_2_PER_MINUTE: '15',
+      BUCKET_2_MATCH: '^[a-zA-Z0-9]+$',
+      BUCKET_3_NAME: 'bar',
+      BUCKET_3_UNLIMITED: 'true',
+      DB: './database'
+    };
+
+    it('should parse it ok', function() {
+      const config = parser.parse(env);
+      expect(Object.keys(config).length).to.equal(3);
+      expect(config.port).to.equal('9001');
+      expect(config.db).to.equal('./database');
+      expect(config.buckets).to.deep.equal({
+        user: { size: 1, per_minute: 5, purpose: 'user creation bucket' },
+        foo: { size: 10, per_minute: 15, match: '^[a-zA-Z0-9]+$' },
+        bar: { unlimited: true }
+      });
+    });
+  });
+
+  describe('with just the buckets configuration in the environment', function () {
+    const env = {
+      BUCKET_1_NAME: 'user',
+      BUCKET_1_SIZE: 1,
+      BUCKET_1_PER_MINUTE: 5,
+      BUCKET_2_NAME: 'foo',
+      BUCKET_2_SIZE: 10,
+      BUCKET_2_PER_MINUTE: 15,
+      BUCKET_3_NAME: 'bar',
+      BUCKET_3_SIZE: 13,
+      BUCKET_3_PER_SECOND: 25,
+    };
+
+    it('should parse it ok', function() {
+      const config = parser.parse(env);
+      expect(Object.keys(config).length).to.equal(1);
+      expect(config.buckets).to.deep.equal({
+        user: { size: 1, per_minute: 5 },
+        foo: { size: 10, per_minute: 15 },
+        bar: { size: 13, per_second: 25 }
+      });
+    });
+  });
+
+  describe('with just the buckets configuration in the environment in a random order', function () {
+    const env = {
+      BUCKET_3_PER_SECOND: 25,
+      BUCKET_1_SIZE: 1,
+      BUCKET_2_NAME: 'foo',
+      BUCKET_1_PER_MINUTE: 5,
+      BUCKET_2_SIZE: 10,
+      BUCKET_3_NAME: 'bar',
+      BUCKET_2_PER_MINUTE: 15,
+      BUCKET_1_NAME: 'user',
+      BUCKET_3_SIZE: 13,
+    };
+
+    it('should parse it ok', function() {
+      const config = parser.parse(env);
+      expect(Object.keys(config).length).to.equal(1);
+      expect(config.buckets).to.deep.equal({
+        user: { size: 1, per_minute: 5 },
+        foo: { size: 10, per_minute: 15 },
+        bar: { size: 13, per_second: 25 }
+      });
+    });
+  });
+
+  describe('with not supported additional properties', function () {
+    const env = {
+      PORT: '9001',
+      BUCKET_1_NAME: 'user',
+      BUCKET_1_SIZE: '1',
+      BUCKET_1_PER_MINUTE: '5',
+      BUCKET_2_NAME: 'foo',
+      BUCKET_2_SIZE: '10',
+      BUCKET_2_PER_MINUTE: '15',
+      BUCKET_3_NAME: 'bar',
+      BUCKET_3_SIZE: '13',
+      BUCKET_3_PER_SECOND: '25',
+      DB: './database',
+
+      ADDITIONAL_PROPERTY_1: 'baz',
+      additional_property_2: 'taz'
+    };
+
+    it('should not include additional properties', function() {
+      const config = parser.parse(env);
+      expect(Object.keys(config).length).to.equal(3);
+      expect(config.port).to.equal('9001');
+      expect(config.db).to.equal('./database');
+      expect(config.buckets).to.deep.equal({
+        user: { size: 1, per_minute: 5 },
+        foo: { size: 10, per_minute: 15 },
+        bar: { size: 13, per_second: 25 }
+      });
+    });
+  });
+});