sails-hook-zkconfig

Sails hook，load config from zookeeper synchronously.

Install

$ npm install sails-hook-zkconfig --save

Usage

If some of configuration in your sails app need to be loaded from zookeeper, such as, connections of mysql or redis in config/connections.js or config/env/*.js, just add zookeeper config in config/env/*.js. Configuration will be updated from zookeeper automatically, before orm, service use.

Put zkPath in your config to be updated from zookeeper, and value is zookeeper path.

First, if config is json, such as, redis config {"host": "127.0.0.1", "port": 6379} stored in zookeeper path /config/redis.

module.exports = {
  zkHost: '127.0.0.1:2181,192.168.1.1:2181', // Zookeeper hosts, seperated by comma
  redisServer: {
    zkPath: '/config/redis'  // Zookeeper path for redis
  },
 
  redisServers: [{
    db: 0,
    zkPath: '/config/redis'  // Zookeeper path for redis
  }, {
    db: 1,
    zkPath: '/config/redis' // Zookeeper path for redis
  }]
};

Configuration after updated.

module.exports = {
  zkHost: '127.0.0.1:2181,192.168.1.1:2181',
  redisServer: {
    host: '127.0.0.1',
    port: 6379
  },
 
  redisServers: [{
    db: 0,
    host: '127.0.0.1',
    port: 6379
  }, {
    db: 1,
    host: '127.0.0.1',
    port: 6379
  }]
};

Second, config is plaintext, such as, 'my_secret_key' stored in zookeeper path /config/secret.

module.exports = {
  zkHost: '127.0.0.1:2181,192.168.1.1:2181',
  appKey1: '/config/secret',
  appKey2: {
    zkPath: '/config/secret'
  },
  zkKeys: ['appKey1']
};

Configuration after updated.

module.exports = {
  zkHost: '127.0.0.1:2181,192.168.1.1:2181',
  appKey1: '__my_secret_key__',
  appKey2: '__my_secret_key__',
  zkKeys: ['appKey1']
};

Use zkKeys to specify the key need to updated and the key's value is zookeeper path, it is the difference with zkPath is that the value just set to the key and won't be assigned to parent. zkKeys.

When use zkPath and the value is json object, there is a way to override some key's value. Such as, /config/mysql set as {"adapter": "sails-mysql", "host": "127.0.0.1", "database": "test"}, and want to use a special adapter sails-mysql-override in one project.

module.exports = {
  mysql: {
    zkPath: '/config/mysql',
    zkOverride: {
      adapter: 'sails-mysql-override'
    }
  }
};

Configuration after updated.

module.exports = {
  mysql: {
   adapter: 'sails-mysql-override',
   host: '127.0.0.1',
   database: 'test'
  }
};

Use zkDefault to specify default config.

module.exports = {
  mysql: {
    zkPath: '/config/mysql',
    zkDefault: {
      adapter: 'sails-mysql-default',
      password: 'default_pwd'
    }
  },
  secret: {
    zkPath: '/config/secret',
    zkDefault: '__this_is_default_secret__'
  }
};

Configuration after updated when /config/mysql set as {"host": "127.0.0.1", database: "test"}.

module.exports = {
  mysql: {
   adapter: 'sails-mysql-default',
   host: '127.0.0.1',
   database: 'test',
   password: 'default_pwd'
  },
  secret: '__this_is_default_secret__'
};

Of course, you can also use hook in zkConfig.js to change key value before/after load.

Use zkRequired to check if the config exists.

module.exports = {
  mysql: {
   zkPath: '/config/mysql',
   zkRequired: true // Or `production` to check only in production environment
  },
  secret: '__this_is_default_secret__'
};

Use zkIgnore to skip config key.

module.exports = {
  mysql: {
   zkPath: '/config/mysql',
   zkIgnore: true
  }
};

Use zkDecoder to decode config value, default JSON.parse.

module.exports = {
  mysql: {
   zkPath: '/config/mysql',
   zkDecoder: (v)=>{
     return JSON.parse(Buffer.from(v, 'base64').toString())
   }
  }
};

Use zkAfter to adjust config value after config decoded and merged,

module.exports = {
  mysql: {
    zkPath: '/config/mysql',
    port: 3306, // value will not be passed to `zkAfter`
    zkDefault: { // values will be passed to `zkAfter`
      port: 3306
    },
    zkOverride: { // values will be passed to `zkAfter`
      adapter: 'sails-mysql-override'
    },
    zkAfter: (d)=>{
      d.url = `mysql://${d.user}:${d.password}@${d.host}:${d.port}/${d.database}`;
      return d;
    }
  }
};

Use zkInit to init config key when not exists.

module.exports = {
  mysql: {
   zkPath: '/config/key',
   zkInit: ()=>{
     return JSON.stringify({now: Date.now()});
   }
  }
};

Use zkReload to enable reload config key when needed.

module.exports = {
  mysql: {
   zkPath: '/config/key',
   zkReload: true,
  }
};
// reload when needed
sails.zkReloader.reload('sails.config.mysql', function(err, data){
  if (!err) {
    sails.config.mysql = data;
  }
});

Configuration

Change the default configuration by adding config/zkConfig.js under your sails project.

module.exports.zkConfig = {
  timeout: 30000, // Get config timeout
  enabled: true, // Enable zkConfig. Defaults to `true`
  zkKeys: ['appKey1'], // Keys to be updated.
  zkObjKey: 'zkPath', // Change the default `zkPath`
  zkHost: '127.0.0.1:2181,192.168.0.1:2181', // Zookeeper server list,
  before: function(config) { // hook before load config from zookeeper
 
  },
  after: function(config){ // hook after load config from zookeeper
 
  }
};

You can also config zkKeys as follow

module.exports.zkConfig = {
  zkKeys: {appKey1: '/config/same/key1', appKey2: '/config/same/key2'}
};

or more complex config

module.exports.zkConfig = {
  zkKeys: ['appKey1', {appKey2: '/config/same/key2'}]
};

Cache

Cache config when load successfully, and then load config from cache when failed to load config, or load from cache directly when cache not expire.

module.exports.zkConfig = {
  zkCache: {
    enabled: false, // default false
    expire: 0, // Cache expire time, load from cache when cache not epire.
    directory: process.env.HOME, // where cache to store
    filename: '', // cache filename
    secret: '' // encryption key
  }
};

Watcher

Watch config changes when load successfully. Watch in zkConfig.

module.exports.zkConfig = {
  zkWatcher: {
    enabled: false, // default false
    watch: (data, path)=>{
 
    }
  }
};

You can also use zkWatch with zkPath at anywhere.

module.exports = {
  mysql: {
    zkPath: '/config/mysql',
    zkWatch: (data, path)=>{
 
    }
  }
};

Also you can use sails.watchConfig(configPath, callback). For example, reload orm when connections are changed.

module.exports.bootstrap = function(cb) {
  sails.watchConfig('sails.config.connections', ()=>{
    sails.hooks.orm.reload();
  });
  cb();
};

Local

If there is no zookeeper server, you can use local file storage instead of zookeeper. There are two ways to set up local storage. The first way is to set the environment variable LOCAL_ZKCONFIG_PATH to point to the local configuration storage root directory, such as

export LOCAL_ZKCONFIG_PATH=/var/lib/local_zk

The second way is to configure zkHost to point to the local configuration storage root directory (can add the prefix file://), such as

module.exports = {
  zkHost: '/var/lib/local_zk',
  // zkHost: 'file:///var/lib/local_zk', // with the prefix `file://`
};

All data must be stored in zkPath relative to the storage root directory configured above, or with suffix .json. For example, the actual storage location of /config/mysql is /var/lib/local_zk/config/mysql or /var/lib/local_zk/config/mysql.json. The content of the file is a JSON containing a data field and a version field, data is the actual configuration content, version represents the configuration version. For example,

{"data":{"host":"127.0.0.1","port":3306},"version":1}

Or

{"data":"mysql://user:password@127.0.0.1:3306/database","version":1}

To share local configuration, also provide a simple http server

$ zk-local --base /var/lib/local_zk --port 5181 # global install 
$ ./node_modules/.bin/zk-local --base /var/lib/local_zk --port 5181 # project install 

and then configure zkHost to http://126.0.0.1:5181.

Variables

You can use the following variables as zkpath, only valid when using remote zookeeper not local file system.

• $address current zookeeper client address {"address":"","port":}
• $ip current zookeeper client ip
• $port current zookeeper client port

module.exports = {
  appHost: {
    zkPath: '$ip'
  }
}

API

sails.watchConfig(paths: string| Array.<string>, callback)

sails.watchConfig('sails.config.connections', ()=>{ // watch any changes in or under sails.config.connections
  sails.hooks.orm.reload();
});
 
sails.watchConfig('sails.config.redis1', ()=>{ // only watch changes in sails.config.redis1
  // reconnect redis1
});
 
sails.watchConfig(['sails.config.connections', 'sails.config.redis1'], ()=>{
});

sails.removeConfigWatcher(paths: string| Array.<string> [, callback])

Remove the watchers of the path(s). if a callback is specified, only remove the callback related watcher.

const cb = ()=>{};
sails.watchConfig('sails.config.connections', cb);
sails.watchConfig('sails.config.redis1', ()=>{
 
});
 
// All are removed.
sails.removeConfigWatcher(['sails.config.connections', 'sails.config.redis1']);
 
// Only `sails.config.connections` is removed
sails.removeConfigWatcher(['sails.config.connections', 'sails.config.redis1'], cb);