jasonpincin / node-consulite

Tiny consul Node.js module for client discovery

consulite

Tiny consul Node.js module for client discovery with round-robin support

API

The consul instance to connect to can be configured either through the config() function or through the following environment variables:

• CONSUL_HOST: defaults to 'consul'
• CONSUL_PORT: defaults to 8500

config(config)

Configure consulite with any of the following settings

• consul - the base URL to use to connect to consul

getService(name [, callback])

Get service address information from cache or from consul. When multiple service instances are registered with consul the first instance that hasn't been executed or the oldest executed service is returned.

• name: the service name registered with consul. If no services are found then an error will be returned to the callback. If multiple services are found then the service that hasn't been executed or hasn't been executed most recently will be returned in the callback.

• callback: function with the signature (err, service) where service has the following properties:

  • address: the host address where the service is located
  • port: the port that the service is exposed on

This function returns a Promise if no callback is provided.

getServiceHosts(name [, callback])

Get an array of all service instances from cache or from consul.

• name: the service name registered with consul. If no services are found then an error will be returned to the callback.

• callback: function with the signature (err, hosts) where hosts is an array of objects with the following properties:

  • address: the host address where the service is located
  • port: the port that the service is exposed on

This function returns a Promise if no callback is provided.

getCachedService(name)

Get the next service from the cache if it exists, otherwise return null;

getCachedServiceHosts(name)

Get an array of all service instances from the cache if it exists, otherwise null.

refreshService(name [, callback])

Makes a request to consul for the given service name and caches the results. Only services that are healthy are cached.

• name: the service name to fetch from consul.
• callback: function with signature (err, services)

This function returns a Promise if no callback is provided.

Example Usage

const Consulite = require('consulite');
const Wreck = require('wreck');

Consulite.getService('users', (err, service) {
  if (err) {
    console.error(err);
    return;
  }

  Wreck.get(`http://${service.address}:${service.port}/users`, (err, res, payload) => {
    // handle error and do something with results
  });
});

If you want to set the consul address to use and don't want to depend on environment variables you can use the config() function as demonstrated below:

const Consulite = require('consulite');
const Wreck = require('wreck');

Consulite.config({ consul: 'http://myconsul.com' });

Consulite.getService('users', (err, service) {
  if (err) {
    console.error(err);
    return;
  }

  Wreck.get(`http://${service.address}:${service.port}/users`, (err, res, payload) => {
    // handle error and do something with results
  });
});