tribune/lib/consul.js

Holy advocate to the Roman Senate, your Tribune will ensure the Consuls have your interests in mind.

const request = require('request');

class Consul {

  constructor(opts) {
    this._request  = request.defaults(opts);
    this._agentUrl = opts.agentUrl;
    this._aclToken = opts.aclToken;

    this.service = {
      get       : (...args) => this._getServices(...args),
      register  : (...args) => this._registerService(...args),
      deregister: (...args) => this._deregisterService(...args),
      checks    : (...args) => this._checkServices(...args)
    };

    this.preparedQuery = {
      register  : (...args) => this._registerPreparedQuery(...args),
      deregister: (...args) => this._deregisterPreparedQuery(...args),
      execute   : (...args) => this._executePreparedQuery(...args),
      get       : (...args) => this._getPreparedQueries(...args)
    };
  }


  getLeader(cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/status/leader`, { json: true }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to get consul leader. Consul responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }

  getPeers(cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/status/peers`, { json: true }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to get consul peers. Consul responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }

  _getServices(cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/agent/services`, { json: true }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to get consul agent services. Tribune agent responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }

  _registerService(body, cb = () => {}) {
    const qs = this._aclToken ? `?=${this._aclToken}` : '';
    this._request.put(`${this._agentUrl}/v1/agent/service/register${qs}`, {
      json: body
    }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to register with Tribune. Tribune agent responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null);
    });
  }

  _deregisterService(id, cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/agent/service/deregister/${id}`, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to deregister service from Consul. Consul agent responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null);
    });
  }

  _checkServices(cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/agent/checks`, { json: true }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to get agent checks from Consul. Consul agent responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }

  _registerPreparedQuery(body, cb = () => {}) {
    this._request.post(`${this._agentUrl}/v1/query`, {
      json: body
    }, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to register prepared query. Consul responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null, res.body.ID);
    });
  }

  _deregisterPreparedQuery(id, cb = () => {}) {
    this._request.delete(`${this._agentUrl}/v1/query/${id}`, (err, res) => {
      if (err) { return cb(err); }

      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to deregister prepared query. Consul responded with a status ' +
          `code of ${res.statusCode}`
        ));
      }

      cb(null);
    });
  }

  _getPreparedQueries(cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/query`, { json: true }, (err, res) => {
      if (err) { return cb(err); }
      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to get consul prepared queries. Consul responded ' +
          `with a status code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }

  _executePreparedQuery(service, limit, cb = () => {}) {
    this._request.get(`${this._agentUrl}/v1/query/${service}/execute`, {
      json: true, qs: { limit }
    }, (err, res) => {
      if (err) { return cb(err); }
      if (res.statusCode === 404) { return cb(null); }
      if (res.statusCode !== 200) {
        return cb(new Error(
          'Failed to execute consul prepared query. Consul responded ' +
          `with a status code of ${res.statusCode}`
        ));
      }

      cb(null, res.body);
    });
  }
}

module.exports = Consul;