briareus/lib/service/actions/create-alb-rule.js

Briareus assists with Feature Branch deploys to ECS

'use strict'

const AWS = require('aws-sdk');

let action = module.exports = function (pipeline, payload, cb) {
  const elbv2 = new AWS.ELBv2();

  function createAlbRule(done) {
    // Generate random priority. No two rules can have the same priority.
    // Not true random, but this doesn't have to be cryptographically secure random
    // We'll just try again if we pick a number that is already in use
    let randomPriority = Math.random() * (999 - 1) + 1;
    let params = {
      Actions: [{
        TargetGroupArn: payload.assets.targetGroup.arn,
        Type: 'forward'
      }],
      Conditions: [
        {
          Field: 'host-header',
          Values: [`*${payload.endpoint.host}`]
        }],
      ListenerArn: payload.alb.listenerArn,
      Priority: randomPriority
    };

    elbv2.createRule(params, (err, data) => {
      if (err) {
        // If we randomly chose a priority that has already been used. Try again
        if (err.code === 'PriorityInUse') return createAlbRule(done);
        return cb(err);
      }

      cb(null, [
        { op: 'add', path: '/assets/albRule', value: { arn: data.Rules[0].RuleArn } },
      ]);
    });
  }

  createAlbRule(cb);
};

action.waiting = 'Creating routing rule on ALB';
action.done = 'Routing rule on ALB has been created';