Capistrano Slack integration.

slack_notify.rake

# Capistrano Task that hooks into `deploy:finished` to send a message to Slack
#
# 1. Setup a Slack Incoming Webhook Integration (https://api.slack.com/incoming-webhooks)
# 2. Put the Webhook URL in an Environment variable (SLACK_WEBHOOK_URL)
# 3. Place this file in `lib/capistrano/tasks`
# 
# This will then create a new message in the channel on deployment, including who, what and where information

require "net/http"
require "json"
require "uri"

namespace :slack_notify do
  desc "Notify Slack of a deployment"
  task :deployed do
    url = ENV["SLACK_WEBHOOK_URL"]
    user = `git config user.name`.chomp
    branch = fetch(:branch)
    tag = `git describe --abbrev=0 --tags`.chomp
    stage = fetch(:stage)

    payload = {
      "username": fetch(:application),
      "text": "#{user} deployed branch #{branch} (#{tag}) to #{stage}.",
      "icon_url": "https://avatars2.githubusercontent.com/u/58257?v=3&s=40"
    }.to_json

    Net::HTTP.post_form(URI.parse(url), payload: payload)
  end
end

namespace :deploy do
  after :finished, "slack_notify:deployed"
end