Post to slack webhook should be done on remote app server

[halida]

Slack webhook url is configured in deploy.rb now, but it may cause problems:

• If slack webhook url is saved in git repo, it may cause security leak for slack.
• If slack webhook url is saved under local config file, every developer should set webhook url on their local config, which may lead to inconsistent: If webhook url is updated, and one of the developer didn't update it, His deploy operation cannot notify slack.

So I think the good solution is like this:

• Post to slack webhook url should be done on remote app server
• Remote app server should save webhook url on an config file

Example:

• Gemfile should add gem 'slackistrano', require: false for production
• slack:deploy:updated should run an slackistrano rake task on app server, like: https://github.com/airbrake/airbrake/blob/master/lib/airbrake/capistrano/tasks.rb#L10
• slackistrano rake task post slack webhook url

It may changes a lot and make things complicate, but I think it is the good practice.

[phallstrom]

Interesting idea, but I don't think I'm going to make this change as it would disrupt too many existing installations. I'll leave this here though and if enough folks +1 I'll reconsider. Maybe could make it an optional config "notify from server" option even.

[thbar]

@halida did you find a way to achieve this with slackistrano? (or maybe with another solution?)