Enable Post Scripts Process on Failure

[Phillita]

Motivation

I am currently trying to run a PoC of Shipit over our current manual deploy process. I noticed there are pre and post scripts that can be run, but I found out that on command errors, the post script won't be run.

My current system let's us know when deploys fail, and I think allowing post scripts to run on failure will get me the needed information in my secondary tracking system.

Changes

• Update the bundler discovery section to let the sed command work with modern macs (issue Disparate Ruby Versions #1371)
• Add config for post scripts on both deploy and rollback sections to run on_error
• Updated the code to allow for post scripts to run on command errors
• Added extra env config (FAILED/FAILURE_MESSAGE) for use in pre-/post-scripts
• Updated README to include dependencies.bundler.frozen
• Updated README to include sections on post scripts with on_error flag
• Refactored README to use mostly pure markdown instead of HTML

Other fixes

• Restored functionality to the stack show page for previously deployed tasks
  • There was a change to collection rendering which removed a warning but this broke functionality
  • Clicking links when rendering the generic partial led to 500 errors
  • You could no longer rollback to previous deploys or mark health statuses

[Phillita]

I'm working on the CLA with my org now.

[Phillita]

I have signed the CLA!

[juice928]

👋 Hi, I'm an automated AI code review bot. I ran some checks on this PR and found 2 points that might be worth attention (could be false positives, please use your judgment):

1. The logic for deploy.post might need adjustment to support multiple command steps

   • Location: lib/shipit/deploy_commands.rb:L15-L20
   • Impact: If multiple steps are provided as a list, they might be executed as a single command with arguments instead of sequential tasks.
   • Suggestion: Consider iterating over the deploy_post configuration to ensure each step is initialized as an individual command.

2. The rollback.post configuration seems to expect a single command rather than a list

   • Location: lib/shipit/rollback_commands.rb:L9-L14
   • Impact: Multi-step rollback hooks might not execute correctly because subsequent steps are treated as parameters for the first command.
   • Suggestion: It would be great to apply a similar iteration pattern here to handle multiple rollback steps correctly.

If you find these suggestions disruptive, you can reply "stop" , and I'll automatically skip this repository in the future.