Deprecate prebuild task

[svenefftinge]

We should deprecate the prebuild lifecycle for tasks as it complicates tasks without adding enough value.
I often see users missusing it. E.g. https://github.com/ray-project/ray/blob/56c309416e04a70d874709b9a612ffb482f3f80a/.gitpod.yml

Adding a deprecation warning to the gitpod yml schema as well as removing the documentation would do as a first step.

[shaal]

If prebuild gets deprecated, how would you prepare the workspace (compile, download docker images, etc), before a user starts a workspace?

I used prebuild here -
https://github.com/shaal/ddev-gitpod/blob/main/.gitpod.yml#L8-L11
https://github.com/shaal/mygitpod/blob/projects/.gitpod.yml#L8-L9
https://github.com/drud/ddev/blob/master/.gitpod.yml#L6-L9

I thought the documentation around prebuild was confusing.
Also confusing is that prebuild is a name of a lifecycle and a name of a command.

[svenefftinge]

You would use init which is the task that is executed on prebuilds and not again when starting a prebuilt workspace.

[shaal]

According to the Gitpod documentation, init runs during prebuild, and then run again every time a new workspace is started.

So when we have a command that compiles everything and take a few minutes, the advantage of prebuild is that it runs before the user opens a new workspace, but with init, it will run during prebuild but then users will have to wait for the compile again, once they open a new workspace.

[corneliusludmann]

The init command is executed once only. When you start a workspace that does not have a prebuild, it's executed at workspace start. When you start a workspace that has a prebuild, it does NOT executes init but before and command.

The prebuild command runs during prebuilds only and never when a workspace without prebuild is started. The application is pretty limited.

I hope I have been able to shed some light on this.

[shaal]

Thank you @corneliusludmann for clarifying.
It sounds like init IS the way to go, anywhere I used prebuild before.

Do you know when will this change take effect? and what will happen to workspaces that would still use prebuild?

[corneliusludmann]

For now, we will make the prebuild task deprecated soon and remove it from the docs but still fully support it. However, using init instead of prebuild now in your projects would be a good idea.

[shaal]

👍 Thank you

[svenefftinge]

@shaal since the semantics of init didn't seem to come across in the docs, you may have a good suggestion on how to better explain it?

[rfay]

I'd say that https://www.gitpod.io/docs/config-start-tasks/ should probably be rewritten from scratch; examples with explanations would do the most good probably.

[mikenikles]

Reminders:

• Update the new references/gitpod-yml docs to mark this task as deprecated.
  • Docs updated in https://github.com/gitpod-io/website/pull/616
• Update the Start Tasks docs. A rewrite of the entire page as per above comment will be a separate task.
  • Tracking as https://github.com/gitpod-io/website/issues/617
  • PR with preview URL for the new docs: https://github.com/gitpod-io/website/pull/621