CDEs with a Prebuilds feature provides a way to use their workspaces as short-lived/ephemeral environnement on large/complex repositories.

Coder's closest way of achieving something similar is through startup scripts, which is fine for small code base.
But it doesn't works well for large repositories.

As far as I know, there is currently 3 CDEs implementing it:

• Codespaces: https://docs.github.com/en/codespaces/prebuilding-your-codespaces
• Gitpod: https://www.gitpod.io/docs/configure/projects/prebuilds
• Hocus: https://hocus.dev/docs/prebuilds/

It usually works by building the main branches, (let's say the main/master branch)
The "output" is stored and then any users can get a fresh workspace from it.
Prebuilds are linked to the commit hash they have been built with.

Theses fresh workspaces may contain:

• Object / bytecode files, final binaries / artefacts
• Any dependencies such as libraries/modules, container images, etc
• Debug related files -> symbols/map files, etc...
• Indexes/Caches from developer's tools
• ?

From the 3 CDE above, a prebuild may be triggered via:

• push/merge
• Scheduled
• Manual trigger
• On file change (like devcontainer.json)
• Every N commits
• ?

Why Prebuilds are worth to be implemented

The inability of using short lived/ephemeral workspaces on large repos have several impacts :

• Long lived workspaces may drift and result in "works on my machine" issues.
• Context switching takes time (reviewing PR, hotfix an issue, etc)
• ?

Large companies tend to have large and complex repositories.
Implementing it may help them significantly reduce time spent on the two issues above.

Could also:

• Reduce resources consumption peaks (avoiding N builds by N developers when their workspaces starts)
• ?

Implementation ?

All CDEs above currently supports only one isolation model and/or infrastructure.
Coder doesn't make any assumptions on neither of the infra or isolation model.
Which could make it hard for coder to implement such a feature.

What are you thoughts about it ?

Resources:

• https://github.blog/2022-06-15-prebuilding-codespaces-is-generally-available/