Make the remaining bash script part of the installer image instead of the KOTS job template.

[mrsimonemms]

Motivation

The installation script of the installer job in KOTS is currently a bash script defined in the K8s job template YAML file. That's hard to maintain, hard to test, makes it rather cumbersome to write that script, and prevents re-using stuff from this script (e.g. for implementing a preflight check that checks the KOTS config. For that reason, the functionality of the bash script should be part of the installer image instead. That allows re-using it in preflight checks and gives this functionality a proper home. Where appropriate, functions should be moved to the Gitpod installer binary and simply called from the bash script.

Objectives

• Improve maintainability. Maintaining a bash script as part of a YAML file is rather cumbersome.
• Moving parts of the functionality to the installer brings type safety and allows better code testing.
• Allow re-using functions.
• Break the functionality into parts so that they can be tested separately. (Currently, the bash script can hardly be tested.)

Tasks

• [x] #12197
• [x] #12259
• [x] #12678
• [x] #12198
• [x] #12199
• [x] #12984
• [x] #12847
• [ ] #12015
• [x] #13114
• [ ] #13151

[csweichel]

Is there a way we could make the shell script go away entirely, and instead make it part of the installer (without incurring a hard KOTS dependency)?

Motivation:

• Go is often easier to maintain than bash
• This might be a path how we can empower the other teams to understand the installation process completely again
• We might learn things that could come in handy should we need to move to away from KOTS

[mrsimonemms]

@csweichel yeah, that's basically the intention

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.