Create a Github Action to ensure variables in shell scripts are set

[owaiskazi19]

Is your feature request related to a problem? Please describe.
Coming from #3106 and #3278 (comment). Create a Github Action to run on pull request to ensure whether shell scripts variables are set.

Describe the solution you'd like
Can use https://github.com/marketplace/actions/shellcheck for the same.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[dblock]

Maybe there's a unit test framework for these shell scripts?

[owaiskazi19]

yamlRestTest takes care of most of the shell scripts during gradle check. GHA will be an added layer to ensure the shell scripts are more secure.

[rursprung]

note that my suggestion was not to create a check just for unset variables.

instead, my suggestion was to create a check which ensures that set -eu -o pipefile (or whatever is the defined standard for OpenSearch) is present in all .sh files.

i do like the ShellCheck action, though, it looks nice!

[minalsha]

@owaiskazi19 any proposed solutions you have that you can document so that someone can pick it up?

[owaiskazi19]

Hey @minalsha! The GHA which can be used to achieve this is in the description.

[laysauchoa]

Hi @owaiskazi19! I am a first time contributor to this project. I'm familiar with GitHub actions, but I am not sure if my PR is correct. Would be possible to guide me a bit on this? I'd love to contribute to the OpenSearch project. Many thanks!

[owaiskazi19]

Hi @owaiskazi19! I am a first time contributor to this project. I'm familiar with GitHub actions, but I am not sure if my PR is correct. Would be possible to guide me a bit on this? I'd love to contribute to the OpenSearch project. Many thanks!

Sure thing @laysauchoa. Welcome to OpenSearch!
We wanted to have strict check for the new scripts which will get added later to the project. The way we handled for OpenSearch repo based on the suggestion by @rursprung (thanks for spending time on it) for the current shell scripts is by having flags set -e -o pipefail.
The Github Action should verify whether the above mentioned flags are present in the script in the PR, and should fail if not. 1. Can you start exploring more on verifying these flags if present in the script?
2. We wanted to have this GHA across all the projects under @opensearch-project.

[minalsha]

HI @laysauchoa , just following up on this issue. Do you need any help contributing to this issue?

[bl1nkker]

Can I take care of this issue? looks like something interesting

[owaiskazi19]

Can I take care of this issue? looks like something interesting

@bl1nkker Sure. I have assigned you the issue and there's a closed PR attached for you to refer. Let us know if you need any additional information. Thanks