[FEAT] Add envsubst or placeholders to image

[FelixGaebler]

Is your feature request related to a problem? Please describe.
When using the Conduktor CLI to deploy resources (e.g., clusters), the configuration often includes sensitive data such as usernames and passwords. Currently, there is no standard way to safely hide or manage these sensitive values in CI/CD pipelines, which increases the risk of exposing credentials.

Describe the solution you'd like
I would like to have a standard method integrated into the Conduktor CLI for securely handling sensitive information in CI/CD environments. This could include support for tools like envsubst or a built-in placeholder system that securely replaces sensitive data during pipeline execution without exposing it.

Describe alternatives you've considered
I’ve considered using third-party solutions like envsubst to replace environment variables in configuration files, but this requires additional setup and doesn't ensure consistency across pipelines.

[qboileau]

Hi @FelixGaebler

Good news, latest version of the Conduktor CLI (v0.3.1) include environment variable expansion in YAML manifests !

When reading YAML manifests, the Conduktor CLI search for ${ENV} patterns and replace them using found environment variable matching ENV name.
It also supports default values as fallback using POSIX notation ${ENV:-default}.

It fails if environment variable is not found or set empty.
You can avoid a crash and use empty string as default value if with permissive CLI flag.

You have an example test here

Hope this help !

[FelixGaebler]

Thanks alot! Still - you should include this into your documentation! :)

[qboileau]

We missed this in our documentation, it's now fixed https://docs.conduktor.io/platform/reference/cli-reference/#using-environment-variables-for-secrets
Thank you for the reminder.