Create static/config.json from template file + ENV if not exist

[muellerst-hg]

Fixes #60

Description

static/config.json can be set either from ENV variables or by mounting the file using a volume. docker-entrypoint.sh takes care of that. Current behavior was that config.json is used as is if the file is mounted , otherwise the file is populated with ENV variables.

In some container environments, mount command is not feasible (e.g. kubernetes 1.27.2 / containerd 1.7.2) and entrypoint.sh fails.

Currently, static/config.json is build into the image. However it just serves as a template, because it requires at least API_BASE_URL to be set. So instead of building an empty static/config.json into the image, rather build the image with config.json.tmpl Then check in docker-entrypoint if config.json file exists. If yes, then just leave it as it is. If not, create the file from config.json.tmpl and populate with ENV variables.

Addressed Issue

fixes #60

Additional Details

Checklist

• I have read and understand the contributing guidelines
• This PR introduces new or alters existing behavior, and I have updated the documentation accordingly

[nscuro]

To support container environments where mount command is not feasible

@muellerst-hg Under what conditions exactly will mount not work? I tried reproducing this in a related issue (#513 (comment)), but failed to do so locally. Any idea what I can do to reproduce this problem?

[muellerst-hg]

@nscuro
kubernetes 1.27.2
containerd 1.7.2
runc 1.1.7

mount works well with docker 24.0.2

[nscuro]

Thanks @muellerst-hg, I was able to reproduce with

minikube start --kubernetes-version v1.27.2 --container-runtime containerd

So it's a Containerd limitation.

We now have two approaches that aim to fix this:

• Your PR (Create static/config.json from template file + ENV if not exist #511): Checks if config.json is writeable to determine if it is mounted
• @Breee's PR (Check /proc/mounts instead of mount #514): Checks /proc/mounts directly instead of using mount

What would be the better approach? One thing that comes to mind for the touch way, is that folks using Docker Compose more often than not do not specify :ro for their volume mounts. In those cases the file will be mounted, but still writeable.

[muellerst-hg]

Good catch regarding :rw volume mounts.

I would prefer a different approach:
Currently the image is build with config.json. However the file just serves as a template, because it requires at least API_BASE_URL to be set - either using a volume mount or by overriding it with docker-entrypoint.

Solution: Build the image with config.json.tmpl instead of config.json. Check in docker-entrypoint if config.json file exists. If yes, then just leave it as it is. If not, create the file from config.json.tmpl and populate with ENV variables.

[nscuro]

Sounds like a sane approach to me. @Breee, WDYT?

[Breee]

Sounds like a sane approach to me. @Breee, WDYT?

Yeah I agree. In addition I think that the frontend should not be broken, if there is no config, i.e. be able to handle an empty API_BASE_URL and inform that it is not configured.

[muellerst-hg]

@nscuro updated the PR branch, PR title the description accordingly. Happy merge!