feat: Find config file with $CHEZMOI_CONFIG

[halostatue]

Closes #2771

This provides an alternative to pure command-line flag configuration when working with multiple source trees.

[halostatue]

This needs further work, especially on documentation and tests. I have yet had no time to consider what testing this might look like.

[twpayne]

I think that the code in this PR will cause the values read from the environment variables to be overwritten with values from the configuration file. I think the hook needs to happen at the end of ./pkg/cmd.Config.readConfig.

[halostatue]

I think that the code in this PR will cause the values read from the environment variables to be overwritten with values from the configuration file. I think the hook needs to happen at the end of ./pkg/cmd.Config.readConfig.

It’s possible — even probable. I think that will require some additional thinking and tracking to identify where the value came from. On the other hand, if most of these values could be found in a configuration file, then the only thing that might be necessary is $CHEZMOI_CONFIG — and the recommendation is that the config file has the necessary configuration to override everything else. This was mostly pushed for the moment to start a code discussion. I’ll look at refining it over the next day or two.

[halostatue]

I’m reworking this so that some of the variable names better match the corresponding command-line flags and configuration (instead of CHEZMOI_CACHE_PATH, it will be CHEZMOI_CACHE_DIR, etc.).

Some inconsistencies as I’m looking through this:

• --persistent-state does not have a corresponding value in the config file.
  • Should persistentState be added to the config file? If not, should we remove $CHEZMOI_PERSISTENT_STATE?
• scriptTempDir does not have a corresponding command-line flag.
  • Should one be added? Should we have $CHEZMOI_SCRIPT_TEMP_DIR?

Since most of the flags are available in the configuration file, I think we should mark the following flags as deprecated and remove them in Chezmoi v3:

• --cache (use cacheDir instead)
• --destination (use destDir instead)
• --persistent-state (add persistentState to configuration file)
• --source (use sourceDir instead)
• --working-tree (use workingTree instead)

With the deprecation of these flags, we can change this to only support $CHEZMOI_CONFIG, which could be used instead of --config.

What do you think @twpayne?

[halostatue]

feat: Find config file with $CHEZMOI_CONFIG

Resolves #2771

When $CHEZMOI_CONFIG to be set, chezmoi will act as if it were called with chezmoi --config $CHEZMOI_CONFIG. If both $CHEZMOI_CONFIG and --config PATH-TO-CONFIG are provided, the command-line flag wins.

doc: Show config vars for global flags

doc: Add JSONC configuration example

doc: Improved information for config vars

[twpayne]

Sorry, I am against this PR.

Currently chezmoi sets a wide range of environment variables for processes that it spawns. All of these variables begin with CHEZMOI.

This PR adds a special environment variable which is the first and only one to be read by chezmoi. This is inconsistent with chezmoi's existing use of environment variables.

I don't like configuration being set via environment variables as they are generally not trivially visible to the user (unlike, say command line arguments). I think the original problem is better solved with a wrapper script or alias.

[halostatue]

OK. Let me see what we can discuss on this:

1. There are some (I think good) improvements to the documentation. Should I open a PR for those (and rework the bits out which refer to $CHEZMOI_CONFIG)?
2. Would you accept a PR for improved wrapper script examples that include a $CHEMOI_CONFIG reader so that such a script can be responsive to direnv configuration?

That latter part is sort of what would be important to me—and why I thought this would be a worthwhile, as I regularly have .envrc files that specify AWS_PROFILE specific to that directory for running terraform, for example. That is, I don’t want a czb wrapper function / script; I just want to remember chezmoi apply.

[twpayne]

• There are some (I think good) improvements to the documentation. Should I open a PR for those (and rework the bits out which refer to $CHEZMOI_CONFIG)?
• Would you accept a PR for improved wrapper script examples that include a $CHEMOI_CONFIG reader so that such a script can be responsive to direnv configuration?

Yes, both would be fantastic, thank you!

[twpayne]

Superseded by #2843.