[Feature]: app config setting overwrite

[p0mvn]

Summary

We repeatedly have a use case where it is useful to overwrite config values in a new patch based on a certain value.

However, there is no good UX for doing so.

Here is an example of how we worked around the issue by simply string-matching the config values. It would be nice to have a more intuitive way of achieving this.

Problem Definition

No response

Proposed Feature

• Expose API for overwriting specific app.toml and config.toml values during start command.
• Ensure that comments and general config file structure is preserved
• Ensure that other config values are not overridden with defaults
• Make it generalized and capable of working with many types

[tac0turtle]

Hey this is already possible, when reading the config you would override the value set there with what you expect. It looks like this is meant to hardcode a value. Evmos and other teams do this already

[p0mvn]

Is there documentation on how to do this?

On our v0.47 SDK, I've run into multiple issues. For example, some existing SDK helpers would overwrite and reset other config values.

I spent considerable effort figuring out how to do this using SDK APIs but concluded that custom logic is the most viable path.

It seems that more folks have experienced similar issues.

[julienrbrt]

I believe it is only currently possible at config initialization (f.e. to set chain defaults: https://github.com/cosmos/cosmos-sdk/blob/8f0d5b1/simapp/simd/cmd/config.go).
I don't think there is an easy way / api to update existing values, once the config exists, after a binary upgrade, for instance.

[julienrbrt]

One solution would be to import confix and use one of its command (https://github.com/cosmos/cosmos-sdk/blob/753ac5d/tools/confix/cmd/mutate.go#L21) to update the value. IMHO this would look nicer than osmosis-labs/osmosis#7368.

[tac0turtle]

closing this as there are a few answers, thanks Julien