Disable colors in logs

[stepancheg]

Description

Youki is not meant to be used directly by humans, and colors in output makes reading logs in various tools (eg kubectl logs) unhelpful.

We can additionally do:

• add an option or env var to enable colors
• detect if stderr is tty and enable colors

Not sure it is worth the trouble. E.g. this is error message I currently have:

stderr=\u{1b}[31mERROR\u{1b}[0m \u{1b}[2mlibcontainer::process::init::process\u{1b}[0m\u{1b}[2m:\u{1b}[0m failed to drop capabilities \u{1b}[3merr\u{1b}[0m\u{1b}[2m=\u{1b}[0mSetCaps(CapsError(\"capset failure: Operation not permitted (os error 1)\"))\n\u{1b}[31mERROR\u{1b}[0m \u{1b}[2mlibcontainer::process::container_intermediate_process\u{1b}[0m\u{1b}[2m:\u{1b}[0m failed to initialize container process: failed syscall\n\u{1b}[31mERROR\u{1b}[0m \u{1b}[2mlibcontainer::process::container_main_process\u{1b}[0m\u{1b}[2m:\u{1b}[0m failed to wait for init ready: exec process failed with error error in executing process : failed syscall\n\u{1b}[31mERROR\u{1b}[0m \u{1b}[2mlibcontainer::container::builder_impl\u{1b}[0m\u{1b}[2m:\u{1b}[0m failed to run container process exec process failed with error error in executing process : failed syscall\n\u{1b}[31mERROR\u{1b}[0m \u{1b}[2myouki\u{1b}[0m\u{1b}[2m:\u{1b}[0m error in executing command: failed to create container: exec process failed with error error in executing process : failed syscall\nexec failed : failed to create container: exec process failed with error error in executing process : failed syscall

I will strip ANSI escapes from it, but again, I believe no colors by default is better.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• Test updates
• CI/CD related changes
• Other (please describe):

Testing

• Added new unit tests
• Added new integration tests
• Ran existing test suite
• Tested manually (please provide steps)

cargo run --bin=youki -- exec dfgdfg

colors before, no colors after.

Related Issues

Additional Context

[saku3]

Thank you! LGTM.

PTAL @youki-dev/youki-reviewers

[nayuta723]

I will strip ANSI escapes from it, but again, I believe no colors by default is better.

I agree as well

We can additionally do:

• add an option or env var to enable colors
• detect if stderr is tty and enable colors

If we are going to address this in a separate PR, could you please create an issue and link it to the relevant parts of the code?

[stepancheg]

#3435