Move /etc/sonic.cfg to /run/sonic/sonic.cfg

[agowa]

When using this container in docker-compose it is not that easy to bind mount a file into the container. It has a way better user experience when one can just specify a folder. Currently this doesn't work with the default configuration as the sonic.cfg is directly within /etc. By replacing /etc/sonic.cfg with a symlink to /run/sonic/sonic.cfg we can solve this issue and also introducing a breaking change.

[pirate]

Instead of run, how about /etc/sonic/sonic.cfg? I think it's still config, not runtime state, so something under /etc/... makes more sense.

It's common to check $XDG-CONFIG too when checking /etc, but I don't personally need it 🤷‍♂️

• /etc/sonic/sonic.cfg (lowest precedence)
• ~/.config/sonic/sonic.cfg (optional, check for user config which overrides system config)
• ⬇️ environment variables (per-run env vars are highest precedence)

[agowa]

I picked /run/sonic cause the sonic container is kinda stateless and the config was generated upon runtime. However /etc/sonic/sonic.cfg would also work.

I wouldn't recommend ~/.config/sonic/sonic.cfg, or $XDG-CONFIG for a container, they've kinda bad user experience in this context.