Is it possible to read environment variables from yaml configuration files?

[spacewander]

Discussed in #5222

^{Originally posted by abbluiz October 13, 2021}
I want to use different configuration depending on my environment on some YAML configuration files, specially in conf/apisix.yaml in stand-alone mode. Is it possible to read from environment variable like ${VAR} inside YAML file?

[jagerzhang]

At present, we use Python jinja2 to render config.yaml, then we can indirectly set APISIX through environment variables.
If environment variables are naturally supported, i think it is more convenient.

[abbluiz]

Is it enough to call the function resolve_conf_var() with the 2 variables below (from file apisix/apisix/core/config_yaml.lua lines 103-104)?

apisix_yaml = apisix_yaml_new
apisix_yaml_ctime = last_change_time

Like that:

local ok, err = resolve_conf_var(apisix_yaml)
if not ok then
    return nil, err
end

local ok, err = resolve_conf_var(apisix_yaml_ctime)
if not ok then
    return nil, err
end

[spacewander]

You can try it.

[wilson-1024]

I want to try to implement this function, can it be assigned to me?