HTTP_AUTH - Allow auth for multiple subdomains

[Kevin-Molina]

Right now, the HTTP_AUTH environment variable can be used to provide authentication.

At present, it is of the form:
basic:<HOST>:<USER>:<TOKEN>

Reference:

apko/pkg/apk/auth/auth.go

Lines 68 to 75 in 70d6b1a

	env := os.Getenv("HTTP_AUTH")
	parts := strings.Split(env, ":")
	if len(parts) != 4 || parts[0] != "basic" {
	return nil
	}
	if req.URL.Host == parts[1] {
	req.SetBasicAuth(parts[2], parts[3])
	}

Since the check is a straight equality check against the full host value, I cannot pull from both of these host values with auth at the same time:

• aaa.domain.com
• bbb.domain.com

I'd like to be able to support pulling with auth from multiple subdomains under a given domain.
I'm also happy to contribute this, but wanted to ask for input / get a green light.

Thanks!