How can I specify DNS Resolver as environment variable or command line argument

[directentis1]

*Describe the feature you'd like
As the title, because cloudflared uses go dns resolver, it looks for /etc/resolv.conf (for linux binaries) when try to resolve domains - which not the case on Android systems.

If it doen't find that file, it sets the default name server to localhost:53
https://github.com/golang/go/blob/e335a2665f5e322a7da8baa22fe816b6ef9aaf24/src/net/dnsconfig.go#L14

Which cause problems as here:

There's a few possible solutions:

• On rooted Android phone, we could just create the /etc/resolv.conf file
• Another way is to add a static entry to /etc/hosts for our domainns
• Building a non-staticly linked version cloudflared. If we build a binary linked to libc it will use that to do name resolution which will probably fix this issue.

The first two require the device/emulator to be rooted.
The third one is too annoying because cloudflared is constantly updated, and adding a release build/fork for this is waste time.

Describe alternatives you've considered
Are there any alternatives to solving this problem? If so, what was your experience with them?
I think environment variable or command line argument is the best way in a scripting context.