Hi @Unknwon, the error Caddy has output:
This is because there is no transparent preset for v2’s reverse_proxy directive.
For any headers your upstream requires, you will need to add them manually with the header_up subdirective.
Edit: This thread is from early in Caddy 2’s beta cycle, before it was even released. Caddy 2’s default behavior is to pass all headers through to the backend without modification, including setting/augmenting the X-Forwarded-For header for you. Basically, in Caddy 2, “transparent” is the default mode of operation. You do not need to set the headers like you did in v1 unless your backend app has specific/unconventional requirements.
References: