Second version of Caddy server introduced incompatibilities with previous version. There is Caddy migration guide. I was following it and changed old proxy config to new reverse_proxy.

Caddy v1 config

example.com {
  tls somebody@example.com
  proxy / 127.0.0.1:2000
  log /var/log/example.log
}

invalid Caddy v2 config

example.com {
  tls somebody@example.com

  reverse_proxy / 127.0.0.1:2000
  log {
    format console
    output file /var/log/example.log
  }
}

But there were strage errors on my page.

I couldn’t fetch favicon:

filename /favicon.ico
Status 502 Bad Gateway

And most of the requests (getting images, javascript files,…) succeeded with returning nothing:

length 0, http status 200

There is another change - reverse_proxy now only proxy given path. So you have to specify, which paths to use. So with /* we proxy everything to our service on port 2000.

correct Caddy v2 config

example.com {
  tls somebody@example.com

  reverse_proxy /* 127.0.0.1:2000
  log {
    format console
    output file /var/log/example.log
  }
}

links

• Caddy migration guide