[BUG?] Access logs for sub-domains are not written after Apr 26 update

[jedi-admin]

Caddy version:

v2.5.1 h1:bAWwslD1jNeCzDa+jDCNwb8M3UJ2tPa8UZFFzPVmGKs=

running as: systemctl start caddy on Ubuntu 20.04.4 LTS

Caddy file:

(logging) {
	log {
		format json {
			message_key msg
			level_key level
			time_key ts
			name_key name
			time_format wall_milli
		}
		output file /var/log/caddy/{args.0}.access.log {
			roll_size 10mb
			roll_keep 20
			roll_keep_for 30d
		}
		level INFO
	}
}

*.domain.com {
	redir https://domain.com{uri}
}

domain.com {
	import logging domain.com
	respond "ok" 200
}

sub1.domain.com {
	import logging sub1.domain.com
	respond "ok" 200
}

sub2.domain.com {
	import logging sub2.domain.com
	respond "ok" 200
}

Expected behavior:

in the folder /var/log/caddy we should see the following files when each sub-domain is accessed:

• domain.com.access.log
• sub1.domain.com.access.log
• sub2.domain.com.access.log

Issue

• Currently there is only one log file created for the root domain; access logs for sub-domains are not created

Tried already:

• replace import logging sub1.domain.com with:

          log {
              output file /var/log/caddy/sub1.domain.com
      }
  

• replacing . with _ in the domain name, e.g. import logging sub1_domain_com
• permissions to access /var/log/caddy are correct

Notes:

prior Apr 26 everything was working fine.

[bt90]

Isn't that the expected behaviour? You catch all subdomain requests in the first block without logging. After the redirect only domain.com would receive requests and therefore yield log entries.

[francislavoie]

Adapting the config to JSON, the issue becomes obvious:

					"logs": {
						"logger_names": {
							"domain.com": "log0",
							"sub1.domain.com": "log1",
							"sub2.domain.com": "log2"
						},
						"skip_hosts": [
							"*.domain.com"
						]
					}

The skip_hosts is preventing the sub1.domain.com loggers from working, I think. We might need to flip this so if there's an explicitly configured logger, wildcard skips should not skip those.

I think this behaviour changed in https://github.com/caddyserver/caddy/pull/4606 which is where skip_hosts started honoring wildcard domains.

[owenconti]

Just wanted to chime in and say that the current behaviour definitely is not intuitive with how the rest of Caddy works. From the docs:

If a request matches multiple site blocks, the site block with the most specific matching address is chosen. Requests don't cascade into to other site blocks.

In my case I have two blocks: www.domain.com and *.domain.com.

• www.domain.com has logging enabled
• *.domain.com reverse proxies to www.domain.com

Because of that setup (and this issue) requests directly to www.domain.com were not being logged.

Flipping the logic like @francislavoie mentioned above would be ideal 👍

[francislavoie]

FYI I opened #5102 the other day which should solve this issue. Please feel free to try it out and confirm!