Redirect requests show "status 0" instead of 301/307

[ksandrmatveyev]

Moved from https://caddy.community/t/forwardproxy-redirect-requests-show-status-0-instead-of-301-307/25348 as suggested

1. The problem I'm having:

We are using Caddy as a forward proxy with following plugin https://github.com/caddyserver/forwardproxy.

When we call some domain, that redirects to other domain Caddy logs have "status 0":

curl -I https://tableau.com --proxy http://proxy.host.local:3128
HTTP/1.1 200 OK
Server: Caddy
Content-Length: 0

HTTP/1.1 301 Moved Permanently
Server: AkamaiGHost
Content-Length: 0
Location: https://www.tableau.com/
Date: Mon, 26 Aug 2024 16:04:36 GMT
Connection: keep-alive

Invoke-WebRequest -uri https://tableau.com -Proxy http://proxy.host.local:3128

Invoke-RestMethod :
Access Denied
Access Denied

You don't have permission to access "http://tableau.com/" on this server.
Reference #18.c1ec655f.1724687930.59bb8bf
https://errors.edgesuite.net/18.c1ec655f.1724687930.59bb8bf
At line:1 char:2
+ (Invoke-RestMethod -uri https://tableau.com -Proxy http://proxy.host.local ...
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-RestMethod], WebException
    + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand

The question is it possible to see any other "status" in logs like 301/307 (or any other "msg" instead of "handled request") as sometimes it is a bit hard to troubleshoot?

2. Error messages and/or full log output:

Aug 26 15:39:20 proxy.host.local caddy[6184]: {"level":"info","ts":1724686760.250102,"logger":"http.log.access.json","msg":"handled request","request":{"remote_ip":"10.0.100.161","remote_port":"37292","client_ip":"10.0.100.161","proto":"HTTP/1.1","method":"CONNECT","host":"tableau.com:443","uri":"tableau.com:443","headers":{"User-Agent":["curl/7.61.1"],"Proxy-Connection":["Keep-Alive"]}},"bytes_read":0,"user_id":"","duration":0.157647736,"size":4638,"status":0,"resp_headers":{"Server":["Caddy"]}}

Aug 26 16:08:18 proxy.host.local caddy[6184]: {"level":"info","ts":1724688498.070776,"logger":"http.log.access.json","msg":"handled request","request":{"remote_ip":"10.0.109.144","remote_port":"50460","client_ip":"10.0.109.144","proto":"HTTP/1.1","method":"CONNECT","host":"tableau.com:443","uri":"tableau.com:443","headers":{"User-Agent":["Mozilla/5.0 (Windows NT; Windows NT 10.0; en-GB) WindowsPowerShell/5.1.17763.6054"]}},"bytes_read":0,"user_id":"","duration":0.251075173,"size":4579,"status":0,"resp_headers":{"Server":["Caddy"]}}

3. Caddy version:

caddy --version
v2.7.5 h1:HoysvZkLcN2xJExEepaFHK92Qgs7xAiCFydN5x5Hs6Q=

caddy list-modules --versions
http.handlers.forward_proxy v0.0.0-20231105195054-31f01c98cad1

4. How I installed and ran Caddy:

a. System environment:

Operating System: Oracle Linux Server 8.10
Kernel: Linux 5.15.0-3.60.5.1.el8uek.x86_64
Architecture: x86-64

b. Command:

see below

c. Service/unit/compose file:

# cat /etc/systemd/system/caddy.service
[Unit]
Description=Caddy
Documentation=https://caddyserver.com/docs/
After=network.target network-online.target
Requires=network-online.target

[Service]
Type=notify
User=caddy
Group=caddy
ExecStart=/usr/local/bin/caddy run --environ --config /etc/caddy/Caddyfile
ExecReload=/usr/local/bin/caddy reload --config /etc/caddy/Caddyfile --force
TimeoutStopSec=5s
LimitNOFILE=1048576
LimitNPROC=512
PrivateTmp=true
ProtectSystem=full
AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target

# cat /etc/systemd/system/caddy.service.d/overrides.conf

[Service]
RestartPreventExitStatus=1
Restart=on-failure
RestartSec=5s
AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE CAP_SYS_RESOURCE

d. My complete Caddy config:

{
  debug

  admin localhost:2019

  servers :3128 {
    trusted_proxies static 10.0.102.0/25 10.0.102.128/25 10.0.103.0/25
    listener_wrappers {
      proxy_protocol {
        allow 10.0.102.0/25 10.0.102.128/25 10.0.103.0/25
      }
    }
    client_ip_headers X-Forwarded-For
    metrics
  }

  log json {
    output file /var/log/caddy/caddy.log {
      roll_size 100mb
      roll_keep 7
      roll_keep_for 7d
    }
    format json
  }
}

(base) {
  log json

  handle /metrics {
    metrics
  }

  handle /caddy/health-check {
    @goingDown vars {http.shutting_down} true
    respond @goingDown "Bye-bye in {http.time_until_shutdown}" 503
    respond 200
  }
}

:3128 {

  import base

  @group1 client_ip 10.0.104.0/21 10.0.96.0/21
  route @group1 {
    forward_proxy {
      hide_ip
      hide_via
      acl {
        allow *.eu-central-1.amazonaws.com
        allow *.eu-west-1.amazonaws.com # https://s3.eu-west-1.amazonaws.com redirects to https://aws.amazon.com/s3/ on non-allowed GET
        allow *.s3-eu-west-1.amazonaws.com
        allow *.s3-eu-central-1.amazonaws.com
        allow s3.amazonaws.com
        allow iam.amazonaws.com
        allow ec2.amazonaws.com
        allow tableau.com # redirects to https://www.tableau.com
        deny all
      }
    }
  }

  route {
    forward_proxy {
      acl {
        deny all
      }
    }
  }

}

import /etc/caddy/conf.d/*

5. Links to relevant resources:

https://caddy.community/t/http-status-code-0-in-caddy-logs-for-a-reverse-proxy-with-template/18685 has some explanation:

Status code 0 is the same as an HTTP 200 status response. It usually happens when the request goes unhandled by Caddy (as in no configured routes wrote a response).