Added caddy web-server recipe

web-server/caddy/Caddyfile

+https://gitlab.example.com {
+    log git.access.log {
+        rotate
+    }
+
+    errors {
+        log git.errors.log
+        404 /opt/gitlab/embedded/service/gitlab-rails/public/404.html
+        422 /opt/gitlab/embedded/service/gitlab-rails/public/422.html
+        500 /opt/gitlab/embedded/service/gitlab-rails/public/500.html
+        502 /opt/gitlab/embedded/service/gitlab-rails/public/502.html
+    }
+
+    proxy / http://127.0.0.1:8181 {
+        fail_timeout 300s
+
+        proxy_header Host {host}
+        proxy_header X-Real-IP {remote}
+        proxy_header X-Forwarded-Proto {scheme}
+        proxy_header X-Forwarded-Ssl on
+    }
+}

web-server/caddy/README.md

+# Caddy
+
+This is an example configuration of how to use GitLab with [caddy](https://caddyserver.com/).
+
+### Updating GitLab Configuration
+
+Open `/etc/gitlab/gitlab.rb` using your favourite text editor and update the following values.
+
+* Change `external_url` to the https protocol
+* Change `gitlab_workhorse['listen_network']` from `"unix"` to `"tcp"`
+* Change `gitlab_workhorse['listen_addr']` from `"000"` to `"127.0.0.1:8181"`
+* Add whatever user caddy runs under to `web_server['external_users']` unless root
+* Change `nginx['enable'] = "true"` to `nginx['enable'] = "false"`
+* Save and exit the configuration file and run `gitlab-ctl reconfigure` to update gitlabs configuration
+
+### Updating the Caddyfile
+
+Simply change gitlab.example.com to point to your FQDN.