Fix gitlab-shell not handling relative URLs over UNIX socketssh-fix-unix-relative-url-access

From
https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/4498#note_397401883,
if you specify a relative path such as:

```
external_url 'http://gitlab.example.com/gitlab'
```

gitlab-shell doesn't have a way to pass the `/gitlab` to the host. For example, let's say we have:

```
gitlab_url: "http+unix://%2Fvar%2Fopt%2Fgitlab%2Fgitlab-workhorse%2Fsocket"
```

If we have `/gitlab` as the relative path, how do we specify what is the
UNIX socket path and what is the relative path? If we specify:

```
gitlab_url: "http+unix:///var/opt/gitlab/gitlab-workhorse.socket/gitlab
```

This is ambiguous. Is the socket in
`/var/opt/gitlab/gitlab-workhorse.socket/gitlab` or in
`/var/opt/gitlab/gitlab-workhorse.socket`?

To fix this, this merge request adds an optional
`gitlab_relative_url_root` config parameter:

```
gitlab_url: "http+unix://%2Fvar%2Fopt%2Fgitlab%2Fgitlab-workhorse%2Fsocket"
gitlab_relative_url_root: /gitlab
```

This is only used with UNIX domain sockets to disambiguate the socket
and base URL path. If `gitlab_url` uses `http://` or `https://`, then
`gitlab_relative_url_root` is ignored.

Relates to https://gitlab.com/gitlab-org/gitlab-shell/-/issues/476

1 files changed, 4 insertions, 0 deletions

diff --git a/config.yml.example b/config.yml.example
index 60435a3..6689ca8 100644
--- a/config.yml.example
+++ b/config.yml.example
@@ -15,6 +15,10 @@ user: git
 # "http+unix://%2Fpath%2Fto%2Fsocket"
 gitlab_url: "http+unix://%2Fhome%2Fgit%2Fgitlab%2Ftmp%2Fsockets%2Fgitlab-workhorse.socket"
 
+# When a http+unix:// is used in gitlab_url, this is the relative URL root to GitLab.
+# Not used if gitlab_url is http:// or https://.
+# gitlab_relative_url_root: "/"
+
 # See installation.md#using-https for additional HTTPS configuration details.
 http_settings:
 #  read_timeout: 300