[OBS] add Open Build Service service-badge (#6993)

* service: add obs service

* service: obs: replaced replaceAll with replace and global regex

* service: obs: added space between class members

* service: obs: support for multiple instances

* service: obs: removed user prefix from auth vars

obs_userName is now called obs_user and obs_userPass is called obs_pass

Co-authored-by: Caleb Cartwright <calebcartwright@users.noreply.github.com>

* service: obs: removed constructor hack in favour of serviceKey

* service: obs: apply suggestions from @calebcartwright

* service: obs: remove unneccesary http status mappings

Co-authored-by: Caleb Cartwright <calebcartwright@users.noreply.github.com>
Co-authored-by: repo-ranger[bot] <39074581+repo-ranger[bot]@users.noreply.github.com>

doc/server-secrets.md

@@ -193,6 +193,21 @@ installation access to private npm packages
 
 [npm token]: https://docs.npmjs.com/getting-started/working_with_tokens
 
+## Open Build Service
+
+- `OBS_USER` (yml: `private.obs_user`)
+- `OBS_PASS` (yml: `private.obs_user`)
+
+Only authenticated users are allowed to access the Open Build Service API.
+Authentication is done by sending a Basic HTTP Authorisation header. A user
+account for the [reference instance](https://build.opensuse.org) is a SUSE
+IdP account, which can be created [here](https://idp-portal.suse.com/univention/self-service/#page=createaccount).
+
+While OBS supports [API tokens](https://openbuildservice.org/help/manuals/obs-user-guide/cha.obs.authorization.token.html#id-1.5.10.16.4),
+they can only be scoped to execute specific actions on a POST request. This
+means however, that an actual account is required to read the build status
+of a package.
+
 ### SymfonyInsight (formerly Sensiolabs)
 
 - `SL_INSIGHT_USER_UUID` (yml: `private.sl_insight_userUuid`)