Add pagure investigation document to dist-git investigation

This adds Pagure related investigation to dist git decoupling ARC investigation.

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

docs/dist-git-move/index.rst

@@ -49,6 +49,7 @@ Index
     fedpkg
     hotness
     notifications
+    pagure
     toddlers
     messaging
 

docs/dist-git-move/pagure.rst

@@ -0,0 +1,65 @@
+.. _pagure:
+
+Pagure Dist Git Interactions With Pagure
+====
+
+`Pagure <https://pagure.io/pagure>`_ is the git forge on which dist git is currently
+based on. The dist git is a plugin for Pagure and it shares plenty of functionality with it.
+
+Possible Interactions
+----
+
+There aren't any interactions between Pagure and dist git in Fedora at all, but the
+dist git is running on top of pagure.
+As dist git is a plugin for Pagure, in this investigation only the dist git specific parts
+will be mentioned.
+
+Theme
+^^^^
+
+- The pagure contains the `theme <https://pagure.io/pagure/blob/master/f/pagure/themes/srcfpo>`_
+  for dist git
+
+Backend
+^^^^
+
+- Dist-git is using the `Pagure API <https://pagure.io/pagure/blob/master/f/pagure/api>`_
+  with few added endpoint, which could be recognized by having ``_dg/`` in URL
+- Dist-git is using the same
+  `messaging scheme as pagure <https://github.com/Pagure/pagure-messages>`_
+- Dist-git is using
+  `FAS integration <https://pagure.io/pagure/blob/master/f/pagure/ui/oidc_login.py>`_
+  from Pagure
+- Dist-git is using
+  `ACL implementation <https://pagure.io/pagure/blob/master/f/pagure/lib/git_auth.py>`_
+  from pagure
+
+UI
+^^^^
+
+- Dist-git is using
+  `Option to give repository <https://pagure.io/pagure/blob/master/f/pagure/ui/repo.py#_3171>`_
+  from pagure
+- Issues are just link to bugzilla tracker for the repository in bugzilla dist-git
+- Monitoring status setting (backend implemented in
+  `dist-git <https://pagure.io/pagure-dist-git/blob/master/f/pagure_distgit/plugin.py>`_)
+- Orphaning and taking orphaned projects(backend implemented in
+  `dist-git <https://pagure.io/pagure-dist-git/blob/master/f/pagure_distgit/plugin.py>`_)
+- Links to koji, bodhi, bugzilla, packages and koschei
+
+
+Changes proposed
+----
+
+In order to switch out Pagure Dist Git for an alternative that provides a
+relatively compatible API pattern, the following changes must be made in the
+places mentioned below.
+
+Necessary
+^^^^
+
+- The separate messaging schema needs to be created for dist git
+- API needs to be separated from the pagure API
+- ACL implementation needs to use the new chosen git forge implementation
+- FAS integration needs to be re-implemented
+- The pagure theme needs to be separated from pagure repository