ci: use mergify to add labels to PRs

Adding labels to Pull-Requests can be done by Mergify. It is very useful
to filter PRs on their labels so that experts in certain areas can
identify PRs to review.

Adding labels is currently a complete manual process, this adds some
automation for it. There is no intention of it being complete, this is
mostly for getting started and trying things out.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

.mergify.yml

@@ -297,3 +297,70 @@ pull_request_rules:
       merge: {}
       dismiss_reviews: {}
       delete_head_branch: {}
+  ##
+  ## Automatically set/remove labels
+  ##
+  - name: title contains DNM
+    conditions:
+      - title~=DNM
+    actions:
+      label:
+        add:
+          - DNM
+  - name: title contains CephFS
+    conditions:
+      - "title~=cephfs: "
+    actions:
+      label:
+        add:
+          - component/cephfs
+  - name: title contains RBD
+    conditions:
+      - "title~=rbd: "
+    actions:
+      label:
+        add:
+          - component/rbd
+  - name: title contains CI or testing
+    conditions:
+      - "title~=(ci)|(testing): "
+    actions:
+      label:
+        add:
+          - component/testing
+  - name: title contains Helm
+    conditions:
+      - title~=helm
+    actions:
+      label:
+        add:
+          - component/deployment
+  - name: title contains rebase
+    conditions:
+      - "title~=rebase: "
+    actions:
+      label:
+        add:
+          - rebase
+  - name: title indicates a bug fix
+    conditions:
+      - title~=(bug)|(fix)
+    actions:
+      label:
+        add:
+          - bug
+  - name: title contains cleanup
+    conditions:
+      - "title~=cleanup: "
+    actions:
+      label:
+        add:
+          - cleanup
+  - name: title contains doc
+    conditions:
+      - "title~=doc: "
+    actions:
+      label:
+        add:
+          - component/docs
+          - ci/skip/e2e