Add mergify config file (#300)

(cherry picked from commit 7402c82)

.mergify.yml

@@ -0,0 +1,145 @@
+queue_rules:
+  - name: default
+    conditions:
+      - check-success=Test Rego Policies (pull_request)
+      - check-success=Update rules status (pull_request)
+      - check-success=Update rules metadata (pull_request)
+pull_request_rules:
+  - name: self-assign PRs
+    conditions:
+      - -merged
+      - -closed
+      - "#assignee=0"
+    actions:
+      assign:
+        add_users:
+          - "{{ author }}"
+  - name: forward-port patches to main branch
+    conditions:
+      - merged
+      - label=forwardport-main
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "main"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}](backport #{{ number }}) {{ title }}"
+  - name: ask to resolve conflict
+    conditions:
+      - -merged
+      - -closed
+      - conflict
+    actions:
+      comment:
+        message: |
+          This pull request is now in conflicts. Could you fix it? 🙏
+          To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/
+          ```
+          git fetch upstream
+          git checkout -b {{head}} upstream/{{head}}
+          git merge upstream/{{base}}
+          git push upstream {{head}}
+          ```
+  - name: close automated pull requests with bump updates if any conflict
+    conditions:
+      - -merged
+      - -closed
+      - conflict
+      - author=elasticmachine
+      - label=automation
+    actions:
+      close:
+        message: |
+          This pull request has been automatically closed by Mergify.
+          There are some other up-to-date pull requests.
+  - name: automatic approval for mergify pull requests with changes in bump-rules
+    conditions:
+      - author=mergify[bot]
+      - check-success=Test Policies / Test Rego Policies (pull_request)
+      - check-success=Test Policies / Update rules status (pull_request)
+      - check-success=Test Policies / Update rules metadata (pull_request)
+      - label=automation
+      - files~=^\.mergify\.yml$
+      - head~=^add-backport-next.*
+    actions:
+      review:
+        type: APPROVE
+        message: Automatically approving mergify
+  - name: automatic squash and merge with success checks and the files matching the regex ^.mergify.yml is modified.
+    conditions:
+      - check-success=Test Policies / Test Rego Policies (pull_request)
+      - check-success=Test Policies / Update rules status (pull_request)
+      - check-success=Test Policies / Update rules metadata (pull_request)
+      - label=automation
+      - files~=^\.mergify\.yml$
+      - head~=^add-backport-next.*
+      - "#approved-reviews-by>=1"
+    actions:
+      queue:
+        method: squash
+        name: default
+  - name: delete upstream branch with changes on ^.mergify.yml that has been merged or closed
+    conditions:
+      - or:
+          - merged
+          - closed
+      - and:
+          - label=automation
+          - head~=^add-backport-next.*
+          - files~=^\.mergify\.yml$
+    actions:
+      delete_head_branch:
+  - name: notify the backport has not been merged yet
+    conditions:
+      - -merged
+      - -closed
+      - author=mergify[bot]
+      - "#check-success>0"
+      - schedule=Mon-Mon 06:00-10:00[Europe/Paris]
+      - "#assignee>=1"
+    actions:
+      comment:
+        message: |
+          This pull request has not been merged yet. Could you please review and merge it @{{ assignee | join(', @') }}? 🙏
+  - name: notify the backport policy
+    conditions:
+      - -label~=^backport
+      - base=main
+      - -merged
+      - -closed
+    actions:
+      comment:
+        message: |
+          This pull request does not have a backport label. Could you fix it @{{author}}? 🙏
+          To fixup this pull request, you need to add the backport labels for the needed
+          branches, such as:
+          * `backport-v./d./d./d` is the label to automatically backport to the `8./d` branch. `/d` is the digit
+          **NOTE**: `backport-skip` has been added to this pull request.
+      label:
+        add:
+          - backport-skip
+  - name: remove-backport label
+    conditions:
+      - label~=backport-v
+      - -merged
+      - -closed
+    actions:
+      label:
+        remove:
+          - backport-skip
+  - name: backport patches to 8.10 branch
+    conditions:
+      - merged
+      - label=backport-v8.10.0
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "8.10"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}](backport #{{ number }}) {{ title }}"