add backport github action (#60)

.backportrc.json

@@ -0,0 +1,14 @@
+{
+  "repoOwner": "spectrocloud",
+  "repoName": "CanvOS",
+  "editor": "code",
+
+  "targetBranchChoices": ["master", "rc-4.0", "release-3.4"],
+
+  "autoMerge": false,
+  "autoMergeMethod": "squash",
+  "commitConflicts": true,
+  "branchLabelMapping": {
+    "^backport-(.+)$": "$1"
+  }
+}

.github/workflows/backport.yaml

@@ -0,0 +1,32 @@
+name: Backport
+
+on:
+  pull_request_target:
+    types: ["labeled", "closed"]
+
+jobs:
+  backport:
+    name: Backport PR
+    runs-on: ubuntu-latest
+    if: |
+      github.event.pull_request.merged == true
+      && contains(github.event.pull_request.labels.*.name, 'auto-backport')
+      && (
+        (github.event.action == 'labeled' && github.event.label.name == 'auto-backport')
+        || (github.event.action == 'closed')
+      )
+    steps:
+      - name: Backport Action
+        uses: sqren/[email protected]
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          auto_backport_label_prefix: backport-
+          add_original_reviewers: true
+
+      - name: Info log
+        if: ${{ success() }}
+        run: cat ~/.backport/backport.info.log
+
+      - name: Debug log
+        if: ${{ failure() }}
+        run: cat ~/.backport/backport.debug.log