feat: add commit hash to image tag

.drone.yaml

@@ -3,18 +3,17 @@ type: docker
 
 name: build-and-push-container
 
+triggers:
+  branch:
+    - main
+  event:
+    - push
+
 steps:
   - name: build
-    image: docker:20
+    image: plugins/docker
     commands:
-      - COMMIT_HASH=$(git rev-parse --short HEAD)
-      - IMAGE_TAG=gitea.t000-n.de/t.behrendt/backupsidecar:$COMMIT_HASH
-      - docker build -t $IMAGE_TAG .
-    when:
-      event:
-        - push
-      ref:
-        - refs/heads/main
+      - docker build -t gitea.t000-n.de/t.behrendt/backupsidecar:${DRONE_COMMIT:0:8} .
 
   - name: push
     image: plugins/docker
@@ -26,9 +25,4 @@ steps:
       repo: gitea.t000-n.de/t.behrendt/backupsidecar
       tags: 
         - latest
-        - $COMMIT_HASH
-    when:
-      event:
-        - push
-      ref:
-        - refs/heads/main
+        - ${DRONE_COMMIT:0:8}