ci: add drone

.drone.yml

@@ -0,0 +1,54 @@
+---
+kind: pipeline
+type: docker
+name: linting
+
+steps:
+  - name: gitleaks
+    image: plugins/gitleaks
+    settings:
+      path: .
+    when:
+      event:
+        exclude:
+          - tag
+
+  - name: hadolint
+    image: hadolint/hadolint:latest-debian
+    commands:
+      - hadolint Dockerfile
+
+---
+kind: pipeline
+type: docker
+name: selfhosted
+depends_on: # bezieht sich auf linting pipeline
+  - linting
+steps:
+  - name: docker_build_and_push_selfhosted
+    image: plugins/docker
+    settings:
+      dockerfile: Dockerfile
+      repo: registry.mgrote.net/postfix
+      registry: registry.mgrote.net
+      tags:
+        - ${DRONE_COMMIT_SHA:0:8}
+        - ${DRONE_COMMIT_BRANCH}
+        - latest
+    when:
+      event:
+        exclude:
+          - pull_request
+          - tag
+
+  - name: docker_build_and_push_selfhosted_tag
+    image: plugins/docker
+    settings:
+      dockerfile: Dockerfile
+      repo: registry.mgrote.net/postfix
+      registry: registry.mgrote.net
+      tags:
+        - ${DRONE_TAG}
+    when:
+      event:
+        - tag