Separate monthly cron and explicit promote

.drone.yml

@@ -29,10 +29,38 @@ name: build and publish
 
 trigger:
     event:
-        - cron
         - promote
     target:
         - production
+
+steps:
+    - name: docker build
+      image: plugins/docker
+      environment:
+          REVISION: ${DRONE_COMMIT_SHA}
+          CREATED: ${DRONE_BUILD_CREATED}
+          SOURCE_URL: ${DRONE_GIT_HTTP_URL}
+      settings:
+          purge: true
+          username:
+              from_secret: dockerhub_user
+          password:
+              from_secret: dockerhub_key
+          repo: varakh/hetzner-storagebox-exporter
+          tags:
+              - latest
+      when:
+          branch:
+              - master
+
+---
+kind: pipeline
+type: docker
+name: monhtly build and publish
+
+trigger:
+    event:
+        - cron
     cron:
         include:
             - monthly
@@ -53,6 +81,7 @@ steps:
           repo: varakh/hetzner-storagebox-exporter
           tags:
               - latest
+              - monthly
       when:
           branch:
               - master