drone: do not attempt to deploy pull requests

.drone.yml

@@ -25,6 +25,8 @@ steps:
       branch:
         - master
         - staging
+      event:
+        - push
 
   - name: frontend
     image: plugins/docker
@@ -44,6 +46,8 @@ steps:
       branch:
         - master
         - staging
+      event:
+        - push
 
   - name: validator
     image: plugins/docker
@@ -63,6 +67,8 @@ steps:
       branch:
         - master
         - staging
+      event:
+        - push
 
   - name: deploy
     image: argoproj/argocd:latest
@@ -84,8 +90,65 @@ steps:
       branch:
         - master
         - staging
+      event:
+        - push
+
+# pr dry run
+  - name: api-pr
+    image: plugins/docker
+    settings:
+      registry: registry.itzana.me
+      tags:
+        - ${DRONE_BRANCH}-${DRONE_BUILD_NUMBER}
+        - ${DRONE_BRANCH}
+      dockerfile: Containerfile
+      context: .
+      dry_run: true
+    when:
+      event:
+        - pull_request
+
+  - name: frontend-pr
+    image: plugins/docker
+    settings:
+      registry: registry.itzana.me
+      tags:
+        - ${DRONE_BRANCH}-${DRONE_BUILD_NUMBER}
+        - ${DRONE_BRANCH}
+      dockerfile: web/Containerfile
+      context: web
+      dry_run: true
+    when:
+      event:
+      - pull_request
+
+  - name: validator-pr
+    image: plugins/docker
+    settings:
+      registry: registry.itzana.me
+      tags:
+        - ${DRONE_BRANCH}-${DRONE_BUILD_NUMBER}
+        - ${DRONE_BRANCH}
+      dockerfile: validation/Containerfile
+      context: validation
+      dry_run: true
+    when:
+      event:
+        - pull_request
+
+  - name: build-pr
+    image: alpine
+    commands:
+      - echo "Success!"
+    depends_on:
+      - api-pr
+      - frontend-pr
+      - validator-pr
+    when:
+      event:
+        - pull_request
 ---
 kind: signature
-hmac: 1162b329a9cad12b4c5db0ccf8b8998072b0de9279326f76a493fd0af6794095
+hmac: de6ca0165b6f0dc12828d1665be1646b591887735562714781401f276395f72c
 
 ...