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 +90,50 @@ steps:
       branch:
         - master
         - staging
+      event:
+      - push
+
+# pr dry run
+  - name: api-pr
+    image: plugins/docker
+    settings:
+      dockerfile: Containerfile
+      context: .
+    when:
+      event:
+      - pull_request
+
+  - name: frontend-pr
+    image: plugins/docker
+    settings:
+      dockerfile: web/Containerfile
+      context: web
+    when:
+      event:
+      - pull_request
+
+  - name: validator-pr
+    image: plugins/docker
+    settings:
+      dockerfile: validation/Containerfile
+      context: validation
+    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: 1764861f531e7123022bf8a1898445a3cfb279274f4fa44de5b4ea9757e82401
 
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