Docker image CI build (#43)

Reviewed-on: #43

.drone.yml

@@ -3,7 +3,7 @@
 
 kind: pipeline
 type: docker
-name: app-check
+name: build
 
 steps:
   - name: build-deps
@@ -30,3 +30,23 @@ steps:
           - pull_request
       branch:
         exclude: master
+  - name: build-docker
+    # https://github.com/drone/drone-plugin-index/blob/main/plugins/docker/original.md
+    image: plugins/docker
+    when:
+      branch:
+        - master
+      event:
+        - push
+    settings:
+      username:
+        from_secret: docker_username
+      password:
+        from_secret: docker_token
+      repo:
+        from_secret: docker_repo
+      tags:
+        - latest
+        # https://docs.drone.io/pipeline/environment/reference/
+        - ${DRONE_COMMIT_SHA:0:10}
+        - ${DRONE_TAG}