Added support for building image based on tag.

.drone.yml

@@ -4,7 +4,7 @@ type: docker
 name: default
 
 steps:
-  - name: docker  
+  - name: build  
     image: plugins/docker
     settings:
       registry: registry.thegibsonhome.net
@@ -13,4 +13,32 @@ steps:
       password:
         from_secret: registry_password
       repo: registry.thegibsonhome.net/protonmail-bridge
-      autotag: true
+      tags:
+        - latest
+trigger:
+  branch:
+    - master
+  event:
+    - push
+
+---
+kind: pipeline
+type: docker
+name: tag
+
+steps:
+  - name: build  
+    image: plugins/docker
+    environment:
+      TAG: ${DRONE_TAG}
+    settings:
+      registry: registry.thegibsonhome.net
+      username:
+        from_secret: registry_username
+      password:
+        from_secret: registry_password
+      repo: registry.thegibsonhome.net/protonmail-bridge
+      tags: ${DRONE_COMMIT}
+trigger:
+  event:
+    - tag

Dockerfile

@@ -8,9 +8,12 @@ RUN apk add --no-cache \
       make \
       musl-dev
 WORKDIR /usr/src
-RUN git clone https://github.com/ProtonMail/proton-bridge.git proton-bridge
-WORKDIR /usr/src/proton-bridge
-RUN make build-nogui
+
+ARG TAG
+RUN git clone https://github.com/ProtonMail/proton-bridge.git proton-bridge \
+    && cd proton-bridge \
+    && if [ -n "$TAG" ]; then git checkout tags/$TAG; fi \
+    && make build-nogui
 
 # Create a container for the ProtonMail Bridge.
 FROM alpine:edge