Add a test for docker (#112)

.github/workflows/docker.yml

@@ -0,0 +1,19 @@
+name: Check Docker build
+on: [pull_request]
+jobs:
+  docker:
+    name: Docker
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+
+    - name: Start With Docker
+      run: |
+        docker build . --tag openslides-vote
+        printf "my_token_key" > auth_token_key 
+        printf "my_cookie_key" > auth_cookie_key
+        timeout --preserve-status --signal=SIGINT 5s docker run --network host -v $PWD/auth_token_key:/run/secrets/auth_token_key -v $PWD/auth_cookie_key:/run/secrets/auth_cookie_key openslides-vote
+      env:
+        DOCKER_BUILDKIT: 1

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.18-alpine3.13 as base
+FROM golang:1.18-alpine as base
 WORKDIR /root/
 
 RUN apk add git