Clean up Dockerfiles

Use up-to-date nginx
Run builds on the amd64 architecture (This breaks builds on a Pi, but can simply be removed, it was added because it's much faster)
Copy package lockfile into container
Turn some steps into one

.github/workflows/push.yml

@@ -38,14 +38,14 @@ jobs:
         uses: docker/setup-buildx-action@v1
         id: buildx
 
-      - name: Run Docker buildx
+      - name: Build client images
         run: |
                 docker buildx build \
                 --platform linux/amd64,linux/arm64 \
                 --tag ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME-client:$BRANCH \
                 --output "type=registry" ./client/
 
-      - name: Run Docker buildx
+      - name: Build server images
         run: |
                 docker buildx build \
                 --platform linux/amd64,linux/arm64 \

client/Dockerfile

@@ -1,8 +1,8 @@
-FROM node:17-buster-slim as build
+FROM amd64/node:17-buster-slim as build
 
 WORKDIR /app
 
-COPY package.json .
+COPY package.json package-lock.json .
 
 RUN npm install
 
@@ -14,7 +14,7 @@ COPY public ./public
 
 RUN npm run build
 
-FROM nginx:1.17.8@sha256:380eb808e2a3b0dd954f92c1cae2f845e6558a15037efefcabc5b4e03d666d03
+FROM nginx:1.21.6
 
 EXPOSE 80
 

server/Dockerfile

@@ -9,8 +9,7 @@ WORKDIR $APP_HOME
 
 EXPOSE 4000
 
-COPY mix.exs .
-COPY mix.lock .
+COPY mix.exs mix.lock .
 COPY bitcoinex ./bitcoinex
 
 RUN mix do deps.get