build css in an intermediate container

.dockerignore

@@ -2,6 +2,4 @@ uploads
 node_modules
 static/dist
 static/.webassets-cache
-*.js
-*.json
 *.md

.gitlab-ci.yml

@@ -36,8 +36,6 @@ tests:debian:
   stage: test
   before_script:
     - apt update
-    - apt install nodejs npm
-    - npm install --global postcss
   script:
   - apt-get -qqy update
   - apt-get -qqy install --no-install-recommends mat2 python3-flask python3-coverage python3-pip python3-setuptools

Dockerfile.production

@@ -1,5 +1,11 @@
+# Build the needed css files in an intermediate container
+FROM node:14-buster AS static_web_assets_build
+WORKDIR /var/www/mat2-web
+COPY . /var/www/mat2-web
+RUN npm install \
+    && npm install --global postcss \
+    && npm run build:css
 # https://github.com/nginxinc/docker-nginx-unprivileged/blob/master/stable/buster/Dockerfile
-
 From debian:buster-slim
 
 LABEL maintainer="Mat-Web Co-Maintainer <jan.friedli@immerda.ch>"
@@ -7,6 +13,7 @@ LABEL maintainer="Mat-Web Co-Maintainer <jan.friedli@immerda.ch>"
 WORKDIR /var/www/mat2-web
 
 COPY . /var/www/mat2-web
+COPY --from=static_web_assets_build /var/www/mat2-web/static/dist ./static/dist
 
 ENV MAT2_WEB_DOWNLOAD_FOLDER /app/upload
 
@@ -38,6 +45,9 @@ RUN set -x \
     && mkdir -p /var/cache/nginx \
     && chown -R 101:0 /var/cache/nginx \
     && chmod -R g+w /var/cache/nginx \
+    && mkdir -p /var/www/mat2-web/static/.webassets-cache \
+    && chown -R 101:0 /var/www/mat2-web/static/.webassets-cache \
+    && chmod -R g+w /var/www/mat2-web/static/.webassets-cache \
     && ln -sf /dev/stdout /var/log/nginx/access.log \
     && ln -sf /dev/stderr /var/log/nginx/error.log \
     && rm -rf /var/cache/apt/* /var/lib/apt/lists/* \

main.py

@@ -23,7 +23,7 @@ def create_app(test_config=None):
 
     # Non JS Frontend
     assets = Environment(app)
-    css = Bundle("src/main.css", output="dist/main.css", filters="postcss")
+    css = Bundle("src/main.css", output="dist/main.css")
     assets.register("css", css)
     css.build()
     app.jinja_loader = jinja2.ChoiceLoader([  # type: ignore