Ensure .env files are visible on the build stage, and parse UI env va…

…rs (#434)

Co-authored-by: Peter Wilson <[email protected]>

.dockerignore

@@ -75,6 +75,10 @@ target/
 .venv/
 venv/
 
+# Environment variable files
+# ALLOW .env files
+!.env
+
 # PyCharm
 .idea
 

lumigator/frontend/Dockerfile

@@ -7,6 +7,13 @@ COPY ../../ /mzai
 
 WORKDIR /mzai/
 
+# Copy the .env file for the entire project, and perform some transformation on it.
+# Only env vars starting with the 'VUE_APP_' prefix are made visible by the Vite build system (See: vite.config.js),
+# but we extract only these variables in a kind of 'least privilege' way.
+# See: https://cli.vuejs.org/guide/mode-and-env.html#environment-variables
+COPY .env /mzai/lumigator/frontend/
+RUN cat .env | grep -E ^VUE_APP_ > /mzai/lumigator/frontend/.env
+
 # Install dependencies
 RUN npm --prefix /mzai/lumigator/frontend install
 
@@ -17,7 +24,7 @@ RUN npm --prefix /mzai/lumigator/frontend run build
 FROM nginx:1.27.2-alpine-slim AS server
 
 # Copy built files to the Nginx image
-COPY --from=base  /mzai/lumigator/frontend/dist /usr/share/nginx/html
+COPY --from=base /mzai/lumigator/frontend/dist /usr/share/nginx/html
 
 # Copy a default nginx config, adjusted to support single page applications
 COPY --from=base /mzai/lumigator/frontend/nginx.conf /etc/nginx/conf.d/default.conf