docker: add git describe var to gateway image with front

front/docker/Dockerfile.nginx

@@ -12,6 +12,12 @@ RUN npm install --frozen-lockfile
 COPY . /app
 RUN npm run generate-licenses && npm run build
 
+# Add config.json static file
+ARG OSRD_GIT_DESCRIBE
+ENV OSRD_GIT_DESCRIBE=${OSRD_GIT_DESCRIBE}
+RUN 'echo "{\"OSRD_GIT_DESCRIBE\": \"${OSRD_GIT_DESCRIBE}\"}" > /app/config.json'
+
+
 ### TESTS STAGE
 
 FROM build AS tests
@@ -23,18 +29,11 @@ COPY --from=test_data . /tests/data
 
 FROM nginx:alpine
 
-RUN apk add npm && \
-    npm install -g @import-meta-env/cli && \
-    rm /etc/nginx/conf.d/default.conf
-
 COPY docker/nginx.conf /etc/nginx/conf.d
 COPY docker/nginx-entrypoint.sh /entrypoint.sh
 
 COPY --from=build /app/build /srv
 COPY --from=build /app/.env.example /
 
-ARG OSRD_GIT_DESCRIBE
-ENV OSRD_GIT_DESCRIBE=${OSRD_GIT_DESCRIBE}
-
 ENTRYPOINT ["/entrypoint.sh"]
-CMD ["sh", "-c", "npx import-meta-env -x /.env.example -p /srv/index.html && exec nginx -g 'daemon off;'"]
+CMD ["nginx", "-g", "daemon off"]