fix: Move copying translation files before npm run build in Docker (#30099)

Dockerfile

@@ -26,6 +26,10 @@ FROM --platform=${BUILDPLATFORM} node:20-bullseye-slim AS superset-node
 
 ARG NPM_BUILD_CMD="build"
 
+# Include translations in the final build. The default supports en only to
+# reduce complexity and weight for those only using en
+ARG BUILD_TRANSLATIONS="false"
+
 # Used by docker-compose to skip the frontend build,
 # in dev we mount the repo and build the frontend inside docker
 ARG DEV_MODE="false"
@@ -51,7 +55,7 @@ RUN --mount=type=bind,target=/frontend-mem-nag.sh,src=./docker/frontend-mem-nag.
 
 WORKDIR /app/superset-frontend
 # Creating empty folders to avoid errors when running COPY later on
-RUN mkdir -p /app/superset/static/assets && mkdir -p /app/superset/translations
+RUN mkdir -p /app/superset/static/assets
 RUN --mount=type=bind,target=./package.json,src=./superset-frontend/package.json \
     --mount=type=bind,target=./package-lock.json,src=./superset-frontend/package-lock.json \
     if [ "$DEV_MODE" = "false" ]; then \
@@ -62,20 +66,21 @@ RUN --mount=type=bind,target=./package.json,src=./superset-frontend/package.json
 
 # Runs the webpack build process
 COPY superset-frontend /app/superset-frontend
+# This copies the .po files needed for translation
+RUN mkdir -p /app/superset/translations
+COPY superset/translations /app/superset/translations
 RUN if [ "$DEV_MODE" = "false" ]; then \
-        npm run ${BUILD_CMD}; \
+        BUILD_TRANSLATIONS=$BUILD_TRANSLATIONS npm run ${BUILD_CMD}; \
     else \
         echo "Skipping 'npm run ${BUILD_CMD}' in dev mode"; \
     fi
 
-# This copies the .po files needed for translation
-RUN mkdir -p /app/superset/translations
-COPY superset/translations /app/superset/translations
+
 # Compiles .json files from the .po files, then deletes the .po files
-RUN if [ "$DEV_MODE" = "false" ]; then \
+RUN if [ "$BUILD_TRANSLATIONS" = "true" ]; then \
         npm run build-translation; \
     else \
-        echo "Skipping translations in dev mode"; \
+        echo "Skipping translations as requested by build flag"; \
     fi
 RUN rm /app/superset/translations/*/LC_MESSAGES/*.po
 RUN rm /app/superset/translations/messages.pot
@@ -85,6 +90,10 @@ RUN rm /app/superset/translations/messages.pot
 ######################################################################
 FROM python:${PY_VER} AS lean
 
+# Include translations in the final build. The default supports en only to
+# reduce complexity and weight for those only using en
+ARG BUILD_TRANSLATIONS="false"
+
 WORKDIR /app
 ENV LANG=C.UTF-8 \
     LC_ALL=C.UTF-8 \
@@ -132,10 +141,14 @@ COPY --chown=superset:superset --from=superset-node /app/superset/translations s
 
 # Compile translations for the backend - this generates .mo files, then deletes the .po files
 COPY ./scripts/translations/generate_mo_files.sh ./scripts/translations/
-RUN ./scripts/translations/generate_mo_files.sh \
-    && chown -R superset:superset superset/translations \
-    && rm superset/translations/messages.pot \
-    && rm superset/translations/*/LC_MESSAGES/*.po
+RUN if [ "$BUILD_TRANSLATIONS" = "true" ]; then \
+        ./scripts/translations/generate_mo_files.sh \
+        && chown -R superset:superset superset/translations \
+        && rm superset/translations/messages.pot \
+        && rm superset/translations/*/LC_MESSAGES/*.po; \
+    else \
+        echo "Skipping translations as requested by build flag"; \
+    fi
 
 COPY --chmod=755 ./docker/run-server.sh /usr/bin/
 USER superset

docs/docs/installation/docker-builds.mdx

@@ -67,6 +67,10 @@ script and the [docker.yml](https://github.com/apache/superset/blob/master/.gith
 GitHub action.
 
 ## Key ARGs in Dockerfile
+- `BUILD_TRANSLATIONS`: whether to build the translations into the image. For the
+  frontend build this tells webpack to strip out all locales other than `en` from
+  the `moment-timezone` library. For the backendthis skips compiling the
+  `*.po` translation files
 - `DEV_MODE`: whether to skip the frontend build, this is used by our `docker-compose` dev setup
   where we mount the local volume and build using `webpack` in `--watch` mode, meaning as you
   alter the code in the local file system, webpack, from within a docker image used for this

superset-frontend/webpack.config.js

@@ -45,10 +45,10 @@ const ROOT_DIR = path.resolve(__dirname, '..');
 const TRANSLATIONS_DIR = path.resolve(__dirname, '../superset/translations');
 
 const getAvailableTranslationCodes = () => {
-  const LOCALE_CODE_MAPPING = {
-    zh: 'zh-cn',
-  };
-  try {
+  if (process.env.BUILD_TRANSLATIONS === 'true') {
+    const LOCALE_CODE_MAPPING = {
+      zh: 'zh-cn',
+    };
     const files = fs.readdirSync(TRANSLATIONS_DIR);
     return files
       .filter(file =>
@@ -57,10 +57,9 @@ const getAvailableTranslationCodes = () => {
       .filter(dirName => !dirName.startsWith('__'))
       .map(dirName => dirName.replace('_', '-'))
       .map(dirName => LOCALE_CODE_MAPPING[dirName] || dirName);
-  } catch (err) {
-    console.error('Error reading the directory:', err);
-    return [];
   }
+  // Indicates to the MomentLocalesPlugin that we only want to keep 'en'.
+  return [];
 };
 
 const {