From cea0739f8bc51989a42ad8795a2fd25f9e9dae54 Mon Sep 17 00:00:00 2001
From: "Kyle D. McCormick" <kyle@axim.org>
Date: Fri, 31 May 2024 11:49:16 -0400
Subject: [PATCH] perf: don't unneccessarily rebuild dev assets

TODO:

* is the pre-assets patch in the right place?
* changelog entry
* more details in commit message
* test with 'tutor local'
---
 tutor/templates/build/openedx/Dockerfile      | 214 +++++++++++-------
 tutor/templates/build/openedx/bin/ln-assets   |  68 ++++++
 .../jobs/init/mounted-directories.sh          |  50 ++--
 3 files changed, 221 insertions(+), 111 deletions(-)
 create mode 100755 tutor/templates/build/openedx/bin/ln-assets

diff --git a/tutor/templates/build/openedx/Dockerfile b/tutor/templates/build/openedx/Dockerfile
index c0a2007f76..e7bb5b0ccc 100644
--- a/tutor/templates/build/openedx/Dockerfile
+++ b/tutor/templates/build/openedx/Dockerfile
@@ -11,6 +11,13 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
 ENV LC_ALL=en_US.UTF-8
 {{ patch("openedx-dockerfile-minimal") }}
 
+ENV PATH=/openedx/edx-platform/node_modules/.bin:/openedx/nodeenv/bin:/openedx/venv/bin:${PATH}
+ENV VIRTUAL_ENV=/openedx/venv/
+ENV XDG_CACHE_HOME=/openedx/.cache
+ENV COMPREHENSIVE_THEME_DIRS=/openedx/themes
+ENV STATIC_ROOT_LMS=/openedx/staticfiles
+ENV STATIC_ROOT_CMS=/openedx/staticfiles/studio
+
 ###### Install python with pyenv in /opt/pyenv and create virtualenv in /openedx/venv
 FROM minimal AS python
 # https://github.com/pyenv/pyenv/wiki/Common-build-problems#prerequisites
@@ -63,6 +70,7 @@ RUN git config --global user.email "tutor@overhang.io" \
 # docker build --build-context edx-platform=/path/to/edx-platform
 FROM scratch AS edx-platform
 COPY --from=code /openedx/edx-platform /
+RUN make clean  # Avoid spurious cache misses by ignoring generated files
 
 {# Create empty layers for all bind-mounted directories #}
 {% for name in iter_mounted_directories(MOUNTS, "openedx") %}
@@ -71,9 +79,6 @@ FROM scratch AS mnt-{{ name }}
 
 ###### Install python requirements in virtualenv
 FROM python AS python-requirements
-ENV PATH=/openedx/venv/bin:${PATH}
-ENV VIRTUAL_ENV=/openedx/venv/
-ENV XDG_CACHE_HOME=/openedx/.cache
 
 RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
@@ -89,8 +94,8 @@ RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
     setuptools==69.1.1 pip==24.0 wheel==0.43.0
 
 # Install base requirements
-RUN --mount=type=bind,from=edx-platform,source=/requirements/edx/base.txt,target=/openedx/edx-platform/requirements/edx/base.txt \
-    --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
+COPY --link --from=edx-platform /requirements/edx/base.txt /openedx/edx-platform/requirements/edx/base.txt
+RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
     pip install -r /openedx/edx-platform/requirements/edx/base.txt
 
 # Install extra requirements
@@ -111,25 +116,80 @@ RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
     pip install '{{ extra_requirements }}'
 {% endfor %}
 
-###### Install nodejs with nodeenv in /openedx/nodeenv
-FROM python AS nodejs-requirements
-ENV PATH=/openedx/nodeenv/bin:/openedx/venv/bin:${PATH}
+###### nodejs with nodeenv in /openedx/nodeenv
+FROM python AS nodejs
 
 # Install nodeenv with the version provided by edx-platform
 # https://github.com/openedx/edx-platform/blob/master/requirements/edx/base.txt
 RUN pip install nodeenv==1.8.0
 RUN nodeenv /openedx/nodeenv --node=18.20.1 --prebuilt
 
-# Install nodejs requirements
+###### nodejs + node requirements
+FROM nodejs AS nodejs-requirements
 ARG NPM_REGISTRY={{ NPM_REGISTRY }}
 WORKDIR /openedx/edx-platform
-RUN --mount=type=bind,from=edx-platform,source=/package.json,target=/openedx/edx-platform/package.json \
-    --mount=type=bind,from=edx-platform,source=/package-lock.json,target=/openedx/edx-platform/package-lock.json \
-    --mount=type=bind,from=edx-platform,source=/scripts/copy-node-modules.sh,target=/openedx/edx-platform/scripts/copy-node-modules.sh \
-    --mount=type=cache,target=/root/.npm,sharing=shared \
+COPY --link --from=edx-platform /package.json package.json
+COPY --link --from=edx-platform /package-lock.json package-lock.json
+COPY --link --from=edx-platform /scripts/copy-node-modules.sh scripts/copy-node-modules.sh
+RUN --mount=type=cache,target=/root/.npm,sharing=shared \
     npm clean-install --no-audit --registry=$NPM_REGISTRY
 
-###### Production image with system and python requirements
+FROM nodejs-requirements AS pre-assets
+{{ patch("openedx-dockerfile-pre-assets") }}
+
+###### Minimal set of source files for webpacking JS into bundles
+# We copy the entire source tree, and then delete everything that isn't relevant.
+FROM pre-assets AS js-sources
+COPY --link --from=edx-platform / .
+RUN find . -type f -a \! \
+    \( -path 'node_modules/*' \
+    -o -path '*/static/*' \
+    -o -path '*/assets/*' \
+    -o -path '*/js/*' \
+    -o -name '*.underscore' \
+    -o -name '*.json' \
+    -o -name '*.js' \
+    -o -name '*.jsx' \
+    -o -name '.babelrc' \
+    \) -delete
+
+###### Intermediate image to capture prod JS build
+FROM pre-assets AS js-production
+COPY --link --from=js-sources /openedx/edx-platform /openedx/edx-platform
+RUN npm run webpack
+
+###### Intermediate image to capture dev JS build
+FROM pre-assets AS js-development
+COPY --link --from=js-sources /openedx/edx-platform /openedx/edx-platform
+RUN npm run webpack-dev
+
+####### Minimal set of requirements and source files for compiling Sass into CSS
+FROM pre-assets AS css-sources
+COPY --link --from=edx-platform /requirements/edx/assets.txt requirements/edx/assets.txt
+RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
+    pip install -r requirements/edx/assets.txt
+COPY --link --from=edx-platform /scripts/compile_sass.py scripts/compile_sass.py
+COPY --link --from=edx-platform /common/static common/static
+COPY --link --from=edx-platform /lms/static/sass lms/static/sass
+COPY --link --from=edx-platform /lms/static/sass/partials lms/static/sass/partials
+COPY --link --from=edx-platform /lms/static/certificates/sass lms/static/certificates/sass
+COPY --link --from=edx-platform /cms/static/sass cms/static/sass
+COPY --link --from=edx-platform /cms/static/sass/partials cms/static/sass/partials
+COPY --link --from=edx-platform /xmodule/assets xmodule/assets
+
+###### Intermediate image to capture prod (compressed) CSS build
+FROM css-sources AS css-production
+RUN npm run compile-sass -- --skip-themes
+COPY --link ./themes/ /openedx/themes
+RUN npm run compile-sass -- --skip-default
+
+###### Intermediate image to capture dev (uncompressed) CSS build
+FROM css-sources AS css-development
+RUN npm run compile-sass-dev -- --skip-themes
+COPY --link ./themes/ /openedx/themes
+RUN npm run compile-sass-dev -- --skip-default
+
+###### Intermediate image shared between final dev and prod images
 FROM minimal AS production
 
 # Install system requirements
@@ -153,30 +213,21 @@ USER ${APP_USER_ID}
 
 # https://hub.docker.com/r/powerman/dockerize/tags
 COPY --link --from=docker.io/powerman/dockerize:0.19.0 /usr/local/bin/dockerize /usr/local/bin/dockerize
+
+# Merge in python requirements and node env from intermediate images
 COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=edx-platform / /openedx/edx-platform
 COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=python /opt/pyenv /opt/pyenv
 COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=python-requirements /openedx/venv /openedx/venv
 COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=python-requirements /mnt /mnt
-COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs-requirements /openedx/nodeenv /openedx/nodeenv
-COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs-requirements /openedx/edx-platform/node_modules /openedx/node_modules
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs /openedx/nodeenv /openedx/nodeenv
 
-# Symlink node_modules such that we can bind-mount the edx-platform repository
-RUN ln -s /openedx/node_modules /openedx/edx-platform/node_modules
-
-ENV PATH=/openedx/venv/bin:./node_modules/.bin:/openedx/nodeenv/bin:${PATH}
-ENV VIRTUAL_ENV=/openedx/venv/
-ENV COMPREHENSIVE_THEME_DIRS=/openedx/themes
-ENV STATIC_ROOT_LMS=/openedx/staticfiles
-ENV STATIC_ROOT_CMS=/openedx/staticfiles/studio
+# Merge JS requirements into /openedx/assets
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs-requirements /openedx/edx-platform/common/static/common/js/vendor /openedx/assets/common/static/common/js/vendor
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs-requirements /openedx/edx-platform/common/static/common/css/vendor /openedx/assets/common/static/common/css/vendor
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=nodejs-requirements /openedx/edx-platform/node_modules /openedx/assets/node_modules
 
 WORKDIR /openedx/edx-platform
 
-{# Install auto-mounted directories as Python packages. #}
-{% for name in iter_mounted_directories(MOUNTS, "openedx") %}
-COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=mnt-{{ name }} / /mnt/{{ name }}
-RUN pip install -e "/mnt/{{ name }}"
-{% endfor %}
-
 # We install edx-platform here because it creates an egg-info folder in the current
 # repo. We need both the source code and the virtualenv to run this command.
 RUN pip install -e .
@@ -191,54 +242,17 @@ ENV REVISION_CFG=/openedx/config/revisions.yml
 COPY --chown=app:app settings/lms/*.py ./lms/envs/tutor/
 COPY --chown=app:app settings/cms/*.py ./cms/envs/tutor/
 
-# Pull latest translations via atlas
-RUN make clean_translations
-RUN ./manage.py lms --settings=tutor.i18n pull_plugin_translations --verbose --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }}
-RUN ./manage.py lms --settings=tutor.i18n pull_xblock_translations --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }}
-RUN atlas pull --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }} \
-    translations/edx-platform/conf/locale:conf/locale \
-    translations/studio-frontend/src/i18n/messages:conf/plugins-locale/studio-frontend
-RUN ./manage.py lms --settings=tutor.i18n compile_xblock_translations
-RUN ./manage.py cms --settings=tutor.i18n compile_xblock_translations
-RUN ./manage.py lms --settings=tutor.i18n compile_plugin_translations
-RUN ./manage.py lms --settings=tutor.i18n compilemessages -v1
-RUN ./manage.py lms --settings=tutor.i18n compilejsi18n
-RUN ./manage.py cms --settings=tutor.i18n compilejsi18n
-
 # Copy scripts
 COPY --chown=app:app ./bin /openedx/bin
 RUN chmod a+x /openedx/bin/*
 ENV PATH=/openedx/bin:${PATH}
 
-{{ patch("openedx-dockerfile-pre-assets") }}
-
-# Build & collect production assets. By default, only assets from the default theme
-# will be processed. This makes the docker image lighter and faster to build.
-RUN npm run postinstall  # Postinstall artifacts are stuck in nodejs-requirements layer. Create them here too.
-RUN npm run compile-sass -- --skip-themes
-RUN npm run webpack
-
-# Now that the default theme is built, build any custom themes
-COPY --chown=app:app ./themes/ /openedx/themes
-RUN npm run compile-sass -- --skip-default
-
-# and finally, collect assets for the production image,
-# de-duping assets with symlinks.
-RUN ./manage.py lms collectstatic --noinput --settings=tutor.assets && \
-    ./manage.py cms collectstatic --noinput --settings=tutor.assets && \
-    # De-duplicate static assets with symlinks \
-    rdfind -makesymlinks true -followsymlinks true /openedx/staticfiles/
+# Create symlinks from /openedx/edx-platform to /openedx/assets. See script definition for details.
+RUN ln-assets /openedx/assets /openedx/edx-platform
 
 # Create a data directory, which might be used (or not)
 RUN mkdir /openedx/data
 
-# If this "canary" file is missing from a container, then that indicates that a
-# local edx-platform was bind-mounted into that container, thus overwriting the
-# canary. This information is useful during edx-platform initialisation.
-RUN echo \
-  "This copy of edx-platform was built into a Docker image." \
-  > bindmount-canary
-
 # service variant is "lms" or "cms"
 ENV SERVICE_VARIANT=lms
 ENV DJANGO_SETTINGS_MODULE=lms.envs.tutor.production
@@ -247,7 +261,7 @@ ENV DJANGO_SETTINGS_MODULE=lms.envs.tutor.production
 
 EXPOSE 8000
 
-###### Intermediate image with dev/test dependencies
+###### Image ready with development packages and uncompressed static assets
 FROM production AS development
 
 # Install useful system requirements (as root)
@@ -266,7 +280,8 @@ RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
 RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared \
     pip install ipdb==0.13.13 ipython==8.24.0
 
-{# Re-install mounted requirements, otherwise they will be superseded by upstream reqs #}
+# Install mounted requirements
+# Must be done after installing dev requirements, so that local reqs supersede pypi reqs
 {% for name in iter_mounted_directories(MOUNTS, "openedx") %}
 COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=mnt-{{ name }} / /mnt/{{ name }}
 RUN pip install -e "/mnt/{{ name }}"
@@ -278,13 +293,6 @@ ENV PYTHONBREAKPOINT=ipdb.set_trace
 # Point unit tests at the MongoDB container
 ENV EDXAPP_TEST_MONGO_HOST=mongodb
 
-# Recompile static assets: in development mode all static assets are stored in edx-platform,
-# and the location of these files is stored in webpack-stats.json. If we don't recompile
-# static assets, then production assets will be served instead.
-RUN rm -r /openedx/staticfiles && \
-    mkdir /openedx/staticfiles && \
-    npm run build-dev
-
 {{ patch("openedx-dev-dockerfile-post-python-requirements") }}
 
 # Default django settings
@@ -292,9 +300,57 @@ ENV DJANGO_SETTINGS_MODULE=lms.envs.tutor.development
 
 CMD ["./manage.py", "$SERVICE_VARIANT", "runserver", "0.0.0.0:8000"]
 
-###### Final image with production cmd
+# Merge dev assets into dev image, placing edx-platform assets in /openedx/assets
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=js-development /openedx/staticfiles /openedx/staticfiles
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=js-development /openedx/edx-platform/common/static/bundles /openedx/assets/common/static/bundles
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-development /openedx/edx-platform/cms/static/css /openedx/assets/cms/static/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-development /openedx/edx-platform/lms/static/css /openedx/assets/lms/static/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-development /openedx/edx-platform/lms/static/certificates/css /openedx/assets/lms/static/certificates/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-development /openedx/themes /openedx/themes
+
+###### Intermediate image with translations pulled from atlas
+FROM production AS translations
+RUN make clean_translations
+RUN ./manage.py lms --settings=tutor.i18n pull_plugin_translations --verbose --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }}
+RUN ./manage.py lms --settings=tutor.i18n pull_xblock_translations --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }}
+RUN atlas pull --repository='{{ ATLAS_REPOSITORY }}' --revision='{{ ATLAS_REVISION }}' {{ ATLAS_OPTIONS }} \
+    translations/edx-platform/conf/locale:conf/locale \
+    translations/studio-frontend/src/i18n/messages:conf/plugins-locale/studio-frontend
+RUN ./manage.py lms --settings=tutor.i18n compile_xblock_translations
+RUN ./manage.py cms --settings=tutor.i18n compile_xblock_translations
+RUN ./manage.py lms --settings=tutor.i18n compile_plugin_translations
+RUN ./manage.py lms --settings=tutor.i18n compilemessages -v1
+RUN ./manage.py lms --settings=tutor.i18n compilejsi18n
+RUN ./manage.py cms --settings=tutor.i18n compilejsi18n
+
+###### Final image with production assets and command
 FROM production AS final
 
+{# Install auto-mounted directories as Python packages. #}
+{% for name in iter_mounted_directories(MOUNTS, "openedx") %}
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=mnt-{{ name }} / /mnt/{{ name }}
+RUN pip install -e "/mnt/{{ name }}"
+{% endfor %}
+
+# Merge prod assets into prod image, placing edx-platform assets in /openedx/assets
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=js-production /openedx/staticfiles /openedx/staticfiles
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=js-production /openedx/edx-platform/common/static/bundles /openedx/assets/common/static/bundles
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-production /openedx/edx-platform/cms/static/css /openedx/assets/cms/static/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-production /openedx/edx-platform/lms/static/css /openedx/assets/lms/static/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-production /openedx/edx-platform/lms/static/certificates/css /openedx/assets/lms/static/certificates/css
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=css-development /openedx/themes /openedx/themes
+
+# Merge translations into prod image
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=translations /openedx/edx-platform/conf/locale conf/locale
+COPY --link --chown=$APP_USER_ID:$APP_USER_ID --from=translations /openedx/edx-platform/conf/plugins-locale conf/plugins-locale
+
+# and finally, collect assets for the production image,
+# de-duping assets with symlinks.
+RUN ./manage.py lms collectstatic --noinput --settings=tutor.assets && \
+    ./manage.py cms collectstatic --noinput --settings=tutor.assets && \
+    # De-duplicate static assets with symlinks \
+    rdfind -makesymlinks true -followsymlinks true /openedx/staticfiles/
+
 # Default amount of uWSGI processes
 ENV UWSGI_WORKERS=2
 
diff --git a/tutor/templates/build/openedx/bin/ln-assets b/tutor/templates/build/openedx/bin/ln-assets
new file mode 100755
index 0000000000..48f0eb8642
--- /dev/null
+++ b/tutor/templates/build/openedx/bin/ln-assets
@@ -0,0 +1,68 @@
+#!/bin/sh
+#
+# Frontend assets need to be generated in the edx-platform repository.
+# However, when a developer bind-mounts edx-platform, it completely overwrites the repo.
+
+# So, the Dockerfile instead generates the assets *outside* of edx-platform
+# where they will not be overwritten by a bind-mount. This script ensures that edx-platform
+# contains symlinks to those assets. This script is run both in the Dockerfile and in lms's
+# init job; that way, the symlinks exist regardless of whether edx-platform is bind-mounted.
+#
+# USAGE:
+# 
+#     ln-assets ASSETS_DIR EDX_PLATFORM_DIR
+#
+# where EDX_PLATFORM_DIR is to contain symlinks to assets in ASSETS_DIR.
+#       ASSETS_DIR must be an absolute directory.
+#
+# ASSET DIRECTORY                   | PURPOSE
+# ----------------------------------+---------------------------------------------
+# node_modules                      | npm packages
+# common/static/common/js/vendor    | npm JS copies, for use by RequireJS
+# common/static/common/css/vendor   | npm CSS copies, for use by RequireJS
+# common/static/bundles             | JS bundles, generated by Webpack
+# cms/static/css                    | Studio CSS, compiled from Sass
+# lms/static/css                    | LMS CSS, compiled from Sass
+# lms/static/certificates/css       | Certificate CSS, compiled from Sass
+
+set -eu
+
+assets="$1"
+edx_platform="$2"
+
+echo "Create static asset symlinks in $edx_platform towards $assets..."
+set -x
+
+cd "$edx_platform" || ( echo "could not cd to $edx_platform" ; exit 1 )
+
+for dir in \
+		node_modules \
+		common/static/common/js/vendor \
+		common/static/common/css/vendor \
+		common/static/bundles \
+		cms/static/css \
+		lms/static/css \
+		lms/static/certificates/css ; do
+
+	# If there isn't a symlink or there's one to the wrong place, then fix it
+	if test "$(readlink -f $dir)" != "$assets/$dir" ; then
+
+		# If there's an existing symlink (to the wrong place), delete it
+		if [ -L $dir ] ; then
+			rm $dir
+
+		# If there's a file or a dir already, back it up
+		elif [ -d $dir ] || [ -f $dir ] ; then
+			mv -f $dir $dir.bak
+		fi
+
+		# Ensure the symlink's parent dir exists
+		mkdir -p "$(dirname "$dir")"
+
+		# Create the correct symlink
+		ln -s "$assets/$dir" $dir
+	fi
+done
+
+set -x
+echo "Done symlinking static assets."
diff --git a/tutor/templates/jobs/init/mounted-directories.sh b/tutor/templates/jobs/init/mounted-directories.sh
index 0f7c615b8b..c3343c69f3 100644
--- a/tutor/templates/jobs/init/mounted-directories.sh
+++ b/tutor/templates/jobs/init/mounted-directories.sh
@@ -1,43 +1,29 @@
 # The initialization job contains various re-install operations needed to be done
 # on mounted directories (edx-platform, /mnt/*xblock, /mnt/<edx-ora, search, enterprise>)
-# 1. /mnt/*
-# Whenever xblocks or other installable packages are mounted, during the image build, they are copied over to container
-# and installed. This results in egg_info generation for the mounted directories. However, the egg_info is not carried
-# over to host. When the containers are launched, the host directories without egg_info are mounted on runtime
-# and disappear from pip list.
-#
-# 2. edx-platform
-# When a new local copy of edx-platform is bind-mounted, certain build
-# artifacts from the openedx image's edx-platform directory are lost.
-# We regenerate them here.
 
+echo "Performing additional setup for bind-mounted directories."
+set -x # Echo out executed lines
+
+cd /openedx/edx-platform || exit 1
 
-for mounted_dir in /mnt/*; do
+# Whenever edx-platform or installable packages (e.g., xblocks) are mounted,
+# during the image build, they are copied over to container and installed. This
+# results in egg_info generation for the mounted directories. However, the
+# egg_info is not carried over to host. When the containers are launched, the
+# host directories without egg_info are mounted on runtime and disappear from
+# pip list. To fix this, we `pip install` edx-platform (".") and every mounted
+# package ("./mnt/*") again, re-generating the egg-infos.
+for mounted_dir in . /mnt/*; do
     if [ -f $mounted_dir/setup.py ] && ! ls $mounted_dir/*.egg-info >/dev/null 2>&1 ; then
-        echo "Unable to locate egg-info in $mounted_dir"
+        echo "Unable to locate egg-info in $mounted_dir -- generating now."
         pip install -e $mounted_dir
     fi
 done
 
-if [ -f /openedx/edx-platform/bindmount-canary ] ; then
-	# If this file exists, then edx-platform has not been bind-mounted,
-	# so no build artifacts need to be regenerated.
-	echo "Using edx-platform from image (not bind-mount)."
-	echo "No extra setup is required."
-	exit
-fi
-
-echo "Performing additional setup for bind-mounted edx-platform."
-set -x # Echo out executed lines
-
-# Regenerate Open_edX.egg-info
-pip install -e .
-
-# Regenerate node_modules
-npm clean-install
-
-# Regenerate static assets.
-npm run build-dev
+# The same problem exists for edx-platform's compiled frontend assets, but recompiling
+# them is very slow. So, instead of re-compiling, we create symlinks to an alternate
+# directory in which we expect them to have been cached (/openedx/assets).
+ln-assets /openedx/assets /openedx/edx-platform
 
 set -x
-echo "Done setting up bind-mounted edx-platform."
+echo "Done setting up bind-mounted directories."