Allow user Entrypoint scripts

ci/release-image/Dockerfile

@@ -42,6 +42,11 @@ RUN ARCH="$(dpkg --print-architecture)" && \
 COPY ci/release-image/entrypoint.sh /usr/bin/entrypoint.sh
 RUN --mount=from=packages,src=/tmp,dst=/tmp/packages dpkg -i /tmp/packages/code-server*$(dpkg --print-architecture).deb
 
+# Allow users to have scripts run on container startup to prepare workspace.
+# https://github.com/coder/code-server/issues/5177
+ENV ENTRYPOINTD=${HOME}/entrypoint.d
+RUN mkdir -p ${ENTRYPOINTD}
+
 EXPOSE 8080
 # This way, if someone sets $DOCKER_USER, docker-exec will still work as
 # the uid will remain the same. note: only relevant if -u isn't passed to