Add new application swh-loader-metadata

Refs. sysadm-environment#4794

apps/swh-loader-metadata/Dockerfile

+# Deeply inspired from the Dockerfile of the swh-graph project
+FROM python:3.10-bullseye
+
+RUN apt-get -y update && \
+    apt-get -y upgrade && \
+    apt-get install -y libcmph-dev librdkafka-dev && \
+    apt clean && \
+    addgroup --gid 1000 swh && \
+    useradd --gid 1000 --uid 1000 -m -d /opt/swh swh && \
+    mkdir /etc/swh
+
+USER swh
+WORKDIR /opt/swh
+
+COPY --chown=swh:swh requirements-frozen.txt /opt/swh
+COPY --chown=swh:swh entrypoint.sh /opt/swh
+
+ENV PYTHONPATH=/opt/swh
+ENV PATH=/opt/swh/.local/bin:$PATH
+
+RUN chmod u+x /opt/swh/entrypoint.sh && \
+    /usr/local/bin/python -m pip install --upgrade pip && \
+    pip install --no-cache-dir -r requirements-frozen.txt && \
+    pip install gunicorn
+
+ENV SWH_CONFIG_FILENAME=/etc/swh/config.yml
+ENV SWH_WORKER_INSTANCE=loader
+ENV CONCURRENCY=1
+ENV MAX_TASKS_PER_CHILD=1
+ENV LOGLEVEL=INFO
+
+ENTRYPOINT "/opt/swh/entrypoint.sh"

apps/swh-loader-metadata/entrypoint.sh

+#!/bin/bash
+
+if [ -z "${SWH_CONFIG_FILENAME}" ]; then
+  echo "The SWH_CONFIG_FILENAME environment variable must be set"
+  exit 1
+fi
+
+if [ ! -e "${SWH_CONFIG_FILENAME}" ]; then
+  echo "The config file ${SWH_CONFIG_FILENAME} does not exist"
+  exit 1
+fi
+
+echo "Starting loader metadata journal client..."
+exec swh \
+  --log-level $LOGLEVEL \
+  loader metadata \
+  --config-file $SWH_CONFIG_FILENAME \
+  journal-client $SWH_INDEXER_TYPE

apps/swh-loader-metadata/requirements.txt

+swh-loader-metadata