chore: Run uvicorn as appuser via s6-init.

Make sure it can write logs. Add netcat, so we can bodge a health check.

Refs: OPS-10771

docker/Dockerfile

@@ -1,11 +1,19 @@
 # Build the code.
 FROM python:3.12 AS builder
 
+ENV S6VERSION=2.2.0.3
+
 # Copy only the files necessary to build the code (see .dockerignore in root).
 COPY . /srv/www
 
+# Fetch s6 init files, needed later.
+RUN apt-get clean && apt-get update && apt-get -y install ca-certificates curl && \
+    S6ARCH=$(uname -m | sed 's/x86_64/amd64/') && \
+    echo "Installing s6 version: $S6VERSION for $S6ARCH" && \
+    curl -o /tmp/s6-overlay.tar.gz -jkSL https://github.com/just-containers/s6-overlay/releases/download/v${S6VERSION}/s6-overlay-${S6ARCH}.tar.gz
+
 # Install dependencies. This will be in the `/root/.local` dir by default.
-RUN pip install --upgrade pip setuptools wheel && \
+RUN pip install --root-user-action=ignore --upgrade pip setuptools wheel && \
     python -m venv /opt/venv && \
     /opt/venv/bin/pip install -r /srv/www/html/requirements.txt
 
@@ -20,8 +28,7 @@ ARG GITHUB_REPOSITORY
 ARG GITHUB_SHA
 ARG GITHUB_REF
 
-ENV NGINX_SERVERNAME=ocha-ai-helper.test \
-    GIT_BLAME=$GITHUB_ACTOR \
+ENV GIT_BLAME=$GITHUB_ACTOR \
     GIT_REPO=$GITHUB_REPOSITORY \
     GIT_SHA=$GITHUB_SHA \
     GIT_REF=$GITHUB_REF \
@@ -34,17 +41,34 @@ LABEL info.humanitarianresponse.build.date=$BUILD_DATE \
 # Copy the installed python packages from the builder step.
 COPY --from=builder /opt/venv /opt/venv
 
+# For the init service.
+COPY --from=builder /tmp/s6-overlay.tar.gz /tmp/
+COPY --from=builder /srv/www/docker/etc/services/run_uvicorn /tmp/
+
 # Set environment variables to use the virtual environment.
 ENV PATH=/opt/venv/bin:$PATH
 
-# Download space models.
-RUN mkdir -p /var/log/uvicorn /opt/models  && \
-  python3 -m spacy download en_core_web_sm && \
-  python3 -m spacy download es_core_news_sm && \
-  python3 -m spacy download fr_core_news_sm
+RUN \
+    apt-get clean && apt-get update && apt-get -y install netcat-openbsd procps && \
+    tar xzf /tmp/s6-overlay.tar.gz -C / && \
+    rm -f tar xzf /tmp/s6-overlay.tar.gz && \
+    # Add some users.
+    addgroup --system --gid 4000 appuser && \
+    adduser --system --uid 4000 --gid 4000 --shell /sbin/nologin --comment 'Docker App User' --home /home/appuser --no-create-home appuser && \
+    addgroup --system --gid 508 jenkins && \
+    adduser --system --uid 508 --gid 508 --shell /sbin/nologin --comment 'Jenkins User' --home /var/lib/jenkins --no-create-home jenkins && \
+    mkdir -p /etc/services.d/uvicorn /var/log/uvicorn /opt/models  && \
+    mv /tmp/run_uvicorn /etc/services.d/uvicorn/run && \
+    chown -R appuser:appuser /var/log/uvicorn /opt/models && \
+    # Download space models.
+    python3 -m spacy download en_core_web_sm && \
+    python3 -m spacy download es_core_news_sm && \
+    python3 -m spacy download fr_core_news_sm
 
 COPY --from=builder /srv/www/html /srv/www/html
 
 WORKDIR /srv/www/html
 
-CMD ["/srv/www/html/server.sh"]
+ENTRYPOINT ["/init"]
+
+EXPOSE 8000

docker/etc/services/run_uvicorn

@@ -0,0 +1,12 @@
+#!/usr/bin/with-contenv sh
+set -e
+
+HOME=/srv/www/html
+
+cd /srv/www/html
+
+exec s6-setuidgid appuser uvicorn app:app \
+  --host ${SERVER_HOST:-0.0.0.0} \
+  --port ${SERVER_PORT:-8000} \
+  --log-config=log_config.yaml \
+  --reload