feat: ability to disable internal tugtainer-agent (#83)

+ added env var AGENT_ENABLED that can be used to disable internal
tugtainer-agent in main image
+ added entrypoint script

Closes #45

Author: Quenary

.env.example

@@ -6,6 +6,10 @@
 # Possible values: critical, error, warning, info, debug, trace.
 # Default is warning
 LOG_LEVEL=
+# This variable can be used to disable internal tugtainer-agent,
+# for instance, if you cannot use docker.sock on this host, but want to monitor other remote hosts
+# Default is true (agent enabled)
+AGENT_ENABLED=
 # Secret for backend-agent requests signature.
 # Better to set it if agent is on the other network.
 # Default is empty, because agent is used internally in the main image.

Dockerfile.app

@@ -42,6 +42,10 @@ ENV PATH="/app/.venv/bin:$PATH"
 COPY nginx.conf /etc/nginx/nginx.conf
 COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
 
+# Entrypoint script
+COPY entrypoint.sh /app/entrypoint.sh
+RUN chmod +x /app/entrypoint.sh
+
 # Environment
 COPY .env* /app/
 RUN echo "$VERSION" > /app/version
@@ -54,4 +58,4 @@ EXPOSE 80
 HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
   CMD curl -f http://localhost:8000/api/public/health || exit 1
 
-ENTRYPOINT ["/usr/bin/supervisord", "-c", "/etc/supervisor/conf.d/supervisord.conf"]
+ENTRYPOINT ["/app/entrypoint.sh"]

entrypoint.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+AGENT_ENABLED="${AGENT_ENABLED:-true}"
+AGENT_ENABLED=$(echo "$AGENT_ENABLED" | tr '[:upper:]' '[:lower:]')
+export AGENT_ENABLED
+exec /usr/bin/supervisord -c /etc/supervisor/conf.d/supervisord.conf

supervisord.conf

@@ -12,6 +12,7 @@ priority=10
 [program:agent]
 command=python -m agent.start
 directory=/app
+autostart=%(ENV_AGENT_ENABLED)s
 autorestart=true
 priority=20
 stdout_logfile=/dev/stdout