I am working on this django docker project template with this certbot setup, Dockerfile
FROM certbot/certbot:v1.27.0
COPY certify-init.sh /opt/
RUN chmod +x /opt/certify-init.sh
ENTRYPOINT ["/opt/certify-init.sh"]
entrypoint
#!/bin/sh
set -e
echo "Getting certificate..."
certbot certonly \
--webroot \
--webroot-path "/vol/www/" \
-d "$DOMAIN" \
--email $EMAIL \
--rsa-key-size 4096 \
--agree-tos \
--noninteractive
if [ $? -ne 0 ]; then
echo "Certbot encountered an error. Exiting."
exit 1
fi
#for copying the certificate and configuration to the volume
if [ -f "/etc/letsencrypt/live/${DOMAIN}/fullchain.pem" ]; then
echo "SSL cert exists, enabling HTTPS..."
envsubst '${DOMAIN}' < /etc/nginx/nginx.prod.conf > /etc/nginx/conf.d/default.conf
echo "Reloading Nginx configuration..."
nginx -s reload
else
echo "Certbot unable to get SSL cert,server HTTP only..."
fi
echo "Setting up auto-renewal..."
apk add --no-cache dcron
echo "0 12 * * * /usr/bin/certbot renew --quiet" | crontab -
crond -b
problem with this setup is,certbot exits after initial run of getting the certificate and when it’s renew time it require manual intervention.
Now There are two choices
-
set
restart: unless-stopped
in docker compose file so it keeps restarting the container and with cron job to renew the certificate when required. -
Set cron job in host machine to restart the container.
Are there any other/more option to tackle this situation.
The
-b
incrond -b
means to run it as a daemon (in the background), though it appears that is also the default (source). This means the script will continue, but since that’s the last line it exits. With the entrypoint stopped, the container also stops.The fix should be to replace that line with
exec crond -f
so thecrond
process runs in the foreground and becomes the main process running in the container, replacing the entrypoint script.crond -f
withoutexec
should also work, but that needlessly keeps an extra process (the shell running the entrypoint script) alive.guess this will get the job done.
with exec it throws
setpgid: operation not permitted
Due to permission issues with the Docker user group, will avoid using exec as it introduces a potential security risk, which isn’t a sensible trade-off just to keep a process running in the background.