acme-companion is a lightweight companion container for nginx-proxy.
It handles the automated creation, renewal and use of SSL certificates for proxied Docker containers through the ACME protocol.
Features:
- Automated creation/renewal of Let's Encrypt (or other ACME CAs) certificates using acme.sh.
- Let's Encrypt / ACME domain validation through
http-01challenge only. - Automated update and reload of nginx config on certificate creation/renewal.
- Support creation of Multi-Domain (SAN) Certificates.
- Creation of a strong RFC7919 Diffie-Hellman Group at startup.
- Work with all versions of docker.
Requirements:
- Your host must be publicly reachable on both port
80and443. - Check your firewall rules and do not attempt to block port
80as that will preventhttp-01challenges from completing. - For the same reason, you can't use nginx-proxy's
HTTPS_METHOD=nohttp. - The (sub)domains you want to issue certificates for must correctly resolve to the host.
- Your DNS provider must answer correctly to CAA record requests.
- If your (sub)domains have AAAA records set, the host must be publicly reachable over IPv6 on port
80and443.
Basic usage (with the nginx-proxy container)
Three writable volumes must be declared on the nginx-proxy container so that they can be shared with the acme-companion container:
/etc/nginx/certsto store certificates and private keys (readonly for the nginx-proxy container)./etc/nginx/vhost.dto change the configuration of vhosts (required so the CA may accesshttp-01challenge files)./usr/share/nginx/htmlto writehttp-01challenge files.
Additionally, a fourth volume must be declared on the acme-companion container to store acme.sh configuration and state: /etc/acme.sh.
Please also read the doc about data persistence.
Example of use:
Step 1 - nginx-proxy
Start nginx-proxy with the three additional volumes declared:
$ docker run --detach \
--name nginx-proxy \
--publish 80:80 \
--publish 443:443 \
--volume certs:/etc/nginx/certs \
--volume vhost:/etc/nginx/vhost.d \
--volume html:/usr/share/nginx/html \
--volume /var/run/docker.sock:/tmp/docker.sock:ro \
nginxproxy/nginx-proxy
Binding the host docker socket (/var/run/docker.sock) inside the container to /tmp/docker.sock is a requirement of nginx-proxy.
Step 2 - acme-companion
Start the acme-companion container, getting the volumes from nginx-proxy with --volumes-from:
$ docker run --detach \
--name nginx-proxy-acme \
--volumes-from nginx-proxy \
--volume /var/run/docker.sock:/var/run/docker.sock:ro \
--volume acme:/etc/acme.sh \
--env "DEFAULT_EMAIL=mail@yourdomain.tld" \
nginxproxy/acme-companion
The host docker socket has to be bound inside this container too, this time to /var/run/docker.sock.
Albeit optional, it is recommended to provide a valid default email address through the DEFAULT_EMAIL environment variable, so that Let's Encrypt can warn you about expiring certificates and allow you to recover your account.
Step 3 - proxied container(s)
Once both nginx-proxy and acme-companion containers are up and running, start any container you want proxied with environment variables VIRTUAL_HOST and LETSENCRYPT_HOST both set to the domain(s) your proxied container is going to use.
VIRTUAL_HOST control proxying by nginx-proxy and LETSENCRYPT_HOST control certificate creation and SSL enabling by acme-companion.
Certificates will only be issued for containers that have both VIRTUAL_HOST and LETSENCRYPT_HOST variables set to domain(s) that correctly resolve to the host, provided the host is publicly reachable.
$ docker run --detach \
--name your-proxied-app \
--env "VIRTUAL_HOST=subdomain.yourdomain.tld" \
--env "LETSENCRYPT_HOST=subdomain.yourdomain.tld" \
nginx
The containers being proxied must expose the port to be proxied, either by using the EXPOSE directive in their Dockerfile or by using the --expose flag to docker run or docker create.
If the proxied container listen on and expose another port than the default 80, you can force nginx-proxy to use this port with the VIRTUAL_PORT environment variable.
Example using Grafana (expose and listen on port 3000):
$ docker run --detach \
--name grafana \
--env "VIRTUAL_HOST=othersubdomain.yourdomain.tld" \
--env "VIRTUAL_PORT=3000" \
--env "LETSENCRYPT_HOST=othersubdomain.yourdomain.tld" \
--env "LETSENCRYPT_EMAIL=mail@yourdomain.tld" \
grafana/grafana
Repeat Step 3 for any other container you want to proxy.
Additional documentation
Please check the docs section.