docker-letsencrypt-nginx-proxy-companion/docs/Container-configuration.md

Optional container environment variables for custom configuration.

• ACME_CA_URI - Directory URI for the CA ACME API endpoint (defaults to https://acme-v02.api.letsencrypt.org/directory).

If you set this environment variable value to https://acme-staging-v02.api.letsencrypt.org/directory the container will obtain its certificates from Let's Encrypt test API endpoint that don't have the 5 certs/week/domain limit (but are not trusted by browsers).

For example

$ docker run --detach \
    --name nginx-proxy-acme \
    --volumes-from nginx-proxy \
    --volume /var/run/docker.sock:/var/run/docker.sock:ro \
    --volume certs:/etc/nginx/certs:rw \
    --volume acme:/etc/acme.sh \
    --env "ACME_CA_URI=https://acme-staging-v02.api.letsencrypt.org/directory" \
    nginxproxy/acme-companion

You can also create test certificates per container (see Test certificates)

• DEBUG - Set it to 1 to enable debugging of the entrypoint script and generation of LetsEncrypt certificates, which could help you pin point any configuration issues.

• RENEW_PRIVATE_KEYS - Set it to false to make acme.sh reuse previously generated private key for each certificate instead of creating a new one on certificate renewal. Reusing private keys can help if you intend to use HPKP, but please note that HPKP has been deprecated by Google's Chrome and that it is therefore strongly discouraged to use it at all.

• DHPARAM_BITS - Change the key size of the RFC7919 Diffie-Hellman group used by the container from the default value of 4096 bits. Supported values are 2048, 3072 and 4096. The DH group file will be located in the container at /etc/nginx/certs/dhparam.pem. Mounting a different dhparam.pem file at that location will override the RFC7919 group creation by the acme-companion container. COMPATIBILITY WARNING: some older clients (like Java 6 and 7) do not support DH keys with over 1024 bits. In order to support these clients, you must provide your own dhparam.pem.

• DHPARAM_SKIP - Set it to true to disable the Diffie-Hellman group creation by the container entirely.

• CA_BUNDLE - This is a test only variable for use with Pebble. It changes the trusted root CA used by acme.sh, from the default Alpine trust store to the CA bundle file located at the provided path (inside the container). Do not use it in production unless you are running your own ACME CA.

• CERTS_UPDATE_INTERVAL - 3600 seconds by default, this defines how often the container will check if the certificates require update.