[](https://hub.docker.com/r/jrcs/letsencrypt-nginx-proxy-companion "Click to view the image on Docker Hub")
[](https://hub.docker.com/r/jrcs/letsencrypt-nginx-proxy-companion "Click to view the image on Docker Hub")
[](https://hub.docker.com/r/jrcs/letsencrypt-nginx-proxy-companion "Click to view the image on Docker Hub")
letsencrypt-nginx-proxy-companion is a lightweight companion container for the [nginx-proxy](https://github.com/jwilder/nginx-proxy). It allows the creation/renewal of Let's Encrypt certificates automatically. See [Let's Encrypt section](#lets-encrypt) for configuration details.
***NOTE***: The first time this container is launched it generates a new Diffie-Hellman group file. This process can take several minutes to complete (be patient).
To use it with original [nginx-proxy](https://github.com/jwilder/nginx-proxy) container you must declare 3 writable volumes from the [nginx-proxy](https://github.com/jwilder/nginx-proxy) container:
*`/etc/nginx/certs` to create/renew Let's Encrypt certificates
The "com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy" label is needed so that the letsencrypt container knows which nginx proxy container to use.
The containers being proxied must [expose](https://docs.docker.com/reference/run/#expose-incoming-ports) 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`. See [nginx-proxy](https://github.com/jwilder/nginx-proxy) for more informations. To generate automatically Let's Encrypt certificates see next section.
You may want to do this to prevent having the docker socket bound to a publicly exposed container service (avoid to mount the docker socket in the nginx exposed container). It's better in a security point of view.
To run nginx proxy as a separate container you'll need:
1) To mount the template file [nginx.tmpl](https://github.com/jwilder/nginx-proxy/blob/master/nginx.tmpl) into the docker-gen container. You can get the latest official [nginx.tmpl](https://github.com/jwilder/nginx-proxy/blob/master/nginx.tmpl) with a command like:
2) Use the `com.github.jrcs.letsencrypt_nginx_proxy_companion.docker_gen` label on the docker-gen container, or explicitly set the `NGINX_DOCKER_GEN_CONTAINER` environment variable to the name or id of that container.
If the 3 containers are using static names, both labels `com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy` on nginx container and `com.github.jrcs.letsencrypt_nginx_proxy_companion.docker_gen` on the docker-gen container can be removed.
To use the Let's Encrypt service to automatically create a valid certificate for virtual host(s), declare the `LETSENCRYPT_HOST` environment variable in each to-be-proxied application containers.
The `LETSENCRYPT_HOST` variable most likely needs to be set to the same value as the `VIRTUAL_HOST` variable and must be publicly reachable domains. Specify multiple hosts with a comma delimiter.
**Note:** the `VIRTUAL_HOST` (and `LETSENCRYPT_HOST`) must be (a) reachable domain(s) for LetEncrypt to be able to validate the challenge and provide the certificate.
**Note on CAA**: Please ensure that your DNS provider answers correctly to CAA record requests. [If your DNS provider answer with an error, Let's Encrypt won't issue a certificate for your domain](https://letsencrypt.org/docs/caa/). Let's Encrypt do not require that you set a CAA record on your domain, just that your DNS provider answers correctly.
**Note on IPv6**: If the domain or subdomain you want to issue certificate for has an AAAA record set, Let's Encrypt will favor challenge validation over IPv6. [There is an IPv6 to IPv4 fallback in place but Let's Encrypt cannot guarantee it'll work in every possible case](https://github.com/letsencrypt/boulder/issues/2770#issuecomment-340489871), so bottom line is **if you are not sure of both your host and your host's Docker reachability over IPv6, do not advertise an AAAA record** or LE challenge validation might fail.
The `LETSENCRYPT_EMAIL` variable must be a valid email and will be used by Let's Encrypt to warn you of impeding certificate expiration (should the automated renewal fail) or for account recovery. It is strongly advised to provide a valid contact address using this variable.
If you want to create multi-domain ([SAN](https://www.digicert.com/subject-alternative-name.htm)) certificates add the base domain as the first domain of the `LETSENCRYPT_HOST` environment variable (see [the example](#example) above).
If you want to create test certificates that don't have the 5 certs/week/domain limits define the `LETSENCRYPT_TEST` environment variable with a value of `true` (in the containers where you request certificates with `LETSENCRYPT_HOST`). If you want to do this globally for all containers, set `ACME_CA_URI` as described below.
Every hour (3600 seconds) the certificates are checked and every certificate that will expire in the next [30 days](https://github.com/kuba/simp_le/blob/ecf4290c4f7863bb5427b50cdd78bc3a5df79176/simp_le.py#L72) (90 days / 3) are renewed.
If needed, you can force a running letsencrypt-nginx-proxy-companion container to renew all certificates that are currently in use. Replace `nginx-letsencrypt` with the name of your letsencrypt-nginx-proxy-companion container in the following command:
By default the container will save the first ACME account key created for each ACME API endpoint used, and will reuse it for all subsequent authorizations and issuances requests made to this endpoint. This behavior is enabled by default to avoid running into Let's Encrypt account [rate limits](https://letsencrypt.org/docs/rate-limits/).
For instance, when using the default Let's Encrypt production endpoint, the container will save the first account key created for this endpoint as `/etc/nginx/certs/accounts/acme-v01.api.letsencrypt.org/directory/default.json` and will reuse it for future requests made to this endpoint.
If required, you can use multiple accounts for the same ACME API endpoint by using the `LETSENCRYPT_ACCOUNT_ALIAS` environment variable on your proxyed container. This instruct the letsencrypt_nginx_proxy_companion container to look for an account key named after the provided alias instead of `default.json`. For example, `LETSENCRYPT_ACCOUNT_ALIAS=client1` will use the key named `client1.json` in the corresponding ACME API endpoint folder for this proxyed container (or will create it if it does not exists yet).
Please see the **One Account or Many?** paragraph on [Let's Encrypt Integration Guide](https://letsencrypt.org/docs/integration-guide/) for additional informations.
If you want to disable the account key reutilization entirely, you can set the environment variable `REUSE_ACCOUNT_KEYS` to `false` on the letsencrypt_nginx_proxy_companion container. This creates a new ACME registration with a corresponding account key for each new certificate issuance. Note that this won't create new account keys for certs already issued before `REUSE_ACCOUNT_KEYS` is set to `false`. This is not recommended unless you have specific reasons to do so.
*`ACME_CA_URI` - Directory URI for the CA ACME API endpoint (default: ``https://acme-v01.api.letsencrypt.org/directory``). If you set it's value to `https://acme-staging.api.letsencrypt.org/directory` letsencrypt will use test servers that don't have the 5 certs/week/domain limits. You can also create test certificates per container (see [let's encrypt test certificates](#test-certificates))
*`DEBUG` - Set it to `true` to enable debugging of the entrypoint script and generation of LetsEncrypt certificates, which could help you pin point any configuration issues.
*`REUSE_PRIVATE_KEYS` - Set it to `true` to make simp_le reuse previously generated private key for each certificate instead of creating a new one on certificate renewal. Recommended if you intend to use HPKP.
* The `com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy` label - set this label on the nginx-proxy container to tell the docker-letsencrypt-nginx-proxy-companion container to use it as the proxy.
* The `com.github.jrcs.letsencrypt_nginx_proxy_companion.docker_gen` label - set this label on the docker-gen container to tell the docker-letsencrypt-nginx-proxy-companion container to use it as the docker-gen when it's split from nginx (separate containers).
*`DHPARAM_BITS` - Change the size of the Diffie-Hellman key generated by the container from the default value of 2048 bits. For example `-e DHPARAM_BITS=1024` to support some older clients like Java 6 and 7.
