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Automated nginx proxy for Docker containers using docker-gen

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nginx-proxy sets up a container running nginx and docker-gen. docker-gen generates reverse proxy configs for nginx and reloads nginx when containers are started and stopped.

See Automated Nginx Reverse Proxy for Docker for why you might want to use this.

Usage

To run it:

docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

Then start any containers you want proxied with an env var VIRTUAL_HOST=subdomain.youdomain.com

docker run -e VIRTUAL_HOST=foo.bar.com  ...

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 and be in the same network. By default, if you don't pass the --net flag when your nginx-proxy container is created, it will only be attached to the default bridge network. This means that it will not be able to connect to containers on networks other than bridge.

Provided your DNS is setup to forward foo.bar.com to the host running nginx-proxy, the request will be routed to a container with the VIRTUAL_HOST env var set.

Note: providing a port number in VIRTUAL_HOST isn't suported, please see virtual ports or custom external HTTP/HTTPS ports depending on what you want to achieve.

Image variants

The nginx-proxy images are available in two flavors.

nginxproxy/nginx-proxy:latest

This image uses the debian:buster based nginx image.

docker pull nginxproxy/nginx-proxy:latest

nginxproxy/nginx-proxy:alpine

This image is based on the nginx:alpine image. Use this image to fully support HTTP/2 (including ALPN required by recent Chrome versions). A valid certificate is required as well (see eg. below "SSL Support using an ACME CA" for more info).

docker pull nginxproxy/nginx-proxy:alpine

Docker Compose

version: '2'

services:
  nginx-proxy:
    image: nginxproxy/nginx-proxy
    ports:
      - "80:80"
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro

  whoami:
    image: jwilder/whoami
    expose:
      - "8000"
    environment:
      - VIRTUAL_HOST=whoami.local
      - VIRTUAL_PORT=8000
docker-compose up
curl -H "Host: whoami.local" localhost

Example output:

I'm 5b129ab83266

IPv6 support

You can activate the IPv6 support for the nginx-proxy container by passing the value true to the ENABLE_IPV6 environment variable:

docker run -d -p 80:80 -e ENABLE_IPV6=true -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

Scoped IPv6 Resolvers

NginX does not support scoped IPv6 resolvers. In docker-entrypoint.sh the resolvers are parsed from resolv.conf, but any scoped IPv6 addreses will be removed.

IPv6 NAT

By default, docker uses IPv6-to-IPv4 NAT. This means all client connections from IPv6 addresses will show docker's internal IPv4 host address. To see true IPv6 client IP addresses, you must enable IPv6 and use ipv6nat. You must also disable the userland proxy by adding "userland-proxy": false to /etc/docker/daemon.json and restarting the daemon.

Multiple Hosts

If you need to support multiple virtual hosts for a container, you can separate each entry with commas. For example, foo.bar.com,baz.bar.com,bar.com and each host will be setup the same.

Virtual Ports

When your container exposes only one port, nginx-proxy will default to this port, else to port 80.

If you need to specify a different port, you can set a VIRTUAL_PORT env var to select a different one. This variable cannot be set to more than one port.

For each host defined into VIRTUAL_HOST, the associated virtual port is retrieved by order of precedence:

  1. From the VIRTUAL_PORT environment variable
  2. From the container's exposed port if there is only one
  3. From the default port 80 when none of the above methods apply

Manually Specifying Upstream IP

In case you need to manually override the Upstream IP that Nginx will proxy to, you can declare a VIRTUAL_IP env var. If you do this, you also need to declare the VIRTUAL_PORT env variable as this switches the behaviour to a more "manual" declaration style. This is useful if one of your containers is in network_mode: host for instance.

Wildcard Hosts

You can also use wildcards at the beginning and the end of host name, like *.bar.com or foo.bar.*. Or even a regular expression, which can be very useful in conjunction with a wildcard DNS service like xip.io, using ~^foo\.bar\..*\.xip\.io will match foo.bar.127.0.0.1.xip.io, foo.bar.10.0.2.2.xip.io and all other given IPs. More information about this topic can be found in the nginx documentation about server_names.

Multiple Networks

With the addition of overlay networking in Docker 1.9, your nginx-proxy container may need to connect to backend containers on multiple networks. By default, if you don't pass the --net flag when your nginx-proxy container is created, it will only be attached to the default bridge network. This means that it will not be able to connect to containers on networks other than bridge.

If you want your nginx-proxy container to be attached to a different network, you must pass the --net=my-network option in your docker create or docker run command. At the time of this writing, only a single network can be specified at container creation time. To attach to other networks, you can use the docker network connect command after your container is created:

docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock:ro \
    --name my-nginx-proxy --net my-network nginxproxy/nginx-proxy
docker network connect my-other-network my-nginx-proxy

In this example, the my-nginx-proxy container will be connected to my-network and my-other-network and will be able to proxy to other containers attached to those networks.

Custom external HTTP/HTTPS ports

If you want to use nginx-proxy with different external ports that the default ones of 80 for HTTP traffic and 443 for HTTPS traffic, you'll have to use the environment variable(s) HTTP_PORT and/or HTTPS_PORT in addition to the changes to the Docker port mapping. If you change the HTTPS port, the redirect for HTTPS traffic will also be configured to redirect to the custom port. Typical usage, here with the custom ports 1080 and 10443:

docker run -d -p 1080:1080 -p 10443:10443 -e HTTP_PORT=1080 -e HTTPS_PORT=10443 -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

Internet vs. Local Network Access

If you allow traffic from the public internet to access your nginx-proxy container, you may want to restrict some containers to the internal network only, so they cannot be accessed from the public internet. On containers that should be restricted to the internal network, you should set the environment variable NETWORK_ACCESS=internal. By default, the internal network is defined as 127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. To change the list of networks considered internal, mount a file on the nginx-proxy at /etc/nginx/network_internal.conf with these contents, edited to suit your needs:

# These networks are considered "internal"
allow 127.0.0.0/8;
allow 10.0.0.0/8;
allow 192.168.0.0/16;
allow 172.16.0.0/12;

# Traffic from all other networks will be rejected
deny all;

When internal-only access is enabled, external clients will be denied with an HTTP 403 Forbidden

If there is a load-balancer / reverse proxy in front of nginx-proxy that hides the client IP (example: AWS Application/Elastic Load Balancer), you will need to use the nginx realip module (already installed) to extract the client's IP from the HTTP request headers. Please see the nginx realip module configuration for more details. This configuration can be added to a new config file and mounted in /etc/nginx/conf.d/.

SSL Backends

If you would like the reverse proxy to connect to your backend using HTTPS instead of HTTP, set VIRTUAL_PROTO=https on the backend container.

Note: If you use VIRTUAL_PROTO=https and your backend container exposes port 80 and 443, nginx-proxy will use HTTPS on port 80. This is almost certainly not what you want, so you should also include VIRTUAL_PORT=443.

uWSGI Backends

If you would like to connect to uWSGI backend, set VIRTUAL_PROTO=uwsgi on the backend container. Your backend container should then listen on a port rather than a socket and expose that port.

FastCGI Backends

If you would like to connect to FastCGI backend, set VIRTUAL_PROTO=fastcgi on the backend container. Your backend container should then listen on a port rather than a socket and expose that port.

FastCGI File Root Directory

If you use fastcgi,you can set VIRTUAL_ROOT=xxx for your root directory

Default Host

To set the default host for nginx use the env var DEFAULT_HOST=foo.bar.com for example

docker run -d -p 80:80 -e DEFAULT_HOST=foo.bar.com -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

nginx-proxy will then redirect all requests to a container where VIRTUAL_HOST is set to DEFAULT_HOST, if they don't match any (other) VIRTUAL_HOST. Using the example above requests without matching VIRTUAL_HOST will be redirected to a plain nginx instance after running the following command:

docker run -d -e VIRTUAL_HOST=foo.bar.com nginx

Separate Containers

nginx-proxy can also be run as two separate containers using the jwilder/docker-gen image and the official nginx image.

You may want to do this to prevent having the docker socket bound to a publicly exposed container service.

You can demo this pattern with docker-compose:

docker-compose --file docker-compose-separate-containers.yml up
curl -H "Host: whoami.local" localhost

Example output:

I'm 5b129ab83266

To run nginx proxy as a separate container you'll need to have nginx.tmpl on your host system.

First start nginx with a volume:

docker run -d -p 80:80 --name nginx -v /tmp/nginx:/etc/nginx/conf.d -t nginx

Then start the docker-gen container with the shared volume and template:

docker run --volumes-from nginx \
    -v /var/run/docker.sock:/tmp/docker.sock:ro \
    -v $(pwd):/etc/docker-gen/templates \
    -t jwilder/docker-gen -notify-sighup nginx -watch /etc/docker-gen/templates/nginx.tmpl /etc/nginx/conf.d/default.conf

Finally, start your containers with VIRTUAL_HOST environment variables.

docker run -e VIRTUAL_HOST=foo.bar.com  ...

SSL Support using an ACME CA

acme-companion is a lightweight companion container for the nginx-proxy. It allows the automated creation/renewal of SSL certificates using the ACME protocol.

SSL Support

SSL is supported using single host, wildcard and SNI certificates using naming conventions for certificates or optionally specifying a cert name (for SNI) as an environment variable.

To enable SSL:

docker run -d -p 80:80 -p 443:443 -v /path/to/certs:/etc/nginx/certs -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

The contents of /path/to/certs should contain the certificates and private keys for any virtual hosts in use. The certificate and keys should be named after the virtual host with a .crt and .key extension. For example, a container with VIRTUAL_HOST=foo.bar.com should have a foo.bar.com.crt and foo.bar.com.key file in the certs directory.

If you are running the container in a virtualized environment (Hyper-V, VirtualBox, etc...), /path/to/certs must exist in that environment or be made accessible to that environment. By default, Docker is not able to mount directories on the host machine to containers running in a virtual machine.

Diffie-Hellman Groups

RFC7919 groups with key lengths of 2048, 3072, and 4096 bits are provided by nginx-proxy. The ENV DHPARAM_BITS can be set to 2048 or 3072 to change from the default 4096-bit key. The DH key file will be located in the container at /etc/nginx/dhparam/dhparam.pem. Mounting a different dhparam.pem file at that location will override the RFC7919 key.

To use custom dhparam.pem files per-virtual-host, the files should be named after the virtual host with a dhparam suffix and .pem extension. For example, a container with VIRTUAL_HOST=foo.bar.com should have a foo.bar.com.dhparam.pem file in the /etc/nginx/certs directory.

COMPATIBILITY WARNING: The default generated dhparam.pem key is 4096 bits for A+ security. 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.

In the separate container setup, no pre-generated key will be available and neither the jwilder/docker-gen image, nor the offical nginx image will provide one. If you still want A+ security in a separate container setup, you should mount an RFC7919 DH key file to the nginx container at /etc/nginx/dhparam/dhparam.pem.

Set DHPARAM_SKIP environment variable to true to disable using default Diffie-Hellman parameters. The default value is false.

docker run -e DHPARAM_SKIP=true ....

Wildcard Certificates

Wildcard certificates and keys should be named after the domain name with a .crt and .key extension. For example VIRTUAL_HOST=foo.bar.com would use cert name bar.com.crt and bar.com.key.

SNI

If your certificate(s) supports multiple domain names, you can start a container with CERT_NAME=<name> to identify the certificate to be used. For example, a certificate for *.foo.com and *.bar.com could be named shared.crt and shared.key. A container running with VIRTUAL_HOST=foo.bar.com and CERT_NAME=shared will then use this shared cert.

OCSP Stapling

To enable OCSP Stapling for a domain, nginx-proxy looks for a PEM certificate containing the trusted CA certificate chain at /etc/nginx/certs/<domain>.chain.pem, where <domain> is the domain name in the VIRTUAL_HOST directive. The format of this file is a concatenation of the public PEM CA certificates starting with the intermediate CA most near the SSL certificate, down to the root CA. This is often referred to as the "SSL Certificate Chain". If found, this filename is passed to the NGINX ssl_trusted_certificate directive and OCSP Stapling is enabled.

How SSL Support Works

The default SSL cipher configuration is based on the Mozilla intermediate profile version 5.0 which should provide compatibility with clients back to Firefox 27, Android 4.4.2, Chrome 31, Edge, IE 11 on Windows 7, Java 8u31, OpenSSL 1.0.1, Opera 20, and Safari 9. Note that the DES-based TLS ciphers were removed for security. The configuration also enables HSTS, PFS, OCSP stapling and SSL session caches. Currently TLS 1.2 and 1.3 are supported.

If you don't require backward compatibility, you can use the Mozilla modern profile profile instead by including the environment variable SSL_POLICY=Mozilla-Modern to the nginx-proxy container or to your container. This profile is compatible with clients back to Firefox 63, Android 10.0, Chrome 70, Edge 75, Java 11, OpenSSL 1.1.1, Opera 57, and Safari 12.1. Note that this profile is not compatible with any version of Internet Explorer.

Other policies available through the SSL_POLICY environment variable are Mozilla-Old and the AWS ELB Security Policies AWS-TLS-1-2-2017-01, AWS-TLS-1-1-2017-01, AWS-2016-08, AWS-2015-05, AWS-2015-03 and AWS-2015-02.

Note that the Mozilla-Old policy should use a 1024 bits DH key for compatibility but this container provides a 4096 bits key. The Diffie-Hellman Groups section details different methods of bypassing this, either globally or per virtual-host.

The default behavior for the proxy when port 80 and 443 are exposed is as follows:

  • If a container has a usable cert, port 80 will redirect to 443 for that container so that HTTPS is always preferred when available.
  • If the container does not have a usable cert, a 503 will be returned.

Note that in the latter case, a browser may get an connection error as no certificate is available to establish a connection. A self-signed or generic cert named default.crt and default.key will allow a client browser to make a SSL connection (likely w/ a warning) and subsequently receive a 500.

To serve traffic in both SSL and non-SSL modes without redirecting to SSL, you can include the environment variable HTTPS_METHOD=noredirect (the default is HTTPS_METHOD=redirect). You can also disable the non-SSL site entirely with HTTPS_METHOD=nohttp, or disable the HTTPS site with HTTPS_METHOD=nohttps. HTTPS_METHOD can be specified on each container for which you want to override the default behavior or on the proxy container to set it globally. If HTTPS_METHOD=noredirect is used, Strict Transport Security (HSTS) is disabled to prevent HTTPS users from being redirected by the client. If you cannot get to the HTTP site after changing this setting, your browser has probably cached the HSTS policy and is automatically redirecting you back to HTTPS. You will need to clear your browser's HSTS cache or use an incognito window / different browser.

By default, HTTP Strict Transport Security (HSTS) is enabled with max-age=31536000 for HTTPS sites. You can disable HSTS with the environment variable HSTS=off or use a custom HSTS configuration like HSTS=max-age=31536000; includeSubDomains; preload.

WARNING: HSTS will force your users to visit the HTTPS version of your site for the max-age time - even if they type in http:// manually. The only way to get to an HTTP site after receiving an HSTS response is to clear your browser's HSTS cache.

Basic Authentication Support

In order to be able to secure your virtual host, you have to create a file named as its equivalent VIRTUAL_HOST variable on directory /etc/nginx/htpasswd/$VIRTUAL_HOST

docker run -d -p 80:80 -p 443:443 \
    -v /path/to/htpasswd:/etc/nginx/htpasswd \
    -v /path/to/certs:/etc/nginx/certs \
    -v /var/run/docker.sock:/tmp/docker.sock:ro \
    nginxproxy/nginx-proxy

You'll need apache2-utils on the machine where you plan to create the htpasswd file. Follow these instructions

Custom Nginx Configuration

If you need to configure Nginx beyond what is possible using environment variables, you can provide custom configuration files on either a proxy-wide or per-VIRTUAL_HOST basis.

Replacing default proxy settings

If you want to replace the default proxy settings for the nginx container, add a configuration file at /etc/nginx/proxy.conf. A file with the default settings would look like this:

# HTTP 1.1 support
proxy_http_version 1.1;
proxy_buffering off;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $proxy_connection;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
proxy_set_header X-Forwarded-Ssl $proxy_x_forwarded_ssl;
proxy_set_header X-Forwarded-Port $proxy_x_forwarded_port;

# Mitigate httpoxy attack (see README for details)
proxy_set_header Proxy "";

NOTE: If you provide this file it will replace the defaults; you may want to check the .tmpl file to make sure you have all of the needed options.

NOTE: The default configuration blocks the Proxy HTTP request header from being sent to downstream servers. This prevents attackers from using the so-called httpoxy attack. There is no legitimate reason for a client to send this header, and there are many vulnerable languages / platforms (CVE-2016-5385, CVE-2016-5386, CVE-2016-5387, CVE-2016-5388, CVE-2016-1000109, CVE-2016-1000110, CERT-VU#797896).

Proxy-wide

To add settings on a proxy-wide basis, add your configuration file under /etc/nginx/conf.d using a name ending in .conf.

This can be done in a derived image by creating the file in a RUN command or by COPYing the file into conf.d:

FROM nginxproxy/nginx-proxy
RUN { \
      echo 'server_tokens off;'; \
      echo 'client_max_body_size 100m;'; \
    } > /etc/nginx/conf.d/my_proxy.conf

Or it can be done by mounting in your custom configuration in your docker run command:

docker run -d -p 80:80 -p 443:443 -v /path/to/my_proxy.conf:/etc/nginx/conf.d/my_proxy.conf:ro -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy

Per-VIRTUAL_HOST

To add settings on a per-VIRTUAL_HOST basis, add your configuration file under /etc/nginx/vhost.d. Unlike in the proxy-wide case, which allows multiple config files with any name ending in .conf, the per-VIRTUAL_HOST file must be named exactly after the VIRTUAL_HOST.

In order to allow virtual hosts to be dynamically configured as backends are added and removed, it makes the most sense to mount an external directory as /etc/nginx/vhost.d as opposed to using derived images or mounting individual configuration files.

For example, if you have a virtual host named app.example.com, you could provide a custom configuration for that host as follows:

docker run -d -p 80:80 -p 443:443 -v /path/to/vhost.d:/etc/nginx/vhost.d:ro -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy
{ echo 'server_tokens off;'; echo 'client_max_body_size 100m;'; } > /path/to/vhost.d/app.example.com

If you are using multiple hostnames for a single container (e.g. VIRTUAL_HOST=example.com,www.example.com), the virtual host configuration file must exist for each hostname. If you would like to use the same configuration for multiple virtual host names, you can use a symlink:

{ echo 'server_tokens off;'; echo 'client_max_body_size 100m;'; } > /path/to/vhost.d/www.example.com
ln -s /path/to/vhost.d/www.example.com /path/to/vhost.d/example.com

Per-VIRTUAL_HOST default configuration

If you want most of your virtual hosts to use a default single configuration and then override on a few specific ones, add those settings to the /etc/nginx/vhost.d/default file. This file will be used on any virtual host which does not have a /etc/nginx/vhost.d/{VIRTUAL_HOST} file associated with it.

Per-VIRTUAL_HOST location configuration

To add settings to the "location" block on a per-VIRTUAL_HOST basis, add your configuration file under /etc/nginx/vhost.d just like the previous section except with the suffix _location.

For example, if you have a virtual host named app.example.com and you have configured a proxy_cache my-cache in another custom file, you could tell it to use a proxy cache as follows:

docker run -d -p 80:80 -p 443:443 -v /path/to/vhost.d:/etc/nginx/vhost.d:ro -v /var/run/docker.sock:/tmp/docker.sock:ro nginxproxy/nginx-proxy
{ echo 'proxy_cache my-cache;'; echo 'proxy_cache_valid  200 302  60m;'; echo 'proxy_cache_valid  404 1m;' } > /path/to/vhost.d/app.example.com_location

If you are using multiple hostnames for a single container (e.g. VIRTUAL_HOST=example.com,www.example.com), the virtual host configuration file must exist for each hostname. If you would like to use the same configuration for multiple virtual host names, you can use a symlink:

{ echo 'proxy_cache my-cache;'; echo 'proxy_cache_valid  200 302  60m;'; echo 'proxy_cache_valid  404 1m;' } > /path/to/vhost.d/app.example.com_location
ln -s /path/to/vhost.d/www.example.com /path/to/vhost.d/example.com

Per-VIRTUAL_HOST location default configuration

If you want most of your virtual hosts to use a default single location block configuration and then override on a few specific ones, add those settings to the /etc/nginx/vhost.d/default_location file. This file will be used on any virtual host which does not have a /etc/nginx/vhost.d/{VIRTUAL_HOST}_location file associated with it.

Per-VIRTUAL_HOST server_tokens configuration

Per virtual-host servers_tokens directive can be configured by passing appropriate value to the SERVER_TOKENS environment variable. Please see the nginx http_core module configuration for more details.

Unhashed vs SHA1 upstream names

By default the nginx configuration upstream blocks will use this block's corresponding hostname as a predictable name. However, this can cause issues in some setups (see this issue). In those cases you might want to switch to SHA1 names for the upstream blocks by setting the SHA1_UPSTREAM_NAME environment variable to true on the nginx-proxy container.

Please note that using regular expressions in VIRTUAL_HOST will always result in a corresponding upstream block with an SHA1 name.

Troubleshooting

In case you can't access your VIRTUAL_HOST, set DEBUG=true in the client container's environment and have a look at the generated nginx configuration file /etc/nginx/conf.d/default:

docker exec <nginx-proxy-instance> cat /etc/nginx/conf.d/default

Especially at upstream definition blocks which should look like:

# foo.example.com
upstream foo.example.com {
	## Can be connected with "my_network" network
	# Exposed ports: [{   <exposed_port1>  tcp } {   <exposed_port2>  tcp } ...]
	# Default virtual port: <exposed_port|80>
	# VIRTUAL_PORT: <VIRTUAL_PORT>
	# foo
	server 172.18.0.9:<Port>;
	# Fallback entry
	server 127.0.0.1 down;
}

The effective Port is retrieved by order of precedence:

  1. From the VIRTUAL_PORT environment variable
  2. From the container's exposed port if there is only one
  3. From the default port 80 when none of the above methods apply

Contributing

Before submitting pull requests or issues, please check github to make sure an existing issue or pull request is not already open.

Running Tests Locally

To run tests, you just need to run the command below:

make test

This commands run tests on two variants of the nginx-proxy docker image: Debian and Alpine.

You can run the tests for each of these images with their respective commands:

make test-debian
make test-alpine

You can learn more about how the test suite works and how to write new tests in the test/README.md file.

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