Domain Configuration

New

Introduced in 0.3.10

domains:add <app> <domain> [<domain> ...]      # Add domains to app
domains:add-global <domain> [<domain> ...]     # Add global domain names
domains [<app>]                                # List domains
domains:clear <app>                            # Clear all domains for app
domains:disable <app>                          # Disable VHOST support
domains:enable <app>                           # Enable VHOST support
domains:remove <app> <domain> [<domain> ...]   # Remove domains from app
domains:remove-global <domain> [<domain> ...]  # Remove global domain names

Info

Adding a domain before deploying an application will result in port mappings being set. This may cause issues for applications that use non-standard ports, as those will not be automatically detected. Please refer to the proxy documentation for information as to how to reconfigure the mappings.

Customizing hostnames

Applications typically have the following structure for their hostname:

scheme://subdomain.domain.tld

The subdomain is inferred from the pushed application name, while the domain.tld is set during initial configuration and stored in the $DOKKU_ROOT/VHOST file. It can then be modified with dokku domains:add-global and dokku domains:remove-global. This value is used as a default TLD for all applications on a host.

If a FQDN such as other.tld is used as the application name, the default $DOKKU_ROOT/VHOST will be ignored and the resulting vhost URL for that application will be other.tld. The exception to this rule being that if the FQDN has the same ending as the default vhost (such as subdomain.domain.tld), then the entire FQDN will be treated as a subdomain. The application will therefore be deployed at subdomain.domain.tld.domain.tld.

You can optionally override this in a plugin by implementing the nginx-hostname plugin trigger. For example, you can reverse the subdomain with the following sample nginx-hostname plugin trigger:

#!/usr/bin/env bash
set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x

APP="$1"; SUBDOMAIN="$2"; VHOST="$3"

NEW_SUBDOMAIN=`echo $SUBDOMAIN | rev`
echo "$NEW_SUBDOMAIN.$VHOST"

If the nginx-hostname has no output, the normal hostname algorithm will be executed.

Disabling VHOSTS

If desired, it is possible to disable vhosts with the domains plugin.

dokku domains:disable myapp

On subsequent deploys, the nginx virtualhost will be discarded. This is useful when deploying internal-facing services that should not be publicly routeable. As of 0.4.0, nginx will still be configured to proxy your app on some random high port. This allows internal services to maintain the same port between deployments. You may change this port by setting DOKKU_NGINX_PORT and/or DOKKU_NGINX_SSL_PORT (for services configured to use SSL.)

The domains plugin allows you to specify custom domains for applications. This plugin is aware of any ssl certificates that are imported via certs:add. Be aware that disabling domains (with domains:disable) will override any custom domains.

# where `myapp` is the name of your app

# add a domain to an app
dokku domains:add myapp example.com

# list custom domains for app
dokku domains myapp

# clear all custom domains for app
dokku domains:clear myapp

# remove a custom domain from app
dokku domains:remove myapp example.com

Default site

By default, Dokku will route any received request with an unknown HOST header value to the lexicographically first site in the nginx config stack. If this is not the desired behavior, you may want to add the following configuration to the global nginx configuration. This will catch all unknown HOST header values and return a 410 Gone response. You can replace the return 410; with return 444; which will cause nginx to not respond to requests that do not match known domains (connection refused).

server {
  listen 80 default_server;
  listen [::]:80 default_server;

  server_name _;
  return 410;
  log_not_found off;
}

You may also wish to use a separate vhost in your /etc/nginx/sites-enabled directory. To do so, create the vhost in that directory as /etc/nginx/sites-enabled/00-default.conf. You will also need to change two lines in the main nginx.conf:

# Swap both conf.d include line and the sites-enabled include line. From:
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;

# to the following

include /etc/nginx/sites-enabled/*;
include /etc/nginx/conf.d/*.conf;

Alternatively, you may push an app to your Dokku host with a name like "00-default". As long as it lists first in ls /home/dokku/*/nginx.conf | head, it will be used as the default nginx vhost.