Nginx Configuration

Dokku uses nginx as its server for routing requests to specific applications. By default, access and error logs are written for each app to /var/log/nginx/${APP}-access.log and /var/log/nginx/${APP}-error.log respectively

nginx:access-logs <app> [-t]             # Show the nginx access logs for an application (-t follows)
nginx:build-config <app>                 # (Re)builds nginx config for given app
nginx:error-logs <app> [-t]              # Show the nginx error logs for an application (-t follows)

Customizing the nginx configuration

New

Introduced in 0.5.0

Dokku uses a templating library by the name of sigil to generate nginx configuration for each app. You may also provide a custom template for your application as follows:

Copy the following example template to a file named nginx.conf.sigil and either:
If using a buildpack application, you must check it into the root of your app repo.
ADD it to your dockerfile WORKDIR
if your dockerfile has no WORKDIR, ADD it to the /app folder

Info

When using a custom nginx.conf.sigil file, depending upon your application configuration, you may be exposing the file externally. As this file is extracted before the container is run, you can, safely delete it in a custom entrypoint.sh configured in a Dockerfile ENTRYPOINT.

Info

The default template is available here, and can be used as a guide for your own, custom nginx.conf.sigil file. Please refer to the appropriate template file version for your Dokku version.

Available template variables

{{ .APP }}                          Application name
{{ .APP_SSL_PATH }}                 Path to SSL certificate and key
{{ .DOKKU_ROOT }}                   Global Dokku root directory (ex: app dir would be `{{ .DOKKU_ROOT }}/{{ .APP }}`)
{{ .DOKKU_APP_LISTENERS }}          List of IP:PORT pairs of app containers
{{ .PROXY_PORT }}                   Non-SSL nginx listener port (same as `DOKKU_PROXY_PORT` config var)
{{ .PROXY_SSL_PORT }}               SSL nginx listener port (same as `DOKKU_PROXY_SSL_PORT` config var)
{{ .NOSSL_SERVER_NAME }}            List of non-SSL VHOSTS
{{ .PROXY_PORT_MAP }}               List of port mappings (same as `DOKKU_PROXY_PORT_MAP` config var)
{{ .PROXY_UPSTREAM_PORTS }}         List of configured upstream ports (derived from `DOKKU_PROXY_PORT_MAP` config var)
{{ .RAW_TCP_PORTS }}                List of exposed tcp ports as defined by Dockerfile `EXPOSE` directive (**Dockerfile apps only**)
{{ .SSL_INUSE }}                    Boolean set when an app is SSL-enabled
{{ .SSL_SERVER_NAME }}              List of SSL VHOSTS

Note

Application config variables are available for use in custom templates. To do so, use the form of {{ var "FOO" }} to access a variable named FOO.

Customizing via configuration files included by the default templates

The default nginx.conf template will include everything from your apps nginx.conf.d/ subdirectory in the main server {} block (see above):

include {{ .DOKKU_ROOT }}/{{ .APP }}/nginx.conf.d/*.conf;

That means you can put additional configuration in separate files, for example to limit the uploaded body size to 50 megabytes, do

mkdir /home/dokku/node-js-app/nginx.conf.d/
echo 'client_max_body_size 50m;' > /home/dokku/node-js-app/nginx.conf.d/upload.conf
chown dokku:dokku /home/dokku/node-js-app/nginx.conf.d/upload.conf
service nginx reload

The example above uses additional configuration files directly on the Dokku host. Unlike the nginx.conf.sigil file, these additional files will not be copied over from your application repo, and thus need to be placed in the /home/dokku/node-js-app/nginx.conf.d/ directory manually.

For PHP Buildpack users, you will also need to provide a Procfile and an accompanying nginx.conf file to customize the nginx config within the container. The following are example contents for your Procfile

web: vendor/bin/heroku-php-nginx -C nginx.conf -i php.ini php/

Your nginx.conf file - not to be confused with Dokku's nginx.conf.sigil - would also need to be configured as shown in this example:

client_max_body_size 50m;
location / {
    index index.php;
    try_files $uri $uri/ /index.php$is_args$args;
}

Please adjust the Procfile and nginx.conf file as appropriate.

Custom Error Pages

By default, Dokku provides custom error pages for the following three categories of errors:

4xx: For all non-404 errors with a 4xx response code.
404: For "404 Not Found" errors.
5xx: For all 5xx error responses

These are provided as an alternative to the generic Nginx error page, are shared for all applications, and their contents are located on disk at /var/lib/dokku/data/nginx-vhosts/dokku-errors. To customize them for a specific app, create a custom nginx.conf.sigil as described above and change the paths to point elsewhere.