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doh: NGINX module for serving DNS-over-HTTPS (DOH) requests

Installation

You can install this module in any RHEL-based distribution, including, but not limited to:

  • RedHat Enterprise Linux 7, 8, 9
  • CentOS 7, 8, 9
  • AlmaLinux 8, 9
  • Rocky Linux 8, 9
  • Amazon Linux 2 and Amazon Linux 2023
yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install nginx-module-doh

Enable the module by adding the following at the top of /etc/nginx/nginx.conf:

load_module modules/ngx_http_doh_module.so;

This document describes nginx-module-doh v0.1 released on Jan 15 2020.

Simple Nginx module for serving DNS-over-HTTPS (DOH) requests.

CAVEAT EMPTOR: This module is experimental, even though I have been using it successfully with both Firefox and Curl, there may be undiscovered bugs. Zone transfer is currently not officially supported.

Tested with Nginx versions: 1.16.1 (stable) 1.17.6 1.17.7 (mainline).

Instructions for building installing and using Nginx modules can be found at the links below.

dynamic: https://www.nginx.com/resources/wiki/extending/converting/#compiling-dynamic

static: https://www.nginx.com/resources/wiki/extending/compiling/

I have included a config file for both building as both a dynamic and static module.

This module is only allowed to be used in an http location block.

MODULE DIRECTIVES

doh: (takes no arguments) enable DOH at this location block, default upstream DNS server address is 127.0.0.1, default port is 53, and default timeout is 5 seconds.

doh_address: (takes 1 argument) sets the address of the upstream DNS server, can be either IPv4 or IPv6.

doh_port: (takes 1 argument) sets the port to contact the upstream DNS server on (appies to both TCP and UDP connections).

doh_timeout: (takes 1 argument) sets the timeout in seconds.

EXAMPLES

simplest use case with upstream DNS server listening on 127.0.0.1 on port 53:

location /dns-query { 
    doh;
}

set an upstream address of 127.0.2.1, a port of 5353, and a timeout of 2 seconds:

location /dns-query { 
    doh;
    doh_address 127.0.2.1;
    doh_port 5353;
    doh_timeout 2;
}

GitHub

You may find additional configuration tips and documentation for this module in the GitHub repository for nginx-module-doh.