Lancache-DNS

Introduction

This docker container provides DNS entries for caching services to be used in conjunction with a container.

The DNS is generated automatically at startup of the container, the list of supported services is available here

The primary use case is gaming events, such as LAN parties, which need to be able to cope with hundreds or thousands of computers receiving an unannounced patch - without spending a fortune on internet connectivity. Other uses include smaller networks, such as Internet Cafes and home networks, where the new games are regularly installed on multiple computers; or multiple independent operating systems on the same computer.

Quick Explanation

For a LAN cache to function on your network you need two services.

A depot cache service e.g monolithic
A special DNS service e.g this container

The depot cache service transparently proxies your requests for content to Steam/Origin/Etc, or serves the content to you if it already has it.

The special DNS service handles DNS queries normally (recursively), except when they’re about a cached service and in that case it responds that the depot cache service should be used.

Usage

If you are using a single Monolithic instance, you should make sure you set USE_GENERIC_CACHE=true and set LANCACHE_IP to the IP address of the caching server.

Run the lancache-dns container using the following to allow UDP port 53 (DNS) through the host machine:

docker run --name lancache-dns -p 10.0.0.2:53:53/udp -e USE_GENERIC_CACHE=true -e LANCACHE_IP=10.0.0.3 lancachenet/lancache-dns:latest

If you are running a dedicated Monolithic instance for a particular CDN, you can specify a different IP for each service hosted within the cache. For a full list of supported services have a look at uklans/cache-domains. Set the IP for a service using ${SERVICE}CACHE_IP environment:

LANCACHE_IP (requires USE_GENERIC_CACHE to be set to true)

BLIZZARDCACHE_IP
FRONTIERCACHE_IP
ORIGINCACHE_IP
RIOTCACHE_IP
STEAMCACHE_IP
UPLAYCACHE_IP

If you are using USE_GENERIC_CACHE and LANCACHE_IP you can choose to disable any of the cache dns resolvers by setting the environment variable of DISABLE_${SERVICE}=true

DISABLE_BLIZZARD
DISABLE_RIOT
DISABLE_UPLAY

To use a custom upstream DNS server, use the UPSTREAM_DNS variable:

docker run --name lancache-dns -p 10.0.0.2:53:53/udp -e STEAMCACHE_IP=10.0.0.3 -e UPSTREAM_DNS=8.8.8.8 lancachenet/lancache-dns:latest

This will add a forwarder for all queries not served by steamcache to be sent to the upstream DNS server, in this case Google’s DNS. If you have a DNS server on 1.2.3.4, the command argument would be -e UPSTREAM_DNS=1.2.3.4.

Multiple IPs

Should you wish a cache server to have multiple IP addresses (for example a monolithic instance tuned for steam) you may specify them as a space delimited list within quotes for example: -e STEAMCACHE_IP="1.2.3.4 5.6.7.8"

Custom DNS Records

If you would like to add custom records to your DNS server (for example additional services, ad-blocking, etc) you can do so by adding records to the /etc/bind/cache/custom.db file within the container. The easiest way to do this, upon container creation, is to bind a local file to a container file.

To do that, the command argument would be: -v /<host path here>/custom.db:/etc/bind/cache/custom.db

Here is an example of what that custom.db could look like:

notes.<your domain>        A       10.0.0.230
games.<your domain>        A       10.0.0.230
files.<your domain>        A       10.0.0.231

The custom.db uses the RPZ zone format. For more information on the RPZ format, see the BIND9 documentation.

Running on Startup

Follow the instructions in the Docker documentation to run the container at startup. Documentation

Custom Forks/Branches

See cache_domains for details on how to use a non-standard list of hostnames for this container.