4.9 KiB
DNSCrypt server Docker image
Run your own caching, non-censoring, non-logging, DNSSEC-capable, DNSCrypt-enabled DNS resolver virtually anywhere!
If you are already familiar with Docker, it shouldn't take more than 5 minutes to get your resolver up and running.
Installation
Think about a name. This is going to be part of your DNSCrypt provider name.
If you are planning to make your resolver publicly accessible, this name will
be public.
It has to look like a domain name (example.com
), but it doesn't have to be
a registered domain.
Let's pick example.com
here.
Download, create and initialize the container, once and for all:
$ docker run --name=dnscrypt-server -p 443:443/udp -p 443:443/tcp --net=host \
jedisct1/dnscrypt-server init -N example.com -E 192.168.1.1:443
This will only accept connections via DNSCrypt on the standard port (443). Replace
192.168.1.1
with the actual external IP address (not the internal Docker one)
clients will connect to.
--net=host
provides the best network performance, but may have to be
removed on some shared containers hosting services.
Now, to start the whole stack:
$ docker start dnscrypt-server
Done.
Note that the actual provider name for DNSCrypt is 2.dnscrypt-cert.example.com
,
not just example.com
as initially entered. The full name has to start with
2.dnscrypt-cert.
for the client and the server to use the same version of the
protocol.
Customizing Unbound
To add new configuration to Unbound, add files to the /opt/unbound/etc/unbound/zones
directory. All files ending in .conf
will be processed. In this manner, you
can add any directives to the server:
section of the Unbound configuration.
Serve custom DNS records on a local network
While Unbound is not a full authoritative name server, it supports resolving
custom entries in a way that is serviceable on a small, private LAN. You can use
unbound to resolve private hostnames such as my-computer.example.com
within
your LAN.
To support such custom entries using this image, first map a volume to the zones
directory. Add this to your docker run
line:
-v /myconfig/zones:/opt/unbound/etc/unbound/zones
The whole command to create and initialize a container would look something like this:
$ docker run --name=dnscrypt-server \
-v /myconfig/zones:/opt/unbound/etc/unbound/zones \
-p 443:443/udp -p 443:443/tcp --net=host \
jedisct1/dnscrypt-server init -N example.com -E 192.168.1.1:443
Create a new .conf
file:
$ touch /myconfig/zones/example.conf
Now, add one or more unbound directives to the file, such as:
local-zone: "example.com." static
local-data: "my-computer.example.com. IN A 10.0.0.1"
local-data: "other-computer.example.com. IN A 10.0.0.2"
Troubleshooting
If Unbound doesn't like one of the newly added directives, it will probably not respond over the network. In that case, here are some commands to work out what is wrong:
$ docker logs dnscrypt-server
$ docker exec dnscrypt-server /opt/unbound/sbin/unbound-checkconf
Details
- Caching resolver: Unbound, with DNSSEC, prefetching, and no logs. The number of threads and memory usage are automatically adjusted. Latest stable version, compiled from source. qname minimisation is enabled.
- LibreSSL - Latest stable version, compiled from source.
- libsodium - Latest stable version, minimal build compiled from source.
- dnscrypt-wrapper - Latest stable version, compiled from source.
Keys and certificates are automatically rotated every 12 hour.
Kubernetes
Kubernetes configurations are located in the kube
directory. Currently these assume
a persistent disk named dnscrypt-keys
on GCE. You will need to adjust the volumes
definition on other platforms. Once that is setup, you can have a dnscrypt server up
in minutes.
- Create a static IP on GCE. This will be used for the LoadBalancer.
- Edit
kube/dnscrypt-init-job.yml
and changeexample.com
to your desired hostname. - Edit
kube/dnscrypt-srv.yml
and changeloadBalancerIP
to your static IP. - Run
kubectl create -f kube/dnscrypt-init-job.yml
to setup your keys. - Run
kubectl create -f kube/dnscrypt-deployment.yml
to deploy the dnscrypt server. - Run
kubectl create -f kube/dnscrypt-srv.yml
to expose your server to the world.
To get your public key just view the logs for the dnscrypt-init
job. The public
IP for your server is merely the dnscrypt
service address.
Coming up next
- Better isolation of the certificate signing process, in a dedicated container.