CoreDNS - ads Plugin

DNS AdBlocker plugin for CoreDNS.

Compiling

First get the CoreDNS source code by running, after you cloned this repository into the proper path in your GOPATH

go get github.com/coredns/coredns

Then navigate to the coredns directory

cd $(go env GOPATH)/src/github.com/coredns/coredns

Next update the plugin.cfg in the root of the coredns repository as follows

sed -i 's|loadbalance:loadbalance|ads:github.com/c-mueller/ads\nloadbalance:loadbalance|g' plugin.cfg

while I would suggest having the ads plugin before the cache plugin because it will cause the changes in the blocklists to be applied instantly. However the overall performance of the DNS server could degrade when having many regex rules. In that case I recommend putting the plugin before the hosts plugin:

sed -i 's|hosts:hosts|ads:github.com/c-mueller/ads\nhosts:hosts|g' plugin.cfg

Finally run make to build CoreDNS with the ads plugin

The releases section also contains binaries of the latest CoreDNS with the ads plugin. These get built automatically using drone. Once they have been triggered.

Building development binaries

Building untagged code is complicated. The simplest way i've stumbled upon for CoreDNS is mimicing a in tree plugin using symlinks.

For this you have to create a symlink to the ads repository in the plugins/ folder using a command similar to the following: Assuming you are in the plugins/ directory

ln -s ~/go/src/github.com/c-mueller/ads ads

Make sure to replace ~/go/src/github.com/c-mueller/ads with the proper path to the ads repo.

Next we have to insert the plugin into the plugin.cfg. here we use the following command, instead of the one above:

sed -i 's|loadbalance:loadbalance|ads:ads\nloadbalance:loadbalance|g' plugin.cfg

Before running make in the CoreDNS repo we have to make sure the ads repo does not contain a go.mod file. to do this we rename it to go.mod.old. If you want to continue developing using Goland for example. The file should be renamed again to make sure syntax highlighting works.

A note on go modules

To prevent version conflicts between CoreDNS and the ads plugin it is important to keep the go.mod file empty or if dependencies have been added that are not used by coreDNS only these should be added in the go.mod file on master. For reference the empty go.mod file looks like this:

module github.com/c-mueller/ads

go 1.12

The go sum file should get deleted.

Because this strategy will make development annoying you can run go mod tidy to regenerate a proper go,mod file.

Configuring

The following shows how to use the ads plugin with default parameters, if you want to configure it further take a look at This Document.

Default settings

Running the ads plugin with all defaults is done by just adding the ads keyword to your Corefile.

For example:

.:53 {
    ads
    forward . 1.1.1.1
    log
    errors
}

License

This plugin is licensed under Apache 2 License. See LICENSE for more information.