# sdns

**Repository Path**: wheatj/sdns

## Basic Information

- **Project Name**: sdns
- **Description**: No description available
- **Primary Language**: Go
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2023-10-15
- **Last Updated**: 2023-10-15

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

<h1 align="center">sdns 📂  </h1>

<h5 align="center">A DNS server based on minimal static configuration</h5>

<br/>

[![Build Status](https://travis-ci.org/cirocosta/sdns.svg?branch=master)](https://travis-ci.org/cirocosta/sdns)


### Use cases

#### Make a domain always resolve to localhost

```
sudo sdns \
        --port 53 \
        --addr 127.0.0.11 \
        'domain=test.cirocosta.io,ip=192.168.0.103,ns=mynameserver.com' \
        'domain=*.cirocosta.io,ip=127.0.0.1,ip=10.0.0.10'
```


#### Retrieve information about each DNS request being performed

```
sudo sdns \
        --debug \               # logs the requests to 'stderr'
        --port 53 \             
        --addr 127.0.0.11 \
        --recursor 8.8.8.8
```

### Install

Pick the latest version in the [project's releases page](https://github.com/cirocosta/sdns/releases) and then "untar" the binary to the desired location in `$PATH`.

For instance:

```
URL=https://github.com/cirocosta/sdns/releases/download/v0.0.1/sdns_0.0.1_darwin_amd64.tar.gz
mkdir -p /tmp/sdns
curl -o /tmp/sdns/sdns.tar.gz -L $URL
tar xzfv /tmp/sdns/sdns.tar.gz -C /tmp/sdns
sudo mv /tmp/sdns/sdns /usr/local/bin/sdns
```

Note.: you can also use `go` to install it: `go get -u github.com/cirocosta/sdns`. Just make sure that you can run the binary with the necessary privileges to bind to port `53`.

### Docker

Using `sdns` in a Docker container is completely fine, you can find the image under [cirocosta/sdns](https://hub.docker.com/r/cirocosta/sdns).

```
docker run -d \
        --network host \        # use the host network stack (not required)
        cirocosta/sdns \        # use the image
        --debug \               # logs the requests to 'stderr'
        --port 53 \             
        --addr 127.0.0.11 \
        --recursor 8.8.8.8
```

### Usage

```
Usage: sdns [--port PORT] [--address ADDRESS] [--debug] [--recursor RECURSOR] [DOMAINS [DOMAINS ...]]

Positional arguments:
  DOMAINS                list of domains

Options:
  --port PORT, -p PORT   port to listen to [default: 1053]
  --address ADDRESS, -a ADDRESS
                         address to bind to
  --debug, -d            turn debug mode on [default: true]
  --recursor RECURSOR, -r RECURSOR
                         list of recursors to honor [default: [8.8.8.8 8.8.4.4]]
  --help, -h             display this help and exit
```

### Running as the system's DNS

### Ubuntu 17.04

If you're on Ubuntu 17.04 you might have noticed that `systemd` places a DNS resolver at `127.0.0.53`:

```sh
cat /etc/resolv.conf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.

127.0.0.53
```

As `systemd-resolve` is a `systemd` service like any other, we just need to stop the unit and then place `sdns` at `127.0.0.53` listening on the default DNS service port (`53`):

```
sudo systemctl stop systemd-resolved
sudo sdns \                             # run as sudo to be able to bind to 53
        --debug \                       # with --debug we capture more logs
        --address 127.0.0.53 \          # listen on the expected IP
        --port 53                       # on port 53

# Now if you stop 'sdns' you'll lose DNS resolving.
# To get systemd-resolve in place again just
# issue `sudo systemctl start systemd-resolved`.
```

Now you can head to your web browser and see the queries coming to SDNS.

If you wish you can also run `sdns` as a `systemd` service (like `systemd-resolved`)