wg-netns/README.md

# wg-netns

[wg-quick](https://git.zx2c4.com/wireguard-tools/about/src/man/wg-quick.8) with support for Linux network namespaces.
A simple Python script that implements the steps described at [wireguard.com/netns](https://www.wireguard.com/netns/#ordinary-containerization).

## Setup

Requirements:

- Python 3.7 or newer
- `ip` from iproute2
- `wg` from wireguard-tools
- optional: [pyyaml](https://pypi.org/project/PyYAML/) python package for configuration files in YAML format, otherwise only JSON is supported

Installation:

~~~ bash
git clone --depth 1 https://github.com/dadevel/wg-netns.git
sudo ./wg-netns/setup.sh
~~~

## Usage

First, create a configuration profile.
JSON and YAML file formats are supported.

Minimal JSON example:

~~~ json
{
  "name": "ns-example",
  "interfaces": [
    {
      "name": "wg-example",
      "address": ["10.10.10.192/32", "fc00:dead:beef::192/128"],
      "private-key": "4bvaEZHI...",
      "peers": [
        {
          "public-key": "bELgMXGt...",
          "endpoint": "vpn.example.com:51820",
          "allowed-ips": ["0.0.0.0/0", "::/0"]
        }
      ]
    }
  ]
}
~~~

Full YAML example:

~~~ yaml
# name of the network namespace
name: ns-example
# if false, the netns itself won't be created or deleted, just the interfaces inside it
managed: true
# list of dns servers, if empty dns servers from default netns will be used
dns-server: [10.10.10.1, 10.10.10.2]
# shell hooks, e.g. to set firewall rules
pre-up: echo pre-up
post-up: echo post-up
pre-own: echo pre-down
post-down: echo post-down
# list of wireguard interfaces inside the netns
interfaces:
  # interface name, required
- name: wg-site-a
  # list of ip addresses, at least one entry required
  address:
  - 10.10.11.172/32
  - fc00:dead:beef:1::172/128
  private-key: nFkQQjN+...
  # optional settings
  listen-port: 51821
  fwmark: 21
  mtu: 1420
  # list of wireguard peers
  peers:
    # public key is required
  - public-key: Kx+wpJpj...
    # optional settings
    preshared-key: 5daskLoW...
    endpoint: a.example.com:51821
    persistent-keepalive: 25
    # list of ips the peer is allowed to use, at least one entry required
    allowed-ips:
    - 10.10.11.0/24
    - fc00:dead:beef:1::/64
    # by default the networks specified in 'allowed-ips' are routed over the interface, 'routes' can be used to overwrite this behaivor
    routes:
    - 10.10.11.0/24
    - fc00:dead:beef:1::/64
- name: wg-site-b
  address:
  - 10.10.12.172/32
  - fc00:dead:beef:2::172/128
  private-key: guYPuE3X...
  listen-port: 51822
  fwmark: 22
  peers:
  - public-key: NvZMoyrg...
    preshared-key: cFQuyIX/...
    endpoint: b.example.com:51822
    persistent-keepalive: 25
    allowed-ips:
    - 10.10.12.0/24
    - fc00:dead:beef:2::/64
~~~

Now it's time to setup your new network namespace and all associated wireguard interfaces.

~~~ bash
wg-netns up ./example.yaml
~~~

Profiles stored under `/etc/wireguard/` can be referenced by their name.

~~~ bash
wg-netns up example
~~~

You can verify the success with a combination of `ip` and `wg`.

~~~ bash
ip netns exec ns-example wg show
~~~

Or you can spawn a shell inside the netns.

~~~ bash
ip netns exec ns-example bash -i
~~~

Or connect a container to it.

~~~ bash
podman run -it --rm --network ns:/run/netns/ns-example alpine wget -O - https://ipinfo.io
~~~

Or do whatever else you want.

### System Service

You can find a `wg-quick@.service` equivalent at [wg-netns@.service](./wg-netns@.service).
Place your profile in `/etc/wireguard/`, e.g. `example.json`, then start the service.

~~~ bash
systemctl start wg-netns@example.service
~~~

### Port Forwarding

With `socat` you can forward TCP traffic from outside a network namespace to a port inside a network namespace.

~~~ bash
socat tcp-listen:$OUTSIDE_PORT,reuseaddr,fork "exec:ip netns exec $NETNS_NAME socat stdio 'tcp-connect:$INSIDE_PORT',nofork"
~~~

Example: All connections to port 1234/tcp in the main/default netns are forwarded to port 5678/tcp in the *ns-example* namespace.

~~~ bash
# terminal 1, create netns and start http server inside
wg-netns up ns-example
echo 'Hello from ns-example!' > ./hello.txt
ip netns exec ns-example python3 -m http.server 5678
# terminal 2, setup port forwarding
socat tcp-listen:1234,reuseaddr,fork "exec:ip netns exec ns-example socat stdio 'tcp-connect:127.0.0.1:5678',nofork"
# terminal 3, test access
curl http://127.0.0.1:1234/hello.txt
~~~