Network Namespace setup using SSH SOCKS proxy

Create network namespace where all¹ network requests go via ssh connection.

Installing

1. Install from AUR.
2. Download and install pre-built archlinux package: link.
3. For other linux, copy the files to appropriate path as done here.

Creating new namespace

1. Create a simple ssh config at /etc/nnss/<namespace_name>/config. This will be included with other settings.
2. Copy your ssh private key to /etc/nnss/<namespace_name>/privatekey
3. Edit your service file to include below properties

[Unit]
Requires=nnss-tunsocks@<namespace_name>.service
After=nnss-tunsocks@<namespace_name>.service
[Service]
NetworkNamespacePath=/run/netns/<namespace_name>ns

Example

❯ sudo mkdir /etc/nnss/vps1

❯ sudo tee /etc/nnss/vps1/config > /dev/null
Hostname xx.xx.xx.xx
User vps_user_name_here
Port 8822 # If the ssh server is not on default port 22

❯ cp ~/.ssh/id_ed25519_for_vps1 /etc/nnss/vps1/privatekey

Testing namespace

❯ sudo systemd-run \
    --property=NetworkNamespacePath=/run/netns/vps1ns \
    --property=User=$USER \
    --property=Requires=nnss-tunsocks@vps1.service \
    --property=After=nnss-tunsocks@vps1.service  \
    --shell
[sudo] password for balki:
Running as unit: run-p233279-i233579.service
Press ^] three times within 1s to disconnect TTY.

❯ curl https://ip.balki.me/ip
xx.xx.xx.xx

❯ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host proto kernel_lo
       valid_lft forever preferred_lft forever
18: tunvps1: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 500
    link/none
    inet 198.19.1.1/30 scope global tunvps1
       valid_lft forever preferred_lft forever
    inet6 fe80::fd64:c3f3:ce6:650c/64 scope link stable-privacy proto kernel_ll
       valid_lft forever preferred_lft forever

❯
Finished with result: success
Main processes terminated with: code=exited, status=0/SUCCESS
Service runtime: 1min 4.383s
CPU time consumed: 201ms
Memory peak: 5.7M (swap: 0B)
IP traffic received: 3.2K sent: 1.3K
IO bytes written: 304K

¹DNS

DNS by default still goes via host.