Add networking the right way
This commit is contained in:
parent
3d86e39806
commit
93d03d9016
1 changed files with 194 additions and 0 deletions
194
content/post/05-networking-the-right-way.md
Normal file
194
content/post/05-networking-the-right-way.md
Normal file
|
|
@ -0,0 +1,194 @@
|
|||
---
|
||||
title: "GNU/Linux wireless networking like it's 2020"
|
||||
subtitle: "How to add some systemd stuff inside your network configuration"
|
||||
date: 2020-07-14
|
||||
draft: false
|
||||
tags: [ops, systemd, network, wireless]
|
||||
---
|
||||
|
||||
# From netcl to iwd 📡
|
||||
|
||||
ArchLinux is installed on my laptop (an XPS 15) since I got it from my job in
|
||||
2017[^1]. 3 years ago, the cli tool distributed within the distribution was
|
||||
`netctl`. It's an in-house [ArchLinux
|
||||
project](https://git.archlinux.org/netctl.git/) allowing users to manage
|
||||
networking. Overall, the tool does everything I need to get a
|
||||
network connection up and running the way I need it. One of the main thing I
|
||||
dislike about it is `wifi-menu`, a poorly design UI to search for wireless
|
||||
access points.
|
||||
|
||||
Not so long ago a new challenger appeared : `iwd`. **iNet Wireless Daemon**
|
||||
(iwd) is new wireless daemon for GNU/Linux (a standard tool, available on all
|
||||
distros is better for this kind of tasks). Even if this project aims to
|
||||
replace `wpa_supplicant` it can also replace `netctl`. If you think it's a
|
||||
toy project from some random guy over the internet, bad news for you, that guy
|
||||
is : Intel™. The fact that this program acts as a daemon means one standing
|
||||
point : multiple clients will be available in the future and some well known
|
||||
managers like `network-manager` might also use it. A default one comes with
|
||||
the package as an interactive shell called `iwctl`, bye-bye `wifi-menu` !
|
||||
|
||||
To begin with `iwd` enable and start the service
|
||||
|
||||
```sh
|
||||
systemctl enable --now iwd.service
|
||||
```
|
||||
|
||||
and open the interactive shell
|
||||
|
||||
```sh
|
||||
iwctl
|
||||
```
|
||||
|
||||
then list all networks
|
||||
|
||||
```sh
|
||||
[iwd] station wlan0 get-networks
|
||||
Available networks
|
||||
--------------------------------------------------------------------------------
|
||||
Network name Security Signal
|
||||
--------------------------------------------------------------------------------
|
||||
ORTHANC psk ****
|
||||
MINAS ITHIL psk ****
|
||||
MINAS TIRITH psk ****
|
||||
```
|
||||
|
||||
```sh
|
||||
[iwd] station wlan0 connect ORTHANC
|
||||
```
|
||||
|
||||
Enter the password if needed, it will be saved for later use (in
|
||||
`/var/lib/iwd`) and check if everything is ok :
|
||||
|
||||
```sh
|
||||
[iwd] station wlan0 show
|
||||
Station: wlan0
|
||||
--------------------------------------------------------------------------------
|
||||
Settable Property Value
|
||||
--------------------------------------------------------------------------------
|
||||
Scanning no
|
||||
State connected
|
||||
Connected network ORTHANC
|
||||
```
|
||||
|
||||
On reboot, `iwd` will try to reconnect to last used connection.
|
||||
|
||||
# Adding some salty systemd stuff 🧂
|
||||
|
||||
Connected, sure, but what about an IP address 🤡 ? The first option is
|
||||
obviously `dhcpd` but it scales poorly if you have to type it everytime you
|
||||
connect to a network. Since version 0.19 `iwd` comes with a built-in DHCP
|
||||
client to enable it just add
|
||||
|
||||
```txt
|
||||
[General]
|
||||
EnableNetworkConfiguration=true
|
||||
```
|
||||
|
||||
in `/etc/iwd/main.conf`.
|
||||
|
||||
For some people it's good enough, but you know me, I like systemd a lot and
|
||||
i'm already using `systemd-networkd`[^2] to create various kind of static network
|
||||
interfaces and network connections.
|
||||
|
||||
To let `systemd-networkd` get DHCP configuration for you, ensure `systemd-networkd` is enabled
|
||||
|
||||
```sh
|
||||
systemctl enable --now systemd-networkd.service
|
||||
```
|
||||
|
||||
Now, add a `.network` file (in `/etc/systemd/network`) for the main wifi interface
|
||||
|
||||
```txt
|
||||
[Match]
|
||||
Name=wlan0
|
||||
|
||||
[Network]
|
||||
DHCP=yes
|
||||
```
|
||||
|
||||
The _match_ section is used to identify the interface by name, the _network_
|
||||
one ensures that this configuration comes from DHCP.
|
||||
|
||||
Now that everything is setup, systemd-networkd will get configuration for this
|
||||
interface when requested by changes on wifi interface from `iwctl`.
|
||||
|
||||
# More salt with systemd-resolved 👺
|
||||
|
||||
In order to piss off the ones who hate systemd, I decided to add
|
||||
`systemd-resolved` into the mix.
|
||||
|
||||
`systemd-resolved` is a systemd subservice providing a local DNS system with
|
||||
caching, DNSSEC or the cool new kid : [DNS over
|
||||
TLS](https://en.wikipedia.org/wiki/DNS_over_TLS).
|
||||
|
||||
As usual to enable it :
|
||||
|
||||
```sh
|
||||
systemctl enable --now systemd-resolved.service
|
||||
```
|
||||
|
||||
The common way to change the DNS configuration is the good old
|
||||
`/etc/resolv.conf` file. With `systemd-resolved` the recommended and most
|
||||
disruptive way is to symlink the generated stub file
|
||||
`/run/systemd/resolve/stub-resolv.conf` to `/etc/resolv.conf`.
|
||||
|
||||
```txt
|
||||
# This file is managed by man:systemd-resolved(8). Do not edit.
|
||||
#
|
||||
# This is a dynamic resolv.conf file for connecting local clients to the
|
||||
# internal DNS stub resolver of systemd-resolved. This file lists all
|
||||
# configured search domains.
|
||||
#
|
||||
# Run "resolvectl status" to see details about the uplink DNS servers
|
||||
# currently in use.
|
||||
#
|
||||
# Third party programs should typically not access this file directly, but only
|
||||
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
|
||||
# different way, replace this symlink by a static file or a different symlink.
|
||||
#
|
||||
# See man:systemd-resolved.service(8) for details about the supported modes of
|
||||
# operation for /etc/resolv.conf.
|
||||
|
||||
nameserver 127.0.0.53
|
||||
options edns0
|
||||
search example.lan example.com
|
||||
```
|
||||
|
||||
The stub file contains only the local DNS stub server from `systemd-resolved` (available on 127.0.0.53).
|
||||
|
||||
The main purpose of this server is a caching implementation avoiding useless
|
||||
DNS requests.
|
||||
|
||||
To get an idea of the number of requests where the cache is used, just check statistics
|
||||
|
||||
```sh
|
||||
resolvectl statistics
|
||||
DNSSEC supported by current servers: no
|
||||
|
||||
Transactions
|
||||
Current Transactions: 0
|
||||
Total Transactions: 8544
|
||||
|
||||
Cache
|
||||
Current Cache Size: 65
|
||||
Cache Hits: 2394
|
||||
Cache Misses: 3939
|
||||
```
|
||||
|
||||
To customize `systemd-resolved` configuration, just look at
|
||||
systemd-revolved(8) and the config file in `/etc/systemd/resolved.conf`
|
||||
(`resolvctl` with no argument can be used to get information about the
|
||||
current configuration).
|
||||
|
||||
This is, in my opinion, the best networking config I ever have.
|
||||
|
||||
Happy systemding !
|
||||
|
||||
# Ressources
|
||||
|
||||
- https://wiki.archlinux.org/index.php/Iwd
|
||||
- https://wiki.archlinux.org/index.php/Systemd-networkd
|
||||
- https://wiki.archlinux.org/index.php/Systemd-resolved
|
||||
|
||||
[^1]: And it runs on [btrfs](https://en.wikipedia.org/wiki/Btrfs) with absolutely no troubles for more than 3 years
|
||||
[^2]: A systemd subservice handling networking stuff
|
||||
Loading…
Reference in a new issue