Kanata on Fedora

Introduction#

Someone noticed that I can’t really touch-type, let alone type with all ten fingers (four is more like it). Since this had been a weak spot for a long time, I decided to change that. Despite a really cool demonstration of the Colemak-DH-Wide layout, with Caps Lock as an additional temporary layer switch for reaching the cursor keys and a few others from the home row, I don’t want to learn a layout that I won’t find by default on most computers. So I’ll stick with QWERTY.

But the temporary Caps Lock layer is really nice, so I extracted it from the full Kanata config that was kindly shared along with the demonstration. (Thanks a lot, Chris!)

Here is the layout that I would like to use:

keymap-drawer can parse a Kanata config and render it as an SVG.

The configuration wasn’t as straightforward as I initially thought. Here are the notes:

Preparations#

Kanata is not on the official Fedora Repos. There is a community maintained copr, but I prefer to build it directly in that case.

I already installed rustup and configured it. In case that needs to be done:

sudo dnf install rustup gcc
rustup-init -y
source "$HOME/.cargo/env"

Install Kanata#

rustup update stable
cargo install kanata
sudo install -m 755 ~/.cargo/bin/kanata /usr/local/bin/kanata

It is important to use install on Fedora instead of moving and chowning the file because of SELinux. When moving the executable from the home dir, the SELinux label user_home_t stays on the file and systemd refuses to start it with a Permission denied error.

sudo restorecon -v /usr/local/bin/kanata

fixes that.

Kanata needs the uinput module, so we make sure it is loaded:

echo uinput | sudo tee /etc/modules-load.d/uinput.conf
sudo modprobe uinput

I want Kanata to be started as a global and not as a user service, but I don’t want it to be running as root. So we need to add a user (kanata), a group (uinput), and setup the permissions for the /dev/uinput device accordingly.

sudo groupadd --system uinput

sudo useradd --system --no-create-home --shell /usr/sbin/nologin --groups input,uinput kanata

echo 'KERNEL=="uinput", MODE="0660", GROUP="uinput", OPTIONS+="static_node=uinput", RUN+="/usr/bin/setfacl -m g:uinput:rw /dev/uinput"' \
  | sudo tee /etc/udev/rules.d/99-uinput.rules

sudo udevadm control --reload
sudo udevadm trigger --name-match=uinput

Somehow the GROUP="uinput" tag wasn’t enough, so I had to add the setfacl command to add that rule.

The configuration#

;; Kanata config: Caps Lock as symbols and navigation layer

(defcfg
  process-unmapped-keys yes
)

(defsrc
  grv  1    2    3    4    5    6    7    8    9    0    -    =    bspc
  tab  q    w    e    r    t    y    u    i    o    p    [    ]
  caps a    s    d    f    g    h    j    k    l    ;    '    #    ret
  lsft <    z    x    c    v    b    n    m    ,    .    /    rsft
  lctl lmet lalt           spc            ralt rmet cmp  rctl
)

(defalias
  sym (layer-while-held symbols)
)

(deflayer base
  _    _    _    _    _    _    _    _    _    _    _    _    _    _
  _    _    _    _    _    _    _    _    _    _    _    _    _
  @sym _    _    _    _    _    _    _    _    _    _    _    _    _
  _    _    _    _    _    _    _    _    _    _    _    _    _
  _    _    _              _              _    _    _    _
)

(deflayer symbols
  _    f1   f2   f3   f4   f5   f6   f7   f8   f9   f10  f11  f12  del
  _    esc  tab  _    _    _    pgup home up   end  del  brk  prnt
  _    lalt lmet lsft lctl _    pgdn left down rght bspc _    _    _
  _    _    _    _    _    _    mute vold volu _    _    _    _
  pp   _    prev           ret            next _    _    _
)

systemd service#

[Unit]
Description=Kanata keyboard remapper
After=systemd-modules-load.service systemd-udevd.service

[Service]
Type=simple
User=kanata
Group=kanata
SupplementaryGroups=input uinput
ExecStart=/usr/local/bin/kanata --cfg /etc/kanata/kanata.kbd
Restart=always
RestartSec=3

NoNewPrivileges=yes
ProtectSystem=strict
ProtectHome=yes
PrivateTmp=yes

[Install]
WantedBy=multi-user.target

Reload systemd and enable the service.

sudo systemctl daemon-reload
sudo systemctl enable --now kanata
journalctl -u kanata -f

Update Kanata#

rustup update stable
cargo install kanata
sudo install -m 755 ~/.cargo/bin/kanata /usr/local/bin/kanata
kanata --cfg /etc/kanata/kanata.kbd --check && sudo systemctl restart kanata