Feature: Reload config SIGUSR1

[nyarly]

It'd be very useful to me if Alacritty would reload its configuration on SIGUSR1 (as a first choice - other signals would be okay too)

My configuration management system (in this case home-manager) symlinks into a read-only mount. To do updates, I need to copy the file into place and alter that, which confuses the FS watch subsystem. With a signal, I could either trigger the update myself, or build my own fswatch tooling.

[nyarly]

I might have time to work on this over the holidays, but I'm by no means "claiming" this to work on.

[alarsyo]

Possibly related to #2237, and in the case of home-manager the simple solution discussed in the other issue would work: watching both the symlink in the original config path, and the actual file, not every symlink in the chain.

[ncfavier]

This would be useful to me, any hints on how it should be implemented?

My attempt seems to mostly work but sometimes makes alacritty freeze completely after SIGUSR1.

(I am not a Rust programmer)

[alarsyo]

@ncfavier your patch works great here, I couldn't get it to hang :/

could it be a problem with the config reload, not the handling of SIGUSR1 ?

Tested with:

alacritty --config-file config.yaml

and running this

#!/bin/sh

MY_PID=$1

while true; do
      ln -sf config1.yaml config.yaml
      kill -10 $MY_PID
      sleep 1
      ln -sf config2.yaml config.yaml
      kill -10 $MY_PID
      sleep 1
done

With two simple configuration files, changing font size between the two.

[ncfavier]

Moved it to a PR.

[ncfavier]

@nyarly does #5399 solve your initial problem?

[nyarly]

It might? I haven't had a chance to test a source-build of it, and it hasn't been released on my distro yet.

[ncfavier]

It hasn't been released at all.

[nyarly]

Huh. On Alactritty 0.8.0, my use case works now. I appreciate your work, but I think my specific issue was handled already.

For reference, I have:

#!/usr/bin/env fish

set config ~/.config/alacritty/alacritty.yml

set scheme solarized-light

if grep -q "^colors: [*]solarized-light" $config
  set scheme solarized-dark
end

# a script called: materialize-config $config
# inlined here:

test (count $argv) -eq 1; or exit 1
set -l path $argv[1]
test -L $path; and cp --remove-destination (readlink $path) $path
chmod u+w $path

sed -i.bak "s/^colors: *.*/colors: *$scheme/" $config

The materialize-config stuff is to address how home-manager works; honestly, it may be that I've done this once, and then started new terminals after that, so the watch issue isn't a problem until the next time I change my config in HM. I could probably also "materialize" this in a HM hook, since it has to happen if I'm going to change colorschemes anyway