river: Change to runit-managed user service

Switching to runit (and turnstiled, which in turn activates user-local
runit service supervision) we can now have river run supervised by our
service manager quite easily.

We make use of this, but have to take care to export the
river-established wayland variables (DISPLAY, WAYLAND_DISPLAY) back into
the user environment for other processes since river will not be the
one responsible for spawning them anymore.

On finishing the service (i.e. exiting the process), we ensure
that the variables get removed from the environment again so it is not
polluted in the future.

Additionally, we load the (default for void runit) 'turnstile-ready'
service which can define core user services that need to exist before
others on login, and the session-local dbus service which river and
other programs will make use of. It is marked as essential with
turnstile-ready.

desktop/.config/river/init

@@ -1,8 +1,14 @@
 #!/usr/bin/env sh
 
+# turnstiled user service setup
+if [ -d "$TURNSTILE_ENV_DIR" ]; then
+    echo "$DISPLAY" >"$TURNSTILE_ENV_DIR/DISPLAY"
+    echo "$WAYLAND_DISPLAY" >"$TURNSTILE_ENV_DIR/WAYLAND_DISPLAY"
+fi
+
 mod="Mod4"
 modemod="Mod1"
-term=${TERMINAL:-foot}
+term=${TERMINAL:-wezterm}
 time_to_lockscreen=300
 time_to_screendim=600
 time_to_suspend=900

services/sv/dbus/log/run

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec vlogger -t dbus_user -p daemon

services/sv/dbus/run

@@ -0,0 +1 @@
+/usr/share/examples/turnstile/dbus.run

services/sv/river/finish

@@ -0,0 +1,6 @@
+#!/usr/bin/env sh
+
+if [ -d "$TURNSTILE_ENV_DIR" ]; then
+    [ -r "$TURNSTILE_ENV_DIR/DISPLAY" ] && rm "$TURNSTILE_ENV_DIR/DISPLAY"
+    [ -r "$TURNSTILE_ENV_DIR/WAYLAND_DISPLAY" ] && rm "$TURNSTILE_ENV_DIR/WAYLAND_DISPLAY"
+fi

services/sv/river/log/run

@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+
+exec vlogger -t river -p daemon

services/sv/river/run

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+[ -r ./conf ] && . ./conf
+
+if [ -d "$TURNSTILE_ENV_DIR" ]; then
+    echo "$HOME/.local/bin:$PATH" > "$TURNSTILE_ENV_DIR/PATH"
+fi
+
+exec 2>&1
+exec chpst -e "$TURNSTILE_ENV_DIR" river -log-level warning

services/sv/turnstile-ready/conf

@@ -0,0 +1 @@
+core_services="dbus"

services/sv/turnstile-ready/run

@@ -0,0 +1,5 @@
+#!/bin/sh
+[ -r ./conf ] && . ./conf
+[ -n "$core_services" ] && SVDIR=".." sv start $core_services
+[ -p "/run/turnstiled/1000/ready" ] && printf "/home/marty/.local/state/service/turnstile-ready" > "/run/turnstiled/1000/ready"
+exec pause