Refactor slow activities from nm-dispatcher script into separate listener service

tailscale/rootfs/etc/NetworkManager/dispatcher.d/protect-subnets

@@ -3,36 +3,19 @@
 export LOG_FD
 # The shebang 'with-contenv-merge' above is identical with 'with-contenv', but doesn't clear the current environment containing the dispatcher variables
 
-# Redirect outputs to the log (&2 is already set up as pipe by s6)
-exec 1>&2
-if [[ "${LOG_FD:-}" =~ ^[0-9]+$ ]]; then
-  eval "exec ${LOG_FD}>&1" || true
-fi
+readonly NM_DISPATCHER_LISTENER_QUEUE=/run/nm-dispatcher-listener-queue
 
-function halt-app() {
-  bashio::log.error "Failed to protect subnet routes. Halting app to prevent network loss."
-  echo -n 1 > /run/s6-linux-init-container-results/exitcode
-  exec /run/s6/basedir/bin/halt
-}
+# Redirect outputs to the log (though &2 is already set up as pipe by s6)
+exec &> /proc/1/fd/1
+bashio::log.reinitialize_output
 
 case "${NM_DISPATCHER_ACTION}" in
-  up|down)
-    bashio::log.info "Handling Network Manager action ${DEVICE_IP_IFACE-} ${NM_DISPATCHER_ACTION}"
-    unprotect-subnet-routes
-    if ! protect-subnet-routes; then
-      # Better stop app than risking losing all network connections
-      halt-app
-    fi
-    ;;
-  dhcp4-change|dhcp6-change)
-    # Do anything only when the addresses are really changed
-    if [[ "$(unprotect-subnet-routes test)" != "$(protect-subnet-routes test)" ]]; then
-      bashio::log.info "Handling Network Manager action ${DEVICE_IP_IFACE-} ${NM_DISPATCHER_ACTION}"
-      unprotect-subnet-routes
-      if ! protect-subnet-routes tested; then
-        # Better stop app than risking losing all network connections
-        halt-app
-      fi
+  up|down|dhcp4-change|dhcp6-change)
+    bashio::log.debug "Received Network Manager action ${DEVICE_IP_IFACE-} ${NM_DISPATCHER_ACTION}"
+    if ! echo "${DEVICE_IP_IFACE-} ${NM_DISPATCHER_ACTION}" > "${NM_DISPATCHER_LISTENER_QUEUE}"; then
+      bashio::log.fatal "Failed to send nm-dispatcher action to listener. Halting app to prevent network loss."
+      echo -n 1 > /run/s6-linux-init-container-results/exitcode
+      exec /run/s6/basedir/bin/halt
     fi
     ;;
   connectivity-change)

tailscale/rootfs/etc/s6-overlay/s6-rc.d/init-protect-subnets/down

@@ -0,0 +1 @@
+/etc/s6-overlay/s6-rc.d/init-protect-subnets/finish

tailscale/rootfs/etc/s6-overlay/s6-rc.d/init-protect-subnets/finish

@@ -0,0 +1,9 @@
+#!/command/with-contenv bashio
+# shellcheck shell=bash
+export LOG_FD
+# ==============================================================================
+# Home Assistant Community App: Tailscale
+# Remove subnet protection
+# ==============================================================================
+
+unprotect-subnet-routes

tailscale/rootfs/etc/s6-overlay/s6-rc.d/init-protect-subnets/run

@@ -0,0 +1,9 @@
+#!/command/with-contenv bashio
+# shellcheck shell=bash
+export LOG_FD
+# ==============================================================================
+# Home Assistant Community App: Tailscale
+# Prevent local subnets to be routed toward the tailnet
+# ==============================================================================
+
+protect-subnet-routes

tailscale/rootfs/etc/s6-overlay/s6-rc.d/init-protect-subnets/type

@@ -0,0 +1 @@
+oneshot

tailscale/rootfs/etc/s6-overlay/s6-rc.d/init-protect-subnets/up

@@ -0,0 +1 @@
+/etc/s6-overlay/s6-rc.d/init-protect-subnets/run

tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher-listener/finish

@@ -0,0 +1,32 @@
+#!/command/with-contenv bashio
+# shellcheck shell=bash
+export LOG_FD
+# ==============================================================================
+# Home Assistant Community App: Tailscale
+# Take down the S6 supervision tree when nm-dispatcher-listener fails
+# ==============================================================================
+readonly exit_code_container=$(</run/s6-linux-init-container-results/exitcode)
+readonly exit_code_service="${1}"
+readonly exit_code_signal="${2}"
+readonly service="nm-dispatcher-listener"
+
+readonly NM_DISPATCHER_LISTENER_QUEUE=/run/nm-dispatcher-listener-queue
+
+exec 4>&-
+rm -rf "${NM_DISPATCHER_LISTENER_QUEUE}"
+
+bashio::log.info \
+  "Service ${service} exited with code ${exit_code_service}" \
+  "(by signal ${exit_code_signal})"
+
+if [[ "${exit_code_service}" -eq 256 ]]; then
+  if [[ "${exit_code_signal}" -ne 15 && "${exit_code_container}" -eq 0 ]]; then
+    echo $((128 + $exit_code_signal)) > /run/s6-linux-init-container-results/exitcode
+  fi
+  [[ "${exit_code_signal}" -eq 15 ]] && exec /run/s6/basedir/bin/halt
+elif [[ "${exit_code_service}" -ne 0 ]]; then
+  if [[ "${exit_code_container}" -eq 0 ]]; then
+    echo "${exit_code_service}" > /run/s6-linux-init-container-results/exitcode
+  fi
+  exec /run/s6/basedir/bin/halt
+fi

tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher-listener/notification-fd

@@ -0,0 +1 @@
+3

tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher-listener/run

@@ -0,0 +1,52 @@
+#!/command/with-contenv bashio
+# shellcheck shell=bash
+export LOG_FD
+# ==============================================================================
+# Home Assistant Community App: Tailscale
+# Runs the nm-dispatcher-listener service
+# ==============================================================================
+
+readonly NM_DISPATCHER_LISTENER_QUEUE=/run/nm-dispatcher-listener-queue
+
+declare action
+declare subnet_routes_to_unprotect
+declare subnet_routes_to_protect
+
+mkfifo "${NM_DISPATCHER_LISTENER_QUEUE}"
+
+# Pin it to prevent closing it by other processes
+exec 4<>"${NM_DISPATCHER_LISTENER_QUEUE}"
+
+# We need to delay the starting of the dependent services until listener queue is created
+echo "" >&3
+exec 3>&-
+
+while IFS= read -r -u 4 action
+do
+  case "${action}" in
+  *up|*down)
+    bashio::log.info "Handling Network Manager action ${action}"
+    unprotect-subnet-routes
+    bashio::try protect-subnet-routes
+    if bashio::try.failed; then
+      bashio::exit.nok "Failed to protect subnet routes. Halting app to prevent network loss."
+    fi
+    ;;
+  *dhcp4-change|*dhcp6-change)
+    # Do anything only when the addresses are really changed
+    subnet_routes_to_unprotect="$(unprotect-subnet-routes test)"
+    subnet_routes_to_protect="$(protect-subnet-routes test)"
+    if ! bashio::var.equals "${subnet_routes_to_unprotect}" "${subnet_routes_to_protect}"; then
+      bashio::log.info "Handling Network Manager action ${action}"
+      unprotect-subnet-routes
+      bashio::try protect-subnet-routes tested
+      if bashio::try.failed; then
+        bashio::exit.nok "Failed to protect subnet routes. Halting app to prevent network loss."
+      fi
+    fi
+    ;;
+  *)
+    bashio::exit.nok "Unknown Network Manager action ${action}"
+    ;;
+  esac
+done

tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher-listener/type

@@ -0,0 +1 @@
+longrun

tailscale/rootfs/etc/s6-overlay/s6-rc.d/protect-subnets/finish → tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher/finish

@@ -3,21 +3,19 @@
 export LOG_FD
 # ==============================================================================
 # Home Assistant Community App: Tailscale
-# Take down the S6 supervision tree when protect-subnets fails
+# Take down the S6 supervision tree when nm-dispatcher fails
 # ==============================================================================
 readonly exit_code_container=$(</run/s6-linux-init-container-results/exitcode)
 readonly exit_code_service="${1}"
 readonly exit_code_signal="${2}"
-readonly service="protect-subnets"
-
-unprotect-subnet-routes
+readonly service="nm-dispatcher"
 
 bashio::log.info \
   "Service ${service} exited with code ${exit_code_service}" \
   "(by signal ${exit_code_signal})"
 
 if [[ "${exit_code_service}" -eq 256 ]]; then
-  if [[ "${exit_code_container}" -eq 0 ]]; then
+  if [[ "${exit_code_signal}" -ne 15 && "${exit_code_container}" -eq 0 ]]; then
     echo $((128 + $exit_code_signal)) > /run/s6-linux-init-container-results/exitcode
   fi
   [[ "${exit_code_signal}" -eq 15 ]] && exec /run/s6/basedir/bin/halt

tailscale/rootfs/etc/s6-overlay/s6-rc.d/protect-subnets/run → tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher/run

@@ -3,11 +3,9 @@
 export LOG_FD
 # ==============================================================================
 # Home Assistant Community App: Tailscale
-# Prevent local subnets to be routed toward the tailnet
+# Runs the nm-dispatcher service
 # ==============================================================================
 
-protect-subnet-routes
-
 # runs scripts in /etc/NetworkManager/dispatcher.d
 # --debug is used to prevent logging to syslog (HA cli)
 exec /usr/libexec/nm-dispatcher --persist --debug > /dev/null

tailscale/rootfs/etc/s6-overlay/s6-rc.d/nm-dispatcher/type

@@ -0,0 +1 @@
+longrun

tailscale/rootfs/etc/s6-overlay/s6-rc.d/protect-subnets/type

@@ -1 +1 @@
-longrun
+bundle