adding functionality to commands

cmd/clusterctl/cmd/daemon_restart.go

@@ -10,8 +10,11 @@
 package cmd
 
 import (
-	"fmt"
+	"os"
+	"strconv"
+	"syscall"
 
+	"git.staur.ca/stobbsm/clustvirt/lib/log"
 	"github.com/spf13/cobra"
 )
 
@@ -22,7 +25,49 @@ var restartCmd = &cobra.Command{
 	Long: `Some configuration requires the daemon to restart itself.
 		This command sends the SIGUSR2 signal, telling the daemon to restart`,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("restart called")
+		log.Info("cmd.daemon.restart").
+			Msg("restarting daemon")
+		sPid, err := os.ReadFile(`/run/clustvirt.pid`)
+		if err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Msg("unable to restart")
+			os.Exit(1)
+		}
+		pid, err := strconv.Atoi(string(sPid))
+		if err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Msg("unable to restart")
+			os.Exit(1)
+		}
+		proc, err := os.FindProcess(pid)
+		if err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Msg("unable to restart")
+			os.Exit(1)
+		}
+		// make sure the process found is currently alive
+		if err = proc.Signal(syscall.Signal(0)); err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Int("PID", pid).
+				Msg("expected process doesn't seem to exist")
+		}
+		if err = proc.Signal(syscall.SIGUSR2); err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Msg("unable to restart")
+			os.Exit(1)
+		}
+		ps, err := proc.Wait()
+		if err != nil {
+			log.Error("cmd.daemon.restart").
+				Err(err).
+				Msg("unable to restart")
+			os.Exit(1)
+		}
 	},
 }
 

daemon/control.go

@@ -0,0 +1,18 @@
+package daemon
+
+import (
+	"fmt"
+	"os"
+
+	"git.staur.ca/stobbsm/clustvirt/lib/log"
+)
+
+func Start() {
+	pid := pid()
+	if err := os.WriteFile(PIDFile, []byte(fmt.Sprint(pid)), 0666); err != nil {
+		log.Error("daemon.Start").
+			Err(err).
+			Send()
+		os.Exit(1)
+	}
+}

daemon/main.go

@@ -1,8 +1,9 @@
 package daemon
 
 import (
-	"fmt"
+	"context"
 	"os"
+	"syscall"
 
 	"git.staur.ca/stobbsm/clustvirt/lib/log"
 )
@@ -17,16 +18,44 @@ func init() {
 	PIDFile = RunPath + `clustvirt.pid`
 }
 
-func Start() {
-	pid := pid()
-	if err := os.WriteFile(PIDFile, []byte(fmt.Sprint(pid)), 0666); err != nil {
-		log.Error("daemon.Start").
-			Err(err).
-			Send()
-		os.Exit(1)
-	}
-}
-
 func pid() int {
 	return os.Getpid()
 }
+
+func sigHandler(c <-chan os.Signal) context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		for {
+			sig := <-c
+			switch sig {
+			case syscall.SIGTERM:
+				log.Info("daemon.sigHandler").
+					Str("signal", "SIGTERM").
+					Msg("stopping clustvirt gracefully")
+				cancel()
+				<-ctx.Done()
+				os.Exit(0)
+			case syscall.SIGKILL:
+				log.Warn("daemon.sigHandler").
+					Str("signal", "SIGKILL").
+					Msg("killed. avenge me...")
+				os.Exit(1)
+			case syscall.SIGUSR1:
+				log.Info("daemon.sigHandler").
+					Str("signal", "SIGUSR1").
+					Msg("reloading configuration")
+			// TODO: Reload the application configuration here
+			case syscall.SIGUSR2:
+				log.Info("daemon.sigHandler").
+					Str("signal", "SIGUSR2").
+					Msg("restarting...")
+				// TODO: implement restart logic here
+			default:
+				log.Warn("daemon.sigHandler").
+					Str("signal", sig.String()).
+					Msg("unhandled signal recieved")
+			}
+		}
+	}()
+	return ctx
+}