audittail: React to SIGINT (#17)

The kubelet uses SIGINT to trigger shutdown of pods, this makes sure we
can appropriately react to it.

Signed-off-by: Juan Antonio Osorio <[email protected]>

cmds/audittail/cmd/root.go

@@ -35,6 +35,10 @@ const (
 // rootCmd represents the base command when called without any subcommands.
 var rootCmd = NewRootCmd()
 
+func GetCmd() *cobra.Command {
+	return rootCmd
+}
+
 func NewRootCmd() *cobra.Command {
 	c := &cobra.Command{
 		Use:   "audittail",

cmds/audittail/cmd/root_test.go

@@ -237,3 +237,10 @@ func TestFileTrailerUnknownErrorWhenTailing(t *testing.T) {
 	err := ft.tailFile(context.Background())
 	require.Error(t, err, "unexpected success")
 }
+
+func TestRootCmdSingletonGet(t *testing.T) {
+	t.Parallel()
+
+	c := GetCmd()
+	require.Equal(t, &rootCmd, &c, "GetCmd() should return the rootCmd singleton")
+}

cmds/audittail/main.go

@@ -16,14 +16,42 @@ limitations under the License.
 package main
 
 import (
+	"context"
 	"os"
+	"os/signal"
 
 	"github.com/metal-toolbox/auditevent/cmds/audittail/cmd"
 )
 
-func main() {
-	c := cmd.NewRootCmd()
-	if err := c.Execute(); err != nil {
-		os.Exit(1)
+func runCommand() int {
+	ctx := context.Background()
+
+	// trap Ctrl+C and call cancel on the context
+	ctx, cancel := context.WithCancel(ctx)
+
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+
+	defer func() {
+		signal.Stop(c)
+		cancel()
+	}()
+
+	go func() {
+		select {
+		case <-c:
+			cancel()
+		case <-ctx.Done():
+		}
+	}()
+
+	if err := cmd.GetCmd().ExecuteContext(ctx); err != nil {
+		return 1
 	}
+
+	return 0
+}
+
+func main() {
+	os.Exit(runCommand())
 }