Add podman machine events

Signed-off-by: Jhon Honce <jhonce@redhat.com>

1 files changed, 127 insertions, 5 deletions

diff --git a/cmd/podman/machine/machine.go b/cmd/podman/machine/machine.go
index d3775f022..4c566b11f 100644
--- a/cmd/podman/machine/machine.go
+++ b/cmd/podman/machine/machine.go
@@ -4,25 +4,39 @@
 package machine
 
 import (
+	"errors"
+	"net"
+	"os"
+	"path/filepath"
+	"regexp"
 	"strings"
+	"sync"
+	"time"
 
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/containers/podman/v4/cmd/podman/validate"
+	"github.com/containers/podman/v4/libpod/events"
 	"github.com/containers/podman/v4/pkg/machine"
+	"github.com/containers/podman/v4/pkg/util"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
 var (
-	noOp = func(cmd *cobra.Command, args []string) error {
-		return nil
-	}
+	// Pull in configured json library
+	json = registry.JSONLibrary()
+
+	sockPaths     []string   // Paths to unix domain sockets for publishing
+	openEventSock sync.Once  // Singleton support for opening sockets as needed
+	sockets       []net.Conn // Opened sockets, if any
+
 	// Command: podman _machine_
 	machineCmd = &cobra.Command{
 		Use:                "machine",
 		Short:              "Manage a virtual machine",
 		Long:               "Manage a virtual machine. Virtual machines are used to run Podman.",
-		PersistentPreRunE:  noOp,
-		PersistentPostRunE: noOp,
+		PersistentPreRunE:  initMachineEvents,
+		PersistentPostRunE: closeMachineEvents,
 		RunE:               validate.SubCommandExists,
 	}
 )
@@ -64,3 +78,111 @@ func getMachines(toComplete string) ([]string, cobra.ShellCompDirective) {
 	}
 	return suggestions, cobra.ShellCompDirectiveNoFileComp
 }
+
+func initMachineEvents(cmd *cobra.Command, _ []string) error {
+	logrus.Debugf("Called machine %s.PersistentPreRunE(%s)", cmd.Name(), strings.Join(os.Args, " "))
+
+	sockPaths, err := resolveEventSock()
+	if err != nil {
+		return err
+	}
+
+	// No sockets found, so no need to publish events...
+	if len(sockPaths) == 0 {
+		return nil
+	}
+
+	for _, path := range sockPaths {
+		conn, err := (&net.Dialer{}).DialContext(registry.Context(), "unix", path)
+		if err != nil {
+			logrus.Warnf("Failed to open event socket %q: %v", path, err)
+			continue
+		}
+		logrus.Debugf("Machine event socket %q found", path)
+		sockets = append(sockets, conn)
+	}
+	return nil
+}
+
+func resolveEventSock() ([]string, error) {
+	// Used mostly for testing
+	if sock, found := os.LookupEnv("PODMAN_MACHINE_EVENTS_SOCK"); found {
+		return []string{sock}, nil
+	}
+
+	xdg, err := util.GetRuntimeDir()
+	if err != nil {
+		logrus.Warnf("Failed to get runtime dir, machine events will not be published: %s", err)
+		return nil, nil
+	}
+
+	re := regexp.MustCompile(`machine_events.*\.sock`)
+	sockPaths := make([]string, 0)
+	fn := func(path string, info os.DirEntry, err error) error {
+		switch {
+		case err != nil:
+			return err
+		case info.IsDir():
+			return nil
+		case info.Type() != os.ModeSocket:
+			return nil
+		case !re.MatchString(info.Name()):
+			return nil
+		}
+
+		logrus.Debugf("Machine events will be published on: %q", path)
+		sockPaths = append(sockPaths, path)
+		return nil
+	}
+
+	if err := filepath.WalkDir(filepath.Join(xdg, "podman"), fn); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return sockPaths, nil
+}
+
+func newMachineEvent(status events.Status, event events.Event) {
+	openEventSock.Do(func() {
+		// No sockets where found, so no need to publish events...
+		if len(sockPaths) == 0 {
+			return
+		}
+
+		for _, path := range sockPaths {
+			conn, err := (&net.Dialer{}).DialContext(registry.Context(), "unix", path)
+			if err != nil {
+				logrus.Warnf("Failed to open event socket %q: %v", path, err)
+				continue
+			}
+			logrus.Debugf("Machine event socket %q found", path)
+			sockets = append(sockets, conn)
+		}
+	})
+
+	event.Status = status
+	event.Time = time.Now()
+	event.Type = events.Machine
+
+	payload, err := json.Marshal(event)
+	if err != nil {
+		logrus.Errorf("Unable to format machine event: %q", err)
+		return
+	}
+
+	for _, sock := range sockets {
+		if _, err := sock.Write(payload); err != nil {
+			logrus.Errorf("Unable to write machine event: %q", err)
+		}
+	}
+}
+
+func closeMachineEvents(cmd *cobra.Command, _ []string) error {
+	logrus.Debugf("Called machine %s.PersistentPostRunE(%s)", cmd.Name(), strings.Join(os.Args, " "))
+	for _, sock := range sockets {
+		_ = sock.Close()
+	}
+	return nil
+}