Add podman machine events

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

cmd/podman/machine/init.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/libpod/events"
 	"github.com/containers/podman/v4/pkg/machine"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -145,11 +146,14 @@ func initMachine(cmd *cobra.Command, args []string) error {
 		// Finished = *,     err != nil  -  Exit with an error message
 		return err
 	}
+	newMachineEvent(events.Init, events.Event{Name: initOpts.Name})
 	fmt.Println("Machine init complete")
+
 	if now {
 		err = vm.Start(initOpts.Name, machine.StartOptions{})
 		if err == nil {
 			fmt.Printf("Machine %q started successfully\n", initOpts.Name)
+			newMachineEvent(events.Start, events.Event{Name: initOpts.Name})
 		}
 	} else {
 		extra := ""

cmd/podman/machine/inspect.go

@@ -4,7 +4,6 @@
 package machine
 
 import (
-	"encoding/json"
 	"os"
 
 	"github.com/containers/podman/v4/cmd/podman/common"

cmd/podman/machine/list.go

@@ -4,7 +4,6 @@
 package machine
 
 import (
-	"encoding/json"
 	"os"
 	"sort"
 	"strconv"

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 {
+	// Pull in configured json library
-		return nil
+	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,
+		PersistentPreRunE:  initMachineEvents,
-		PersistentPostRunE: noOp,
+		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
+}

cmd/podman/machine/rm.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/libpod/events"
 	"github.com/containers/podman/v4/pkg/machine"
 	"github.com/spf13/cobra"
 )
@@ -50,7 +51,7 @@ func init() {
 	flags.BoolVar(&destroyOptions.SaveImage, imageFlagName, false, "Do not delete the image file")
 }
 
-func rm(cmd *cobra.Command, args []string) error {
+func rm(_ *cobra.Command, args []string) error {
 	var (
 		err error
 		vm  machine.VM
@@ -83,5 +84,10 @@ func rm(cmd *cobra.Command, args []string) error {
 			return nil
 		}
 	}
-	return remove()
+	err = remove()
+	if err != nil {
+		return err
+	}
+	newMachineEvent(events.Remove, events.Event{Name: vmName})
+	return nil
 }

cmd/podman/machine/start.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 
 	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/libpod/events"
 	"github.com/containers/podman/v4/pkg/machine"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -31,7 +32,7 @@ func init() {
 	})
 }
 
-func start(cmd *cobra.Command, args []string) error {
+func start(_ *cobra.Command, args []string) error {
 	var (
 		err error
 		vm  machine.VM
@@ -62,5 +63,6 @@ func start(cmd *cobra.Command, args []string) error {
 		return err
 	}
 	fmt.Printf("Machine %q started successfully\n", vmName)
+	newMachineEvent(events.Start, events.Event{Name: vmName})
 	return nil
 }

cmd/podman/machine/stop.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 
 	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/libpod/events"
 	"github.com/containers/podman/v4/pkg/machine"
 	"github.com/spf13/cobra"
 )
@@ -49,5 +50,6 @@ func stop(cmd *cobra.Command, args []string) error {
 		return err
 	}
 	fmt.Printf("Machine %q stopped successfully\n", vmName)
+	newMachineEvent(events.Stop, events.Event{Name: vmName})
 	return nil
 }

cmd/podman/main.go

@@ -18,6 +18,7 @@ import (
 	_ "github.com/containers/podman/v4/cmd/podman/secrets"
 	_ "github.com/containers/podman/v4/cmd/podman/system"
 	_ "github.com/containers/podman/v4/cmd/podman/system/connection"
+	"github.com/containers/podman/v4/cmd/podman/validate"
 	_ "github.com/containers/podman/v4/cmd/podman/volumes"
 	"github.com/containers/podman/v4/pkg/domain/entities"
 	"github.com/containers/podman/v4/pkg/rootless"
@@ -64,8 +65,8 @@ func parseCommands() *cobra.Command {
 				c.Command.Hidden = true
 
 				// overwrite persistent pre/post function to skip setup
-				c.Command.PersistentPostRunE = noop
+				c.Command.PersistentPostRunE = validate.NoOp
-				c.Command.PersistentPreRunE = noop
+				c.Command.PersistentPreRunE = validate.NoOp
 				addCommand(c)
 				continue
 			}
@@ -120,7 +121,3 @@ func addCommand(c registry.CliCommand) {
 	c.Command.SetUsageTemplate(usageTemplate)
 	c.Command.DisableFlagsInUseLine = true
 }
-
-func noop(cmd *cobra.Command, args []string) error {
-	return nil
-}

cmd/podman/system/connection.go

@@ -7,18 +7,15 @@ import (
 )
 
 var (
-	// Skip creating engines since this command will obtain connection information to said engines
+	// ConnectionCmd skips creating engines (PersistentPreRunE/PersistentPostRunE are No-Op's) since
-	noOp = func(cmd *cobra.Command, args []string) error {
+	// sub-commands will obtain connection information to said engines
-		return nil
-	}
-
 	ConnectionCmd = &cobra.Command{
 		Use:                "connection",
-		Short:              "Manage remote ssh destinations",
+		Short:              "Manage remote API service destinations",
-		Long:               `Manage ssh destination information in podman configuration`,
+		Long:               `Manage remote API service destination information in podman configuration`,
-		PersistentPreRunE:  noOp,
+		PersistentPreRunE:  validate.NoOp,
 		RunE:               validate.SubCommandExists,
-		PersistentPostRunE: noOp,
+		PersistentPostRunE: validate.NoOp,
 		TraverseChildren:   false,
 	}
 )

cmd/podman/validate/noop.go

@@ -0,0 +1,9 @@
+package validate
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func NoOp(_ *cobra.Command, _ []string) error {
+	return nil
+}

libpod/events/config.go

@@ -17,6 +17,8 @@ const (
 	Journald EventerType = iota
 	// Null is a no-op events logger. It does not read or write events.
 	Null EventerType = iota
+	// Memory indicates the event logger will hold events in memory
+	Memory EventerType = iota
 )
 
 // Event describes the attributes of a libpod event
@@ -55,7 +57,7 @@ type Details struct {
 // EventerOptions describe options that need to be passed to create
 // an eventer
 type EventerOptions struct {
-	// EventerType describes whether to use journald or a file
+	// EventerType describes whether to use journald, file or memory
 	EventerType string
 	// LogFilePath is the path to where the log file should reside if using
 	// the file logger
@@ -110,6 +112,8 @@ const (
 	System Type = "system"
 	// Volume - event is related to volumes
 	Volume Type = "volume"
+	// Machine - event is related to machine VM's
+	Machine Type = "machine"
 
 	// Attach ...
 	Attach Status = "attach"

libpod/events/events.go

@@ -20,6 +20,8 @@ func (et EventerType) String() string {
 		return "file"
 	case Journald:
 		return "journald"
+	case Memory:
+		return "memory"
 	case Null:
 		return "none"
 	default:
@@ -34,6 +36,8 @@ func IsValidEventer(eventer string) bool {
 		return true
 	case Journald.String():
 		return true
+	case Memory.String():
+		return true
 	case Null.String():
 		return true
 	default:
@@ -41,7 +45,7 @@ func IsValidEventer(eventer string) bool {
 	}
 }
 
-// NewEvent creates a event struct and populates with
+// NewEvent creates an event struct and populates with
 // the given status and time.
 func NewEvent(status Status) Event {
 	return Event{
@@ -63,7 +67,7 @@ func (e *Event) ToJSONString() (string, error) {
 	return string(b), err
 }
 
-// ToHumanReadable returns human readable event as a formatted string
+// ToHumanReadable returns human-readable event as a formatted string
 func (e *Event) ToHumanReadable(truncate bool) string {
 	var humanFormat string
 	id := e.ID
@@ -90,7 +94,7 @@ func (e *Event) ToHumanReadable(truncate bool) string {
 		} else {
 			humanFormat = fmt.Sprintf("%s %s %s", e.Time, e.Type, e.Status)
 		}
-	case Volume:
+	case Volume, Machine:
 		humanFormat = fmt.Sprintf("%s %s %s %s", e.Time, e.Type, e.Status, e.Name)
 	}
 	return humanFormat
@@ -99,19 +103,19 @@ func (e *Event) ToHumanReadable(truncate bool) string {
 // NewEventFromString takes stringified json and converts
 // it to an event
 func newEventFromJSONString(event string) (*Event, error) {
-	e := Event{}
+	e := new(Event)
-	if err := json.Unmarshal([]byte(event), &e); err != nil {
+	if err := json.Unmarshal([]byte(event), e); err != nil {
 		return nil, err
 	}
-	return &e, nil
+	return e, nil
 }
 
-// ToString converts a Type to a string
+// String converts a Type to a string
 func (t Type) String() string {
 	return string(t)
 }
 
-// ToString converts a status to a string
+// String converts a status to a string
 func (s Status) String() string {
 	return string(s)
 }
@@ -123,6 +127,8 @@ func StringToType(name string) (Type, error) {
 		return Container, nil
 	case Image.String():
 		return Image, nil
+	case Machine.String():
+		return Machine, nil
 	case Network.String():
 		return Network, nil
 	case Pod.String():

libpod/events/events_linux.go

@@ -21,6 +21,8 @@ func NewEventer(options EventerOptions) (Eventer, error) {
 		return EventLogFile{options}, nil
 	case strings.ToUpper(Null.String()):
 		return NewNullEventer(), nil
+	case strings.ToUpper(Memory.String()):
+		return NewMemoryEventer(), nil
 	default:
 		return nil, errors.Errorf("unknown event logger type: %s", strings.ToUpper(options.EventerType))
 	}

libpod/events/memory.go

@@ -0,0 +1,49 @@
+package events
+
+import (
+	"context"
+)
+
+// EventMemory is the structure for event writing to a channel. It contains the eventer
+// options and the event itself.  Methods for reading and writing are also defined from it.
+type EventMemory struct {
+	options  EventerOptions
+	elements chan *Event
+}
+
+// Write event to memory queue
+func (e EventMemory) Write(event Event) (err error) {
+	e.elements <- &event
+	return
+}
+
+// Read event(s) from memory queue
+func (e EventMemory) Read(ctx context.Context, options ReadOptions) (err error) {
+	select {
+	case <-ctx.Done():
+		return
+	default:
+	}
+
+	select {
+	case event := <-e.elements:
+		options.EventChannel <- event
+	default:
+	}
+	return nil
+}
+
+// String returns eventer type
+func (e EventMemory) String() string {
+	return e.options.EventerType
+}
+
+// NewMemoryEventer returns configured MemoryEventer
+func NewMemoryEventer() Eventer {
+	return EventMemory{
+		options: EventerOptions{
+			EventerType: Memory.String(),
+		},
+		elements: make(chan *Event, 100),
+	}
+}

test/e2e/common_test.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"math/rand"
 	"net"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -1063,3 +1064,36 @@ func digShort(container, lookupName string, matchNames []string, p *PodmanTestIn
 	}
 	Fail("dns is not responding")
 }
+
+// WaitForFile to be created in defaultWaitTimeout seconds, returns false if file not created
+func WaitForFile(path string) (err error) {
+	until := time.Now().Add(time.Duration(defaultWaitTimeout) * time.Second)
+	for i := 1; time.Now().Before(until); i++ {
+		_, err = os.Stat(path)
+		switch {
+		case err == nil:
+			return nil
+		case errors.Is(err, os.ErrNotExist):
+			time.Sleep(time.Duration(i) * time.Second)
+		default:
+			return err
+		}
+	}
+	return err
+}
+
+// WaitForService blocks, waiting for some service listening on given host:port
+func WaitForService(address url.URL) {
+	// Wait for podman to be ready
+	var conn net.Conn
+	var err error
+	for i := 1; i <= 5; i++ {
+		conn, err = net.Dial("tcp", address.Host)
+		if err != nil {
+			// Podman not available yet...
+			time.Sleep(time.Duration(i) * time.Second)
+		}
+	}
+	Expect(err).ShouldNot(HaveOccurred())
+	conn.Close()
+}

test/e2e/system_service_test.go

@@ -122,22 +122,6 @@ var _ = Describe("podman system service", func() {
 	})
 })
 
-// WaitForService blocks, waiting for some service listening on given host:port
-func WaitForService(address url.URL) {
-	// Wait for podman to be ready
-	var conn net.Conn
-	var err error
-	for i := 1; i <= 5; i++ {
-		conn, err = net.Dial("tcp", address.Host)
-		if err != nil {
-			// Podman not available yet...
-			time.Sleep(time.Duration(i) * time.Second)
-		}
-	}
-	Expect(err).ShouldNot(HaveOccurred())
-	conn.Close()
-}
-
 // randomPort leans on the go net library to find an available port...
 func randomPort() string {
 	port, err := utils.GetRandomPort()