Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 111 insertions, 0 deletions

diff --git a/runsc/cmd/events.go b/runsc/cmd/events.go
new file mode 100644
index 000000000..afd42c2f2
--- /dev/null
+++ b/runsc/cmd/events.go
@@ -0,0 +1,111 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cmd
+
+import (
+	"encoding/json"
+	"os"
+	"time"
+
+	"context"
+	"flag"
+	"github.com/google/subcommands"
+	"gvisor.googlesource.com/gvisor/pkg/log"
+	"gvisor.googlesource.com/gvisor/runsc/boot"
+	"gvisor.googlesource.com/gvisor/runsc/sandbox"
+)
+
+// Events implements subcommands.Command for the "events" command.
+type Events struct {
+	// The interval between stats reporting.
+	intervalSec int
+	// If true, events will print a single group of stats and exit.
+	stats bool
+}
+
+// Name implements subcommands.Command.Name.
+func (*Events) Name() string {
+	return "events"
+}
+
+// Synopsis implements subcommands.Command.Synopsis.
+func (*Events) Synopsis() string {
+	return "display container events such as OOM notifications, cpu, memory, and IO usage statistics"
+}
+
+// Usage implements subcommands.Command.Usage.
+func (*Events) Usage() string {
+	return `<container-id>
+
+Where "<container-id>" is the name for the instance of the container.
+
+The events command displays information about the container. By default the
+information is displayed once every 5 seconds.
+
+OPTIONS:
+`
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (evs *Events) SetFlags(f *flag.FlagSet) {
+	f.IntVar(&evs.intervalSec, "interval", 5, "set the stats collection interval, in seconds")
+	f.BoolVar(&evs.stats, "stats", false, "display the container's stats then exit")
+}
+
+// Execute implements subcommands.Command.Execute.
+func (evs *Events) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if f.NArg() != 1 {
+		f.Usage()
+		return subcommands.ExitUsageError
+	}
+
+	id := f.Arg(0)
+	conf := args[0].(*boot.Config)
+
+	s, err := sandbox.Load(conf.RootDir, id)
+	if err != nil {
+		Fatalf("error loading sandox: %v", err)
+	}
+
+	// Repeatedly get stats from the container.
+	for {
+		// Get the event and print it as JSON.
+		ev, err := s.Event()
+		if err != nil {
+			log.Warningf("error getting events for sandbox: %v", err)
+		}
+		// err must be preserved because it is used below when breaking
+		// out of the loop.
+		b, err := json.Marshal(ev)
+		if err != nil {
+			log.Warningf("error while marshalling event %v: %v", ev, err)
+		} else {
+			os.Stdout.Write(b)
+		}
+
+		// If we're only running once, break. If we're only running
+		// once and there was an error, the command failed.
+		if evs.stats {
+			if err != nil {
+				return subcommands.ExitFailure
+			}
+			break
+		}
+
+		time.Sleep(time.Duration(evs.intervalSec) * time.Second)
+	}
+
+	return subcommands.ExitSuccess
+}