Add Usage controls

Add Usage controls and implement "usage/usagefd" commands.

PiperOrigin-RevId: 390507423

2 files changed, 94 insertions, 0 deletions

diff --git a/runsc/cmd/BUILD b/runsc/cmd/BUILD
index 031ddd57e..c5e32807d 100644
--- a/runsc/cmd/BUILD
+++ b/runsc/cmd/BUILD
@@ -36,6 +36,7 @@ go_library(
         "statefile.go",
         "symbolize.go",
         "syscalls.go",
+        "usage.go",
         "verity_prepare.go",
         "wait.go",
     ],
diff --git a/runsc/cmd/usage.go b/runsc/cmd/usage.go
new file mode 100644
index 000000000..d2aeafa28
--- /dev/null
+++ b/runsc/cmd/usage.go
@@ -0,0 +1,93 @@
+// Copyright 2021 The gVisor Authors.
+//
+// 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/google/subcommands"
+	"gvisor.dev/gvisor/runsc/config"
+	"gvisor.dev/gvisor/runsc/container"
+	"gvisor.dev/gvisor/runsc/flag"
+)
+
+// Usage implements subcommands.Command for the "usage" command.
+type Usage struct {
+	full bool
+	fd   bool
+}
+
+// Name implements subcommands.Command.Name.
+func (*Usage) Name() string {
+	return "usage"
+}
+
+// Synopsis implements subcommands.Command.Synopsis.
+func (*Usage) Synopsis() string {
+	return "Usage shows application memory usage across various categories in bytes."
+}
+
+// Usage implements subcommands.Command.Usage.
+func (*Usage) Usage() string {
+	return `usage [flags] <container id> - print memory usages to standard output.`
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (u *Usage) SetFlags(f *flag.FlagSet) {
+	f.BoolVar(&u.full, "full", false, "enumerate all usage by categories")
+	f.BoolVar(&u.fd, "fd", false, "retrieves a subset of usage through the established usage FD")
+}
+
+// Execute implements subcommands.Command.Execute.
+func (u *Usage) Execute(_ 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].(*config.Config)
+
+	cont, err := container.Load(conf.RootDir, container.FullID{ContainerID: id}, container.LoadOpts{})
+	if err != nil {
+		Fatalf("loading container: %v", err)
+	}
+
+	if !u.fd {
+		m, err := cont.Usage(u.full)
+		if err != nil {
+			Fatalf("usage failed: %v", err)
+		}
+		if err := json.NewEncoder(os.Stdout).Encode(m); err != nil {
+			Fatalf("Encode MemoryUsage failed: %v", err)
+		}
+	} else {
+		m, err := cont.UsageFD()
+		if err != nil {
+			Fatalf("usagefd failed: %v", err)
+		}
+
+		mapped, unknown, total, err := m.Fetch()
+		if err != nil {
+			Fatalf("Fetch memory usage failed: %v", err)
+		}
+
+		fmt.Printf("Mapped %v, Unknown %v, Total %v\n", mapped, unknown, total)
+	}
+	return subcommands.ExitSuccess
+}