1 files changed, 256 insertions, 0 deletions
diff --git a/runsc/cli/main.go b/runsc/cli/main.go
new file mode 100644
index 000000000..bca015db5
--- /dev/null
+++ b/runsc/cli/main.go
@@ -0,0 +1,256 @@
+// Copyright 2018 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 cli is the main entrypoint for runsc.
+package cli
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/google/subcommands"
+	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/refs"
+	"gvisor.dev/gvisor/pkg/sentry/platform"
+	"gvisor.dev/gvisor/runsc/cmd"
+	"gvisor.dev/gvisor/runsc/config"
+	"gvisor.dev/gvisor/runsc/flag"
+	"gvisor.dev/gvisor/runsc/specutils"
+)
+
+var (
+	// Although these flags are not part of the OCI spec, they are used by
+	// Docker, and thus should not be changed.
+	// TODO(gvisor.dev/issue/193): support systemd cgroups
+	systemdCgroup = flag.Bool("systemd-cgroup", false, "Use systemd for cgroups. NOT SUPPORTED.")
+	showVersion   = flag.Bool("version", false, "show version and exit.")
+
+	// These flags are unique to runsc, and are used to configure parts of the
+	// system that are not covered by the runtime spec.
+
+	// Debugging flags.
+	logFD      = flag.Int("log-fd", -1, "file descriptor to log to.  If set, the 'log' flag is ignored.")
+	debugLogFD = flag.Int("debug-log-fd", -1, "file descriptor to write debug logs to.  If set, the 'debug-log-dir' flag is ignored.")
+	panicLogFD = flag.Int("panic-log-fd", -1, "file descriptor to write Go's runtime messages.")
+)
+
+// Main is the main entrypoint.
+func Main(version string) {
+	// Help and flags commands are generated automatically.
+	help := cmd.NewHelp(subcommands.DefaultCommander)
+	help.Register(new(cmd.Syscalls))
+	subcommands.Register(help, "")
+	subcommands.Register(subcommands.FlagsCommand(), "")
+
+	// Installation helpers.
+	const helperGroup = "helpers"
+	subcommands.Register(new(cmd.Install), helperGroup)
+	subcommands.Register(new(cmd.Uninstall), helperGroup)
+
+	// Register user-facing runsc commands.
+	subcommands.Register(new(cmd.Checkpoint), "")
+	subcommands.Register(new(cmd.Create), "")
+	subcommands.Register(new(cmd.Delete), "")
+	subcommands.Register(new(cmd.Do), "")
+	subcommands.Register(new(cmd.Events), "")
+	subcommands.Register(new(cmd.Exec), "")
+	subcommands.Register(new(cmd.Gofer), "")
+	subcommands.Register(new(cmd.Kill), "")
+	subcommands.Register(new(cmd.List), "")
+	subcommands.Register(new(cmd.Pause), "")
+	subcommands.Register(new(cmd.PS), "")
+	subcommands.Register(new(cmd.Restore), "")
+	subcommands.Register(new(cmd.Resume), "")
+	subcommands.Register(new(cmd.Run), "")
+	subcommands.Register(new(cmd.Spec), "")
+	subcommands.Register(new(cmd.State), "")
+	subcommands.Register(new(cmd.Start), "")
+	subcommands.Register(new(cmd.Wait), "")
+
+	// Register internal commands with the internal group name. This causes
+	// them to be sorted below the user-facing commands with empty group.
+	// The string below will be printed above the commands.
+	const internalGroup = "internal use only"
+	subcommands.Register(new(cmd.Boot), internalGroup)
+	subcommands.Register(new(cmd.Debug), internalGroup)
+	subcommands.Register(new(cmd.Gofer), internalGroup)
+	subcommands.Register(new(cmd.Statefile), internalGroup)
+
+	config.RegisterFlags()
+
+	// All subcommands must be registered before flag parsing.
+	flag.Parse()
+
+	// Are we showing the version?
+	if *showVersion {
+		// The format here is the same as runc.
+		fmt.Fprintf(os.Stdout, "runsc version %s\n", version)
+		fmt.Fprintf(os.Stdout, "spec: %s\n", specutils.Version)
+		os.Exit(0)
+	}
+
+	// Create a new Config from the flags.
+	conf, err := config.NewFromFlags()
+	if err != nil {
+		cmd.Fatalf(err.Error())
+	}
+
+	// TODO(gvisor.dev/issue/193): support systemd cgroups
+	if *systemdCgroup {
+		fmt.Fprintln(os.Stderr, "systemd cgroup flag passed, but systemd cgroups not supported. See gvisor.dev/issue/193")
+		os.Exit(1)
+	}
+
+	var errorLogger io.Writer
+	if *logFD > -1 {
+		errorLogger = os.NewFile(uintptr(*logFD), "error log file")
+
+	} else if conf.LogFilename != "" {
+		// We must set O_APPEND and not O_TRUNC because Docker passes
+		// the same log file for all commands (and also parses these
+		// log files), so we can't destroy them on each command.
+		var err error
+		errorLogger, err = os.OpenFile(conf.LogFilename, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
+		if err != nil {
+			cmd.Fatalf("error opening log file %q: %v", conf.LogFilename, err)
+		}
+	}
+	cmd.ErrorLogger = errorLogger
+
+	if _, err := platform.Lookup(conf.Platform); err != nil {
+		cmd.Fatalf("%v", err)
+	}
+
+	// Sets the reference leak check mode. Also set it in config below to
+	// propagate it to child processes.
+	refs.SetLeakMode(conf.ReferenceLeak)
+
+	// Set up logging.
+	if conf.Debug {
+		log.SetLevel(log.Debug)
+	}
+
+	// Logging will include the local date and time via the time package.
+	//
+	// On first use, time.Local initializes the local time zone, which
+	// involves opening tzdata files on the host. Since this requires
+	// opening host files, it must be done before syscall filter
+	// installation.
+	//
+	// Generally there will be a log message before filter installation
+	// that will force initialization, but force initialization here in
+	// case that does not occur.
+	_ = time.Local.String()
+
+	subcommand := flag.CommandLine.Arg(0)
+
+	var e log.Emitter
+	if *debugLogFD > -1 {
+		f := os.NewFile(uintptr(*debugLogFD), "debug log file")
+
+		e = newEmitter(conf.DebugLogFormat, f)
+
+	} else if conf.DebugLog != "" {
+		f, err := specutils.DebugLogFile(conf.DebugLog, subcommand, "" /* name */)
+		if err != nil {
+			cmd.Fatalf("error opening debug log file in %q: %v", conf.DebugLog, err)
+		}
+		e = newEmitter(conf.DebugLogFormat, f)
+
+	} else {
+		// Stderr is reserved for the application, just discard the logs if no debug
+		// log is specified.
+		e = newEmitter("text", ioutil.Discard)
+	}
+
+	if *panicLogFD > -1 || *debugLogFD > -1 {
+		fd := *panicLogFD
+		if fd < 0 {
+			fd = *debugLogFD
+		}
+		// Quick sanity check to make sure no other commands get passed
+		// a log fd (they should use log dir instead).
+		if subcommand != "boot" && subcommand != "gofer" {
+			cmd.Fatalf("flags --debug-log-fd and --panic-log-fd should only be passed to 'boot' and 'gofer' command, but was passed to %q", subcommand)
+		}
+
+		// If we are the boot process, then we own our stdio FDs and can do what we
+		// want with them. Since Docker and Containerd both eat boot's stderr, we
+		// dup our stderr to the provided log FD so that panics will appear in the
+		// logs, rather than just disappear.
+		if err := syscall.Dup3(fd, int(os.Stderr.Fd()), 0); err != nil {
+			cmd.Fatalf("error dup'ing fd %d to stderr: %v", fd, err)
+		}
+	} else if conf.AlsoLogToStderr {
+		e = &log.MultiEmitter{e, newEmitter(conf.DebugLogFormat, os.Stderr)}
+	}
+
+	log.SetTarget(e)
+
+	log.Infof("***************************")
+	log.Infof("Args: %s", os.Args)
+	log.Infof("Version %s", version)
+	log.Infof("PID: %d", os.Getpid())
+	log.Infof("UID: %d, GID: %d", os.Getuid(), os.Getgid())
+	log.Infof("Configuration:")
+	log.Infof("\t\tRootDir: %s", conf.RootDir)
+	log.Infof("\t\tPlatform: %v", conf.Platform)
+	log.Infof("\t\tFileAccess: %v, overlay: %t", conf.FileAccess, conf.Overlay)
+	log.Infof("\t\tNetwork: %v, logging: %t", conf.Network, conf.LogPackets)
+	log.Infof("\t\tStrace: %t, max size: %d, syscalls: %s", conf.Strace, conf.StraceLogSize, conf.StraceSyscalls)
+	log.Infof("\t\tVFS2 enabled: %v", conf.VFS2)
+	log.Infof("***************************")
+
+	if conf.TestOnlyAllowRunAsCurrentUserWithoutChroot {
+		// SIGTERM is sent to all processes if a test exceeds its
+		// timeout and this case is handled by syscall_test_runner.
+		log.Warningf("Block the TERM signal. This is only safe in tests!")
+		signal.Ignore(syscall.SIGTERM)
+	}
+
+	// Call the subcommand and pass in the configuration.
+	var ws syscall.WaitStatus
+	subcmdCode := subcommands.Execute(context.Background(), conf, &ws)
+	if subcmdCode == subcommands.ExitSuccess {
+		log.Infof("Exiting with status: %v", ws)
+		if ws.Signaled() {
+			// No good way to return it, emulate what the shell does. Maybe raise
+			// signal to self?
+			os.Exit(128 + int(ws.Signal()))
+		}
+		os.Exit(ws.ExitStatus())
+	}
+	// Return an error that is unlikely to be used by the application.
+	log.Warningf("Failure to execute command, err: %v", subcmdCode)
+	os.Exit(128)
+}
+
+func newEmitter(format string, logFile io.Writer) log.Emitter {
+	switch format {
+	case "text":
+		return log.GoogleEmitter{&log.Writer{Next: logFile}}
+	case "json":
+		return log.JSONEmitter{&log.Writer{Next: logFile}}
+	case "json-k8s":
+		return log.K8sJSONEmitter{&log.Writer{Next: logFile}}
+	}
+	cmd.Fatalf("invalid log format %q, must be 'text', 'json', or 'json-k8s'", format)
+	panic("unreachable")
+}