Merge pull request #1790 from jessvalarezo/ctr-c-create

ctr: add container create cmd and config flag

cmd/ctr/commands/containers/containers.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/cmd/ctr/commands"
+	"github.com/containerd/containerd/cmd/ctr/commands/run"
 	"github.com/containerd/containerd/log"
 	"github.com/urfave/cli"
 )
@@ -20,6 +21,7 @@ var Command = cli.Command{
 	Usage:   "manage containers",
 	Aliases: []string{"c", "container"},
 	Subcommands: []cli.Command{
+		createCommand,
 		deleteCommand,
 		infoCommand,
 		listCommand,
@@ -27,6 +29,35 @@ var Command = cli.Command{
 	},
 }
 
+var createCommand = cli.Command{
+	Name:      "create",
+	Usage:     "create container",
+	ArgsUsage: "[flags] Image|RootFS CONTAINER",
+	Flags:     append(commands.SnapshotterFlags, run.ContainerFlags...),
+	Action: func(context *cli.Context) error {
+		var (
+			id  = context.Args().Get(1)
+			ref = context.Args().First()
+		)
+		if ref == "" {
+			return errors.New("image ref must be provided")
+		}
+		if id == "" {
+			return errors.New("container id must be provided")
+		}
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		_, err = run.NewContainer(ctx, client, context)
+		if err != nil {
+			return err
+		}
+		return nil
+	},
+}
+
 var listCommand = cli.Command{
 	Name:      "list",
 	Aliases:   []string{"ls"},
@@ -146,13 +177,13 @@ func deleteContainer(ctx context.Context, client *containerd.Client, id string,
 var setLabelsCommand = cli.Command{
 	Name:        "label",
 	Usage:       "set and clear labels for a container",
-	ArgsUsage:   "[flags] <name> [<key>=<value>, ...]",
+	ArgsUsage:   "[flags] CONTAINER [<key>=<value>, ...]",
 	Description: "set and clear labels for a container",
 	Flags:       []cli.Flag{},
 	Action: func(context *cli.Context) error {
 		containerID, labels := commands.ObjectWithLabelArgs(context)
 		if containerID == "" {
-			return errors.New("please specify a container")
+			return errors.New("container id must be provided")
 		}
 		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {

cmd/ctr/commands/run/run.go

@@ -3,7 +3,9 @@ package run
 import (
 	gocontext "context"
 	"encoding/csv"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"runtime"
 	"strings"
 
@@ -20,6 +22,62 @@ import (
 	"github.com/urfave/cli"
 )
 
+// ContainerFlags are cli flags specifying container options
+var ContainerFlags = []cli.Flag{
+	cli.StringFlag{
+		Name:  "config,c",
+		Usage: "path to the runtime-specific spec config file",
+	},
+	cli.StringFlag{
+		Name:  "checkpoint",
+		Usage: "provide the checkpoint digest to restore the container",
+	},
+	cli.StringFlag{
+		Name:  "cwd",
+		Usage: "specify the working directory of the process",
+	},
+	cli.StringSliceFlag{
+		Name:  "env",
+		Usage: "specify additional container environment variables (i.e. FOO=bar)",
+	},
+	cli.StringSliceFlag{
+		Name:  "label",
+		Usage: "specify additional labels (i.e. foo=bar)",
+	},
+	cli.StringSliceFlag{
+		Name:  "mount",
+		Usage: "specify additional container mount (ex: type=bind,src=/tmp,dest=/host,options=rbind:ro)",
+	},
+	cli.BoolFlag{
+		Name:  "net-host",
+		Usage: "enable host networking for the container",
+	},
+	cli.BoolFlag{
+		Name:  "read-only",
+		Usage: "set the containers filesystem as readonly",
+	},
+	cli.StringFlag{
+		Name:  "runtime",
+		Usage: "runtime name (io.containerd.runtime.v1.linux, io.containerd.runtime.v1.windows, io.containerd.runtime.v1.com.vmware.linux)",
+		Value: fmt.Sprintf("io.containerd.runtime.v1.%s", runtime.GOOS),
+	},
+	cli.BoolFlag{
+		Name:  "tty,t",
+		Usage: "allocate a TTY for the container",
+	},
+}
+
+func loadSpec(path string, s *specs.Spec) error {
+	raw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return errors.New("cannot load spec config file")
+	}
+	if err := json.Unmarshal(raw, s); err != nil {
+		return errors.New("decoding spec config file failed")
+	}
+	return nil
+}
+
 func withMounts(context *cli.Context) oci.SpecOpts {
 	return func(ctx gocontext.Context, client oci.Client, container *containers.Container, s *specs.Spec) error {
 		mounts := make([]specs.Mount, 0)
@@ -75,47 +133,10 @@ var Command = cli.Command{
 	Usage:     "run a container",
 	ArgsUsage: "[flags] Image|RootFS ID [COMMAND] [ARG...]",
 	Flags: append([]cli.Flag{
-		cli.BoolFlag{
-			Name:  "tty,t",
-			Usage: "allocate a TTY for the container",
-		},
-		cli.StringFlag{
-			Name:  "runtime",
-			Usage: "runtime name (io.containerd.runtime.v1.linux, io.containerd.runtime.v1.windows, io.containerd.runtime.v1.com.vmware.linux)",
-			Value: fmt.Sprintf("io.containerd.runtime.v1.%s", runtime.GOOS),
-		},
-		cli.BoolFlag{
-			Name:  "readonly",
-			Usage: "set the containers filesystem as readonly",
-		},
-		cli.BoolFlag{
-			Name:  "net-host",
-			Usage: "enable host networking for the container",
-		},
-		cli.StringSliceFlag{
-			Name:  "mount",
-			Usage: "specify additional container mount (ex: type=bind,src=/tmp,dst=/host,options=rbind:ro)",
-		},
-		cli.StringSliceFlag{
-			Name:  "env",
-			Usage: "specify additional container environment variables (i.e. FOO=bar)",
-		},
-		cli.StringSliceFlag{
-			Name:  "label",
-			Usage: "specify additional labels (foo=bar)",
-		},
 		cli.BoolFlag{
 			Name:  "rm",
 			Usage: "remove the container after running",
 		},
-		cli.StringFlag{
-			Name:  "checkpoint",
-			Usage: "provide the checkpoint digest to restore the container",
-		},
-		cli.StringFlag{
-			Name:  "cwd",
-			Usage: "specify the working directory of the process",
-		},
 		cli.BoolFlag{
 			Name:  "null-io",
 			Usage: "send all IO to /dev/null",
@@ -128,18 +149,18 @@ var Command = cli.Command{
 			Name:  "fifo-dir",
 			Usage: "directory used for storing IO FIFOs",
 		},
-	}, commands.SnapshotterFlags...),
+	}, append(commands.SnapshotterFlags, ContainerFlags...)...),
 	Action: func(context *cli.Context) error {
 		var (
 			err error
 
 			id     = context.Args().Get(1)
-			imageRef = context.Args().First()
+			ref    = context.Args().First()
 			tty    = context.Bool("tty")
 			detach = context.Bool("detach")
 		)
 
-		if imageRef == "" {
+		if ref == "" {
 			return errors.New("image ref must be provided")
 		}
 		if id == "" {
@@ -150,7 +171,7 @@ var Command = cli.Command{
 			return err
 		}
 		defer cancel()
-		container, err := newContainer(ctx, client, context)
+		container, err := NewContainer(ctx, client, context)
 		if err != nil {
 			return err
 		}
@@ -197,7 +218,6 @@ var Command = cli.Command{
 		if err != nil {
 			return err
 		}
-
 		if _, err := task.Delete(ctx); err != nil {
 			return err
 		}

cmd/ctr/commands/run/run_unix.go

@@ -22,7 +22,8 @@ func init() {
 	})
 }
 
-func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli.Context) (containerd.Container, error) {
+// NewContainer creates a new container
+func NewContainer(ctx gocontext.Context, client *containerd.Client, context *cli.Context) (containerd.Container, error) {
 	var (
 		ref  = context.Args().First()
 		id   = context.Args().Get(1)
@@ -40,8 +41,12 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 	var (
 		opts  []oci.SpecOpts
 		cOpts []containerd.NewContainerOpts
+		spec  containerd.NewContainerOpts
 	)
+	opts = append(opts, oci.WithEnv(context.StringSlice("env")))
+	opts = append(opts, withMounts(context))
 	cOpts = append(cOpts, containerd.WithContainerLabels(commands.LabelArgs(context.StringSlice("label"))))
+	cOpts = append(cOpts, containerd.WithRuntime(context.String("runtime"), nil))
 	if context.Bool("rootfs") {
 		opts = append(opts, oci.WithRootFSPath(ref))
 	} else {
@@ -50,19 +55,17 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 			return nil, err
 		}
 		opts = append(opts, oci.WithImageConfig(image))
-		cOpts = append(cOpts, containerd.WithImage(image))
+		cOpts = append(cOpts,
-		cOpts = append(cOpts, containerd.WithSnapshotter(context.String("snapshotter")))
+			containerd.WithImage(image),
+			containerd.WithSnapshotter(context.String("snapshotter")),
 			// Even when "readonly" is set, we don't use KindView snapshot here. (#1495)
 			// We pass writable snapshot to the OCI runtime, and the runtime remounts it as read-only,
 			// after creating some mount points on demand.
-		cOpts = append(cOpts, containerd.WithNewSnapshot(id, image))
+			containerd.WithNewSnapshot(id, image))
 	}
 	if context.Bool("readonly") {
 		opts = append(opts, oci.WithRootFSReadonly())
 	}
-	cOpts = append(cOpts, containerd.WithRuntime(context.String("runtime"), nil))
-	opts = append(opts, oci.WithEnv(context.StringSlice("env")))
-	opts = append(opts, withMounts(context))
 	if len(args) > 0 {
 		opts = append(opts, oci.WithProcessArgs(args...))
 	}
@@ -75,10 +78,20 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 	if context.Bool("net-host") {
 		opts = append(opts, oci.WithHostNamespace(specs.NetworkNamespace), oci.WithHostHostsFile, oci.WithHostResolvconf)
 	}
+	if context.IsSet("config") {
+		var s specs.Spec
+		if err := loadSpec(context.String("config"), &s); err != nil {
+			return nil, err
+		}
+		spec = containerd.WithSpec(&s, opts...)
+	} else {
+		spec = containerd.WithNewSpec(opts...)
+	}
+	cOpts = append(cOpts, spec)
+
 	// oci.WithImageConfig (WithUsername, WithUserID) depends on rootfs snapshot for resolving /etc/passwd.
 	// So cOpts needs to have precedence over opts.
 	// TODO: WithUsername, WithUserID should additionally support non-snapshot rootfs
-	cOpts = append(cOpts, []containerd.NewContainerOpts{containerd.WithNewSpec(opts...)}...)
 	return client.NewContainer(ctx, id, cOpts...)
 }
 

cmd/ctr/commands/run/run_windows.go

@@ -29,7 +29,8 @@ func withTTY(terminal bool) oci.SpecOpts {
 	return oci.WithTTY(int(size.Width), int(size.Height))
 }
 
-func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli.Context) (containerd.Container, error) {
+// NewContainer creates a new container
+func NewContainer(ctx gocontext.Context, client *containerd.Client, context *cli.Context) (containerd.Container, error) {
 	var (
 		ref  = context.Args().First()
 		id   = context.Args().Get(1)
@@ -44,25 +45,36 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 	var (
 		opts  []oci.SpecOpts
 		cOpts []containerd.NewContainerOpts
+		spec  containerd.NewContainerOpts
 	)
 	opts = append(opts, oci.WithImageConfig(image))
 	opts = append(opts, oci.WithEnv(context.StringSlice("env")))
 	opts = append(opts, withMounts(context))
+	opts = append(opts, withTTY(context.Bool("tty")))
 	if len(args) > 0 {
 		opts = append(opts, oci.WithProcessArgs(args...))
 	}
 	if cwd := context.String("cwd"); cwd != "" {
 		opts = append(opts, oci.WithProcessCwd(cwd))
 	}
-	opts = append(opts, withTTY(context.Bool("tty")))
+
+	if context.IsSet("config") {
+		var s specs.Spec
+		if err := loadSpec(context.String("config"), &s); err != nil {
+			return nil, err
+		}
+		spec = containerd.WithSpec(&s, opts...)
+	} else {
+		spec = containerd.WithNewSpec(opts...)
+	}
 
 	cOpts = append(cOpts, containerd.WithContainerLabels(commands.LabelArgs(context.StringSlice("label"))))
 	cOpts = append(cOpts, containerd.WithImage(image))
 	cOpts = append(cOpts, containerd.WithSnapshotter(context.String("snapshotter")))
 	cOpts = append(cOpts, containerd.WithNewSnapshot(id, image))
 	cOpts = append(cOpts, containerd.WithRuntime(context.String("runtime"), nil))
+	cOpts = append(cOpts, spec)
 
-	cOpts = append([]containerd.NewContainerOpts{containerd.WithNewSpec(opts...)}, cOpts...)
 	return client.NewContainer(ctx, id, cOpts...)
 }