Merge pull request #9442 from AkihiroSuda/runtime-info2

api/services/instrospection: add PluginInfo

core/runtime/typeurl.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/containerd/typeurl/v2"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/opencontainers/runtime-spec/specs-go/features"
 )
 
 func init() {
@@ -31,4 +32,5 @@ func init() {
 	typeurl.Register(&specs.Process{}, prefix, "opencontainers/runtime-spec", major, "Process")
 	typeurl.Register(&specs.LinuxResources{}, prefix, "opencontainers/runtime-spec", major, "LinuxResources")
 	typeurl.Register(&specs.WindowsResources{}, prefix, "opencontainers/runtime-spec", major, "WindowsResources")
+	typeurl.Register(&features.Features{}, prefix, "opencontainers/runtime-spec", major, "features", "Features")
 }

core/runtime/v2/README.md

@@ -243,6 +243,29 @@ The delete command MUST accept the following flags:
 
 The delete command will be executed in the container's bundle as its `cwd` except for on Windows and FreeBSD platforms.
 
+### Command-like flags
+#### `-v`
+Each shim SHOULD implement a `-v` flag.
+This command-like flag prints the shim implementation version and exits.
+The output is not machine-parsable.
+
+#### `-info`
+Each shim SHOULD implement a `-info` flag.
+This command-like flag gets the option protobuf from stdin, prints the shim info protobuf (see below) to stdout, and exits.
+
+```proto
+message RuntimeInfo {
+       string name = 1;
+       RuntimeVersion version = 2;
+       // Options from stdin
+       google.protobuf.Any options = 3;
+       // OCI-compatible runtimes should use https://github.com/opencontainers/runtime-spec/blob/main/features.md
+       google.protobuf.Any features = 4;
+       // Annotations of the shim. Irrelevant to features.Annotations.
+       map<string, string> annotations = 5;
+}
+```
+
 ### Host Level Shim Configuration
 
 containerd does not provide any host level configuration for shims via the API.

core/runtime/v2/example/example.go

@@ -18,9 +18,11 @@ package example
 
 import (
 	"context"
+	"io"
 	"os"
 
 	taskAPI "github.com/containerd/containerd/v2/api/runtime/task/v2"
+	apitypes "github.com/containerd/containerd/v2/api/types"
 	"github.com/containerd/containerd/v2/core/runtime/v2/shim"
 	"github.com/containerd/containerd/v2/pkg/errdefs"
 	"github.com/containerd/containerd/v2/pkg/shutdown"
@@ -73,6 +75,16 @@ func (m manager) Stop(ctx context.Context, id string) (shim.StopStatus, error) {
 	return shim.StopStatus{}, errdefs.ErrNotImplemented
 }
 
+func (m manager) Info(ctx context.Context, optionsR io.Reader) (*apitypes.RuntimeInfo, error) {
+	info := &apitypes.RuntimeInfo{
+		Name: "io.containerd.example.v1",
+		Version: &apitypes.RuntimeVersion{
+			Version: "v1.0.0",
+		},
+	}
+	return info, nil
+}
+
 func newTaskService(ctx context.Context, publisher shim.Publisher, sd shutdown.Service) (taskAPI.TaskService, error) {
 	// The shim.Publisher and shutdown.Service are usually useful for your task service,
 	// but we don't need them in the exampleTaskService.

core/runtime/v2/manager.go

@@ -17,6 +17,7 @@
 package v2
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -26,6 +27,7 @@ import (
 	"strings"
 	"sync"
 
+	apitypes "github.com/containerd/containerd/v2/api/types"
 	"github.com/containerd/containerd/v2/core/containers"
 	"github.com/containerd/containerd/v2/core/metadata"
 	"github.com/containerd/containerd/v2/core/runtime"
@@ -38,6 +40,7 @@ import (
 	"github.com/containerd/containerd/v2/pkg/timeout"
 	"github.com/containerd/containerd/v2/plugins"
 	"github.com/containerd/containerd/v2/protobuf"
+	"github.com/containerd/containerd/v2/protobuf/proto"
 	"github.com/containerd/log"
 	"github.com/containerd/platforms"
 	"github.com/containerd/plugin"
@@ -533,3 +536,35 @@ func (m *TaskManager) Delete(ctx context.Context, taskID string) (*runtime.Exit,
 
 	return exit, nil
 }
+
+func (m *TaskManager) PluginInfo(ctx context.Context, request interface{}) (interface{}, error) {
+	req, ok := request.(*apitypes.RuntimeRequest)
+	if !ok {
+		return nil, fmt.Errorf("unknown request type %T: %w", request, errdefs.ErrNotImplemented)
+	}
+
+	runtimePath, err := m.manager.resolveRuntimePath(req.RuntimePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to resolve runtime path: %w", err)
+	}
+	var optsB []byte
+	if req.Options != nil {
+		optsB, err = proto.Marshal(req.Options)
+		if err != nil {
+			return nil, fmt.Errorf("failed to marshal %s: %w", req.Options.TypeUrl, err)
+		}
+	}
+	var stderr bytes.Buffer
+	cmd := exec.CommandContext(ctx, runtimePath, "-info")
+	cmd.Stdin = bytes.NewReader(optsB)
+	cmd.Stderr = &stderr
+	stdout, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("failed to run %v: %w (stderr: %q)", cmd.Args, err, stderr.String())
+	}
+	var info apitypes.RuntimeInfo
+	if err = proto.Unmarshal(stdout, &info); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal stdout from %v into %T: %w", cmd.Args, &info, err)
+	}
+	return &info, nil
+}

core/runtime/v2/shim/shim.go

@@ -31,6 +31,7 @@ import (
 	"time"
 
 	shimapi "github.com/containerd/containerd/v2/api/runtime/task/v3"
+	"github.com/containerd/containerd/v2/api/types"
 	"github.com/containerd/containerd/v2/pkg/events"
 	"github.com/containerd/containerd/v2/pkg/namespaces"
 	"github.com/containerd/containerd/v2/pkg/shutdown"
@@ -79,6 +80,7 @@ type Manager interface {
 	Name() string
 	Start(ctx context.Context, id string, opts StartOpts) (BootstrapParams, error)
 	Stop(ctx context.Context, id string) (StopStatus, error)
+	Info(ctx context.Context, optionsR io.Reader) (*types.RuntimeInfo, error)
 }
 
 // OptsKey is the context key for the Opts value.
@@ -116,6 +118,7 @@ type TTRPCServerOptioner interface {
 var (
 	debugFlag            bool
 	versionFlag          bool
+	infoFlag             bool
 	id                   string
 	namespaceFlag        string
 	socketFlag           string
@@ -135,6 +138,9 @@ const (
 func parseFlags() {
 	flag.BoolVar(&debugFlag, "debug", false, "enable debug output in logs")
 	flag.BoolVar(&versionFlag, "v", false, "show the shim version and exit")
+	// "info" is not a subcommand, because old shims produce very confusing errors for unknown subcommands
+	// https://github.com/containerd/containerd/pull/8509#discussion_r1210021403
+	flag.BoolVar(&infoFlag, "info", false, "get the option protobuf from stdin, print the shim info protobuf to stdout, and exit")
 	flag.StringVar(&namespaceFlag, "namespace", "", "namespace that owns the shim")
 	flag.StringVar(&id, "id", "", "id of the task")
 	flag.StringVar(&socketFlag, "socket", "", "socket path to serve")
@@ -195,6 +201,19 @@ func Run(ctx context.Context, manager Manager, opts ...BinaryOpts) {
 	}
 }
 
+func runInfo(ctx context.Context, manager Manager) error {
+	info, err := manager.Info(ctx, os.Stdin)
+	if err != nil {
+		return err
+	}
+	infoB, err := proto.Marshal(info)
+	if err != nil {
+		return err
+	}
+	_, err = os.Stdout.Write(infoB)
+	return err
+}
+
 func run(ctx context.Context, manager Manager, config Config) error {
 	parseFlags()
 	if versionFlag {
@@ -206,6 +225,10 @@ func run(ctx context.Context, manager Manager, config Config) error {
 		return nil
 	}
 
+	if infoFlag {
+		return runInfo(ctx, manager)
+	}
+
 	if namespaceFlag == "" {
 		return fmt.Errorf("shim namespace cannot be empty")
 	}