Add pprof to runc-shim

Signed-off-by: Henry Wang <henwang@amazon.com>

cmd/containerd-shim-runc-v2/manager/manager_linux.go

@@ -23,6 +23,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -126,6 +127,59 @@ func (m manager) Name() string {
 	return m.name
 }
 
+type shimSocket struct {
+	addr string
+	s    *net.UnixListener
+	f    *os.File
+}
+
+func (s *shimSocket) Close() {
+	if s.s != nil {
+		s.s.Close()
+	}
+	if s.f != nil {
+		s.f.Close()
+	}
+	_ = shim.RemoveSocket(s.addr)
+}
+
+func newShimSocket(ctx context.Context, path, id string, debug bool) (*shimSocket, error) {
+	address, err := shim.SocketAddress(ctx, path, id, debug)
+	if err != nil {
+		return nil, err
+	}
+	socket, err := shim.NewSocket(address)
+	if err != nil {
+		// the only time where this would happen is if there is a bug and the socket
+		// was not cleaned up in the cleanup method of the shim or we are using the
+		// grouping functionality where the new process should be run with the same
+		// shim as an existing container
+		if !shim.SocketEaddrinuse(err) {
+			return nil, fmt.Errorf("create new shim socket: %w", err)
+		}
+		if !debug && shim.CanConnect(address) {
+			return &shimSocket{addr: address}, errdefs.ErrAlreadyExists
+		}
+		if err := shim.RemoveSocket(address); err != nil {
+			return nil, fmt.Errorf("remove pre-existing socket: %w", err)
+		}
+		if socket, err = shim.NewSocket(address); err != nil {
+			return nil, fmt.Errorf("try create new shim socket 2x: %w", err)
+		}
+	}
+	s := &shimSocket{
+		addr: address,
+		s:    socket,
+	}
+	f, err := socket.File()
+	if err != nil {
+		s.Close()
+		return nil, err
+	}
+	s.f = f
+	return s, nil
+}
+
 func (manager) Start(ctx context.Context, id string, opts shim.StartOpts) (_ shim.BootstrapParams, retErr error) {
 	var params shim.BootstrapParams
 	params.Version = 3
@@ -146,44 +200,35 @@ func (manager) Start(ctx context.Context, id string, opts shim.StartOpts) (_ shi
 			break
 		}
 	}
-	address, err := shim.SocketAddress(ctx, opts.Address, grouping)
-	if err != nil {
-		return params, err
-	}
 
-	socket, err := shim.NewSocket(address)
-	if err != nil {
-		// the only time where this would happen is if there is a bug and the socket
-		// was not cleaned up in the cleanup method of the shim or we are using the
-		// grouping functionality where the new process should be run with the same
-		// shim as an existing container
-		if !shim.SocketEaddrinuse(err) {
-			return params, fmt.Errorf("create new shim socket: %w", err)
-		}
-		if shim.CanConnect(address) {
-			params.Address = address
-			return params, nil
-		}
-		if err := shim.RemoveSocket(address); err != nil {
-			return params, fmt.Errorf("remove pre-existing socket: %w", err)
-		}
-		if socket, err = shim.NewSocket(address); err != nil {
-			return params, fmt.Errorf("try create new shim socket 2x: %w", err)
-		}
-	}
+	var sockets []*shimSocket
 	defer func() {
 		if retErr != nil {
-			socket.Close()
-			_ = shim.RemoveSocket(address)
+			for _, s := range sockets {
+				s.Close()
+			}
 		}
 	}()
 
-	f, err := socket.File()
+	s, err := newShimSocket(ctx, opts.Address, grouping, false)
 	if err != nil {
+		if errdefs.IsAlreadyExists(err) {
+			params.Address = s.addr
+			return params, nil
+		}
 		return params, err
 	}
+	sockets = append(sockets, s)
+	cmd.ExtraFiles = append(cmd.ExtraFiles, s.f)
 
-	cmd.ExtraFiles = append(cmd.ExtraFiles, f)
+	if opts.Debug {
+		s, err = newShimSocket(ctx, opts.Address, grouping, true)
+		if err != nil {
+			return params, err
+		}
+		sockets = append(sockets, s)
+		cmd.ExtraFiles = append(cmd.ExtraFiles, s.f)
+	}
 
 	goruntime.LockOSThread()
 	if os.Getenv("SCHED_CORE") != "" {
@@ -193,7 +238,6 @@ func (manager) Start(ctx context.Context, id string, opts shim.StartOpts) (_ shi
 	}
 
 	if err := cmd.Start(); err != nil {
-		f.Close()
 		return params, err
 	}
 
@@ -233,7 +277,7 @@ func (manager) Start(ctx context.Context, id string, opts shim.StartOpts) (_ shi
 		return params, fmt.Errorf("failed to adjust OOM score for shim: %w", err)
 	}
 
-	params.Address = address
+	params.Address = sockets[0].addr
 	return params, nil
 }