Update LCOW and WCOW paths to include pod identifiers in container root directories

For LCOWs, Prior to this change, the container root directory path was of the format-
'<Root Dir>/c/<CONTAINER_ID>'
We are changing it now to-
'<Root Dir>/pods/<SANDBOX_ID>/<CONTAINER_ID>'

For WCOWs, the only directory which is of our interest is 'C:\\SandboxMounts'. After our change, it would be of format- 'C:\\SandboxMounts\\<SANDBOX_ID>'

Signed-off-by: Harsh Rawat <harshrawat@microsoft.com>

Author: rawahars

cmd/containerd-shim-runhcs-v1/pod.go

@@ -309,7 +309,7 @@ func createPod(ctx context.Context, events publisher, req *task.CreateTaskReques
 		}
 		// LCOW (and WCOW Process Isolated for the time being) requires a real
 		// task for the sandbox.
-		lt, err := newHcsTask(ctx, events, parent, true, req, s)
+		lt, err := newHcsTask(ctx, events, parent, true, req, s, req.ID)
 		if err != nil {
 			return nil, err
 		}
@@ -408,7 +408,7 @@ func (p *pod) CreateTask(ctx context.Context, req *task.CreateTaskRequest, s *sp
 			sid)
 	}
 
-	st, err := newHcsTask(ctx, p.events, p.host, false, req, s)
+	st, err := newHcsTask(ctx, p.events, p.host, false, req, s, p.id)
 	if err != nil {
 		return nil, err
 	}

cmd/containerd-shim-runhcs-v1/task_hcs.go

@@ -105,7 +105,7 @@ func newHcsStandaloneTask(ctx context.Context, events publisher, req *task.Creat
 		return nil, errors.Wrap(errdefs.ErrFailedPrecondition, "oci spec does not contain WCOW or LCOW spec")
 	}
 
-	shim, err := newHcsTask(ctx, events, parent, true, req, s)
+	shim, err := newHcsTask(ctx, events, parent, true, req, s, req.ID)
 	if err != nil {
 		if parent != nil {
 			parent.Close()
@@ -126,6 +126,7 @@ func createContainer(
 	parent *uvm.UtilityVM,
 	shimOpts *runhcsopts.Options,
 	rootfs []*types.Mount,
+	sandboxID string,
 ) (cow.Container, *resources.Resources, error) {
 	var (
 		err       error
@@ -157,6 +158,7 @@ func createContainer(
 	} else {
 		opts := &hcsoci.CreateOptions{
 			ID:               id,
+			SandboxID:        sandboxID,
 			Owner:            owner,
 			Spec:             s,
 			HostingSystem:    parent,
@@ -186,7 +188,9 @@ func newHcsTask(
 	parent *uvm.UtilityVM,
 	ownsParent bool,
 	req *task.CreateTaskRequest,
-	s *specs.Spec) (_ shimTask, err error) {
+	s *specs.Spec,
+	sandboxID string,
+) (_ shimTask, err error) {
 	log.G(ctx).WithFields(logrus.Fields{
 		"tid":        req.ID,
 		"ownsParent": ownsParent,
@@ -219,7 +223,7 @@ func newHcsTask(
 		return nil, err
 	}
 
-	container, resources, err := createContainer(ctx, req.ID, owner, netNS, s, parent, shimOpts, req.Rootfs)
+	container, resources, err := createContainer(ctx, req.ID, owner, netNS, s, parent, shimOpts, req.Rootfs, sandboxID)
 	if err != nil {
 		return nil, err
 	}

internal/guestpath/paths.go

@@ -3,7 +3,7 @@ package guestpath
 const (
 	// LCOWRootPrefixInUVM is the path inside UVM where LCOW container's root
 	// file system will be mounted
-	LCOWRootPrefixInUVM = "/run/gcs/c"
+	LCOWRootPrefixInUVM = "/run/gcs/pods"
 	// WCOWRootPrefixInUVM is the path inside UVM where WCOW container's root
 	// file system will be mounted
 	WCOWRootPrefixInUVM = `C:\c`

internal/hcsoci/create.go

@@ -31,7 +31,7 @@ import (
 )
 
 var (
-	lcowRootInUVM = guestpath.LCOWRootPrefixInUVM + "/%s"
+	lcowRootInUVM = guestpath.LCOWRootPrefixInUVM + "/%s/%s"
 	wcowRootInUVM = guestpath.WCOWRootPrefixInUVM + "/%s"
 )
 
@@ -43,6 +43,7 @@ var (
 type CreateOptions struct {
 	// Common parameters
 	ID               string             // Identifier for the container
+	SandboxID        string             // Identifier for the pod of this container.
 	Owner            string             // Specifies the owner. Defaults to executable name.
 	Spec             *specs.Spec        // Definition of the container or utility VM being created
 	SchemaVersion    *hcsschema.Version // Requested Schema Version. Defaults to v2 for RS5, v1 for RS1..RS4
@@ -205,7 +206,9 @@ func CreateContainer(ctx context.Context, createOptions *CreateOptions) (_ cow.C
 
 	if coi.HostingSystem != nil {
 		if coi.Spec.Linux != nil {
-			r.SetContainerRootInUVM(fmt.Sprintf(lcowRootInUVM, coi.ID))
+			// The container root within the UVM would be as below-
+			// <Root Dir>/pods/<PodID>/<ContainerID>
+			r.SetContainerRootInUVM(fmt.Sprintf(lcowRootInUVM, coi.SandboxID, coi.ID))
 		} else {
 			n := coi.HostingSystem.ContainerCounter()
 			r.SetContainerRootInUVM(fmt.Sprintf(wcowRootInUVM, strconv.FormatUint(n, 16)))

internal/hcsoci/hcsdoc_wcow.go

@@ -73,7 +73,7 @@ func createMountsConfig(ctx context.Context, coi *createOptionsInternal) (*mount
 			continue
 		} else if strings.HasPrefix(mount.Source, guestpath.SandboxMountPrefix) {
 			// Convert to the path in the guest that was asked for.
-			mdv2.HostPath = convertToWCOWSandboxMountPath(mount.Source)
+			mdv2.HostPath = convertToWCOWSandboxMountPath(coi.SandboxID, mount.Source)
 		} else {
 			// vsmb mount
 			uvmPath, err := coi.HostingSystem.GetVSMBUvmPath(ctx, mount.Source, readOnly)

internal/hcsoci/resources_wcow.go

@@ -27,7 +27,7 @@ import (
 	"github.com/Microsoft/hcsshim/internal/uvm/scsi"
 )
 
-const wcowSandboxMountPath = "C:\\SandboxMounts"
+const wcowSandboxMountPath = "C:\\SandboxMounts\\%s"
 
 func allocateWindowsResources(ctx context.Context, coi *createOptionsInternal, r *resources.Resources, isSandbox bool) error {
 	if coi.Spec.Root == nil {
@@ -193,7 +193,7 @@ func setupMounts(ctx context.Context, coi *createOptionsInternal, r *resources.R
 			//   - sandbox:///a/dirInUvm destination:C:\\dirInContainer.
 			//
 			// so first convert to a path in the sandboxmounts path itself.
-			sandboxPath := convertToWCOWSandboxMountPath(mount.Source)
+			sandboxPath := convertToWCOWSandboxMountPath(coi.SandboxID, mount.Source)
 
 			// Now we need to exec a process in the vm that will make these directories as theres
 			// no functionality in the Windows gcs to create an arbitrary directory.
@@ -238,7 +238,8 @@ func setupMounts(ctx context.Context, coi *createOptionsInternal, r *resources.R
 	return nil
 }
 
-func convertToWCOWSandboxMountPath(source string) string {
+func convertToWCOWSandboxMountPath(sandboxID string, source string) string {
 	subPath := strings.TrimPrefix(source, guestpath.SandboxMountPrefix)
-	return filepath.Join(wcowSandboxMountPath, subPath)
+	wcowSandboxMountPathPrefix := fmt.Sprintf(wcowSandboxMountPath, sandboxID)
+	return filepath.Join(wcowSandboxMountPathPrefix, subPath)
 }