containerd/vendor/github.com/Microsoft/hcsshim/internal/wclayer/cim/process.go
Kirtana Ashok d9409c4611 Update hcsshim to v0.12.0
Signed-off-by: Kirtana Ashok <kiashok@microsoft.com>
2024-03-04 16:55:07 -08:00

231 lines
9.0 KiB
Go

//go:build windows
package cim
import (
"context"
"fmt"
"os"
"path/filepath"
"syscall"
"time"
"github.com/Microsoft/go-winio"
"github.com/Microsoft/go-winio/vhd"
"github.com/Microsoft/hcsshim/computestorage"
"github.com/Microsoft/hcsshim/internal/memory"
"github.com/Microsoft/hcsshim/internal/security"
"github.com/Microsoft/hcsshim/internal/vhdx"
"github.com/Microsoft/hcsshim/internal/wclayer"
"golang.org/x/sys/windows"
)
const defaultVHDXBlockSizeInMB = 1
// processUtilityVMLayer is similar to createContainerBaseLayerVHDs but along with the scratch creation it
// also does some BCD modifications to allow the UVM to boot from the CIM. It expects that the UVM BCD file is
// present at layerPath/`wclayer.BcdFilePath` and a UVM SYSTEM hive is present at
// layerPath/UtilityVM/`wclayer.RegFilesPath`/SYSTEM. The scratch VHDs are created under the `layerPath`
// directory.
func processUtilityVMLayer(ctx context.Context, layerPath string) error {
// func createUtilityVMLayerVHDs(ctx context.Context, layerPath string) error {
baseVhdPath := filepath.Join(layerPath, wclayer.UtilityVMPath, wclayer.UtilityVMBaseVhd)
diffVhdPath := filepath.Join(layerPath, wclayer.UtilityVMPath, wclayer.UtilityVMScratchVhd)
defaultVhdSize := uint64(10)
// Just create the vhdx for utilityVM layer, no need to format it.
createParams := &vhd.CreateVirtualDiskParameters{
Version: 2,
Version2: vhd.CreateVersion2{
MaximumSize: defaultVhdSize * memory.GiB,
BlockSizeInBytes: defaultVHDXBlockSizeInMB * memory.MiB,
},
}
handle, err := vhd.CreateVirtualDisk(baseVhdPath, vhd.VirtualDiskAccessNone, vhd.CreateVirtualDiskFlagNone, createParams)
if err != nil {
return fmt.Errorf("failed to create vhdx: %w", err)
}
defer func() {
if err != nil {
os.RemoveAll(baseVhdPath)
os.RemoveAll(diffVhdPath)
}
}()
err = computestorage.FormatWritableLayerVhd(ctx, windows.Handle(handle))
closeErr := syscall.CloseHandle(handle)
if err != nil {
return err
} else if closeErr != nil {
return fmt.Errorf("failed to close vhdx handle: %w", closeErr)
}
partitionInfo, err := vhdx.GetScratchVhdPartitionInfo(ctx, baseVhdPath)
if err != nil {
return fmt.Errorf("failed to get base vhd layout info: %w", err)
}
// relativeCimPath needs to be the cim path relative to the snapshots directory. The snapshots
// directory is shared inside the UVM over VSMB, so during the UVM boot this relative path will be
// used to find the cim file under that VSMB share.
relativeCimPath := filepath.Join(filepath.Base(GetCimDirFromLayer(layerPath)), GetCimNameFromLayer(layerPath))
bcdPath := filepath.Join(layerPath, bcdFilePath)
if err = updateBcdStoreForBoot(bcdPath, relativeCimPath, partitionInfo.DiskID, partitionInfo.PartitionID); err != nil {
return fmt.Errorf("failed to update BCD: %w", err)
}
if err := enableCimBoot(filepath.Join(layerPath, wclayer.UtilityVMPath, wclayer.RegFilesPath, "SYSTEM")); err != nil {
return fmt.Errorf("failed to setup cim image for uvm boot: %w", err)
}
// Note: diff vhd creation and granting of vm group access must be done AFTER
// getting the partition info of the base VHD. Otherwise it causes the vhd parent
// chain to get corrupted.
// TODO(ambarve): figure out why this happens so that bcd update can be moved to a separate function
// Create the differencing disk that will be what's copied for the final rw layer
// for a container.
if err = vhd.CreateDiffVhd(diffVhdPath, baseVhdPath, defaultVHDXBlockSizeInMB); err != nil {
return fmt.Errorf("failed to create differencing disk: %w", err)
}
if err := security.GrantVmGroupAccess(baseVhdPath); err != nil {
return fmt.Errorf("failed to grant vm group access to %s: %w", baseVhdPath, err)
}
if err := security.GrantVmGroupAccess(diffVhdPath); err != nil {
return fmt.Errorf("failed to grant vm group access to %s: %w", diffVhdPath, err)
}
return nil
}
// processBaseLayerHives make the base layer specific modifications on the hives and emits equivalent the
// pendingCimOps that should be applied on the CIM. In base layer we need to create hard links from registry
// hives under Files/Windows/Sysetm32/config into Hives/*_BASE. This function creates these links outside so
// that the registry hives under Hives/ are available during children layers import. Then we write these hive
// files inside the cim and create links inside the cim.
func processBaseLayerHives(layerPath string) ([]pendingCimOp, error) {
pendingOps := []pendingCimOp{}
// make hives directory both outside and in the cim
if err := os.Mkdir(filepath.Join(layerPath, wclayer.HivesPath), 0755); err != nil {
return pendingOps, fmt.Errorf("hives directory creation: %w", err)
}
hivesDirInfo := &winio.FileBasicInfo{
CreationTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastAccessTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastWriteTime: windows.NsecToFiletime(time.Now().UnixNano()),
ChangeTime: windows.NsecToFiletime(time.Now().UnixNano()),
FileAttributes: windows.FILE_ATTRIBUTE_DIRECTORY,
}
pendingOps = append(pendingOps, &addOp{
pathInCim: wclayer.HivesPath,
hostPath: filepath.Join(layerPath, wclayer.HivesPath),
fileInfo: hivesDirInfo,
})
// add hard links from base hive files.
for _, hv := range hives {
oldHivePathRelative := filepath.Join(wclayer.RegFilesPath, hv.name)
newHivePathRelative := filepath.Join(wclayer.HivesPath, hv.base)
if err := os.Link(filepath.Join(layerPath, oldHivePathRelative), filepath.Join(layerPath, newHivePathRelative)); err != nil {
return pendingOps, fmt.Errorf("hive link creation: %w", err)
}
pendingOps = append(pendingOps, &linkOp{
oldPath: oldHivePathRelative,
newPath: newHivePathRelative,
})
}
return pendingOps, nil
}
// processLayoutFile creates a file named "layout" in the root of the base layer. This allows certain
// container startup related functions to understand that the hives are a part of the container rootfs.
func processLayoutFile(layerPath string) ([]pendingCimOp, error) {
fileContents := "vhd-with-hives\n"
if err := os.WriteFile(filepath.Join(layerPath, "layout"), []byte(fileContents), 0755); err != nil {
return []pendingCimOp{}, fmt.Errorf("write layout file: %w", err)
}
layoutFileInfo := &winio.FileBasicInfo{
CreationTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastAccessTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastWriteTime: windows.NsecToFiletime(time.Now().UnixNano()),
ChangeTime: windows.NsecToFiletime(time.Now().UnixNano()),
FileAttributes: windows.FILE_ATTRIBUTE_NORMAL,
}
op := &addOp{
pathInCim: "layout",
hostPath: filepath.Join(layerPath, "layout"),
fileInfo: layoutFileInfo,
}
return []pendingCimOp{op}, nil
}
// Some of the layer files that are generated during the processBaseLayer call must be added back
// inside the cim, some registry file links must be updated. This function takes care of all those
// steps. This function opens the cim file for writing and updates it.
func (cw *CimLayerWriter) processBaseLayer(ctx context.Context, processUtilityVM bool) (err error) {
if processUtilityVM {
if err = processUtilityVMLayer(ctx, cw.path); err != nil {
return fmt.Errorf("process utilityVM layer: %w", err)
}
}
ops, err := processBaseLayerHives(cw.path)
if err != nil {
return err
}
cw.pendingOps = append(cw.pendingOps, ops...)
ops, err = processLayoutFile(cw.path)
if err != nil {
return err
}
cw.pendingOps = append(cw.pendingOps, ops...)
return nil
}
// processNonBaseLayer takes care of the processing required for a non base layer. As of now
// the only processing required for non base layer is to merge the delta registry hives of the
// non-base layer with it's parent layer.
func (cw *CimLayerWriter) processNonBaseLayer(ctx context.Context, processUtilityVM bool) (err error) {
for _, hv := range hives {
baseHive := filepath.Join(wclayer.HivesPath, hv.base)
deltaHive := filepath.Join(wclayer.HivesPath, hv.delta)
_, err := os.Stat(filepath.Join(cw.path, deltaHive))
// merge with parent layer if delta exists.
if err != nil && !os.IsNotExist(err) {
return fmt.Errorf("stat delta hive %s: %w", filepath.Join(cw.path, deltaHive), err)
} else if err == nil {
// merge base hive of parent layer with the delta hive of this layer and write it as
// the base hive of this layer.
err = mergeHive(filepath.Join(cw.parentLayerPaths[0], baseHive), filepath.Join(cw.path, deltaHive), filepath.Join(cw.path, baseHive))
if err != nil {
return err
}
// the newly created merged file must be added to the cim
cw.pendingOps = append(cw.pendingOps, &addOp{
pathInCim: baseHive,
hostPath: filepath.Join(cw.path, baseHive),
fileInfo: &winio.FileBasicInfo{
CreationTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastAccessTime: windows.NsecToFiletime(time.Now().UnixNano()),
LastWriteTime: windows.NsecToFiletime(time.Now().UnixNano()),
ChangeTime: windows.NsecToFiletime(time.Now().UnixNano()),
FileAttributes: windows.FILE_ATTRIBUTE_NORMAL,
},
})
}
}
if processUtilityVM {
return processUtilityVMLayer(ctx, cw.path)
}
return nil
}