Implements Windows volume/mount support

Based on WSL2 9p support: remaps windows paths to /mnt/<drive> locations for
both podman and Docker API clients.

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

11 files changed, 273 insertions, 13 deletions

diff --git a/cmd/podman/common/create_opts.go b/cmd/podman/common/create_opts.go
index 7b7626040..16f193b03 100644
--- a/cmd/podman/common/create_opts.go
+++ b/cmd/podman/common/create_opts.go
@@ -347,7 +347,7 @@ func ContainerCreateToContainerCLIOpts(cc handlers.CreateContainerConfig, rtc *c
 		cliOpts.Volume = append(cliOpts.Volume, vol)
 		// Extract the destination so we don't add duplicate mounts in
 		// the volumes phase.
-		splitVol := strings.SplitN(vol, ":", 3)
+		splitVol := specgen.SplitVolumeString(vol)
 		switch len(splitVol) {
 		case 1:
 			volDestinations[vol] = true
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index c168b7eca..a312f5a0c 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -63,7 +63,7 @@ const (
 // This is need because a HostIP of 127.0.0.1 would now allow the gvproxy forwarder to reach to open ports.
 // For machine the HostIP must only be used by gvproxy and never in the VM.
 func (c *Container) convertPortMappings() []types.PortMapping {
-	if !machine.IsPodmanMachine() || len(c.config.PortMappings) == 0 {
+	if !machine.IsGvProxyBased() || len(c.config.PortMappings) == 0 {
 		return c.config.PortMappings
 	}
 	// if we run in a machine VM we have to ignore the host IP part
diff --git a/pkg/machine/ignition.go b/pkg/machine/ignition.go
index fe47437e3..35a9a30cb 100644
--- a/pkg/machine/ignition.go
+++ b/pkg/machine/ignition.go
@@ -304,6 +304,8 @@ ExecStart=/usr/bin/sleep infinity
 	containers := `[containers]
 netns="bridge"
 `
+	// Set deprecated machine_enabled until podman package on fcos is
+	// current enough to no longer require it
 	rootContainers := `[engine]
 machine_enabled=true
 `
@@ -392,7 +394,7 @@ Delegate=memory pids cpu io
 		FileEmbedded1: FileEmbedded1{Mode: intToPtr(0644)},
 	})
 
-	// Set machine_enabled to true to indicate we're in a VM
+	// Set deprecated machine_enabled to true to indicate we're in a VM
 	files = append(files, File{
 		Node: Node{
 			Group: getNodeGrp("root"),
@@ -408,6 +410,22 @@ Delegate=memory pids cpu io
 		},
 	})
 
+	// Set machine marker file to indicate podman is in a qemu based machine
+	files = append(files, File{
+		Node: Node{
+			Group: getNodeGrp("root"),
+			Path:  "/etc/containers/podman-machine",
+			User:  getNodeUsr("root"),
+		},
+		FileEmbedded1: FileEmbedded1{
+			Append: nil,
+			Contents: Resource{
+				Source: encodeDataURLPtr("qemu\n"),
+			},
+			Mode: intToPtr(0644),
+		},
+	})
+
 	// Issue #11489: make sure that we can inject a custom registries.conf
 	// file on the system level to force a single search registry.
 	// The remote client does not yet support prompting for short-name
diff --git a/pkg/machine/wsl/machine.go b/pkg/machine/wsl/machine.go
index dff7bfef9..38bd4e96d 100644
--- a/pkg/machine/wsl/machine.go
+++ b/pkg/machine/wsl/machine.go
@@ -448,6 +448,10 @@ func configureSystem(v *MachineVM, dist string) error {
 		return errors.Wrap(err, "could not create containers.conf for guest OS")
 	}
 
+	if err := runCmdPassThrough("wsl", "-d", dist, "sh", "-c", "echo wsl > /etc/containers/podman-machine"); err != nil {
+		return errors.Wrap(err, "could not create podman-machine file for guest OS")
+	}
+
 	return nil
 }
 
diff --git a/pkg/specgen/volumes.go b/pkg/specgen/volumes.go
index eca8c0c35..b26666df3 100644
--- a/pkg/specgen/volumes.go
+++ b/pkg/specgen/volumes.go
@@ -65,7 +65,7 @@ func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*Na
 			err     error
 		)
 
-		splitVol := strings.Split(vol, ":")
+		splitVol := SplitVolumeString(vol)
 		if len(splitVol) > 3 {
 			return nil, nil, nil, errors.Wrapf(volumeFormatErr, vol)
 		}
@@ -93,7 +93,7 @@ func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*Na
 			}
 		}
 
-		if strings.HasPrefix(src, "/") || strings.HasPrefix(src, ".") {
+		if strings.HasPrefix(src, "/") || strings.HasPrefix(src, ".") || isHostWinPath(src) {
 			// This is not a named volume
 			overlayFlag := false
 			chownFlag := false
@@ -152,3 +152,26 @@ func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*Na
 
 	return mounts, volumes, overlayVolumes, nil
 }
+
+// Splits a volume string, accounting for Win drive paths
+// when running as a WSL linux guest or Windows client
+func SplitVolumeString(vol string) []string {
+	parts := strings.Split(vol, ":")
+	if !shouldResolveWinPaths() {
+		return parts
+	}
+
+	// Skip extended marker prefix if present
+	n := 0
+	if strings.HasPrefix(vol, `\\?\`) {
+		n = 4
+	}
+
+	if hasWinDriveScheme(vol, n) {
+		first := parts[0] + ":" + parts[1]
+		parts = parts[1:]
+		parts[0] = first
+	}
+
+	return parts
+}
diff --git a/pkg/specgen/winpath.go b/pkg/specgen/winpath.go
new file mode 100644
index 000000000..f4249fab1
--- /dev/null
+++ b/pkg/specgen/winpath.go
@@ -0,0 +1,59 @@
+package specgen
+
+import (
+	"fmt"
+	"strings"
+	"unicode"
+
+	"github.com/pkg/errors"
+)
+
+func isHostWinPath(path string) bool {
+	return shouldResolveWinPaths() && strings.HasPrefix(path, `\\`) || hasWinDriveScheme(path, 0) || winPathExists(path)
+}
+
+func hasWinDriveScheme(path string, start int) bool {
+	if len(path) < start+2 || path[start+1] != ':' {
+		return false
+	}
+
+	drive := rune(path[start])
+	return drive < unicode.MaxASCII && unicode.IsLetter(drive)
+}
+
+// Converts a Windows path to a WSL guest path if local env is a WSL linux guest or this is a Windows client.
+func ConvertWinMountPath(path string) (string, error) {
+	if !shouldResolveWinPaths() {
+		return path, nil
+	}
+
+	if strings.HasPrefix(path, "/") {
+		// Handle /[driveletter]/windows/path form (e.g. c:\Users\bar == /c/Users/bar)
+		if len(path) > 2 && path[2] == '/' && shouldResolveUnixWinVariant(path) {
+			drive := unicode.ToLower(rune(path[1]))
+			if unicode.IsLetter(drive) && drive <= unicode.MaxASCII {
+				return fmt.Sprintf("/mnt/%c/%s", drive, path[3:]), nil
+			}
+		}
+
+		// unix path - pass through
+		return path, nil
+	}
+
+	// Convert remote win client relative paths to absolute
+	path = resolveRelativeOnWindows(path)
+
+	// Strip extended marker prefix if present
+	path = strings.TrimPrefix(path, `\\?\`)
+
+	// Drive installed via wsl --mount
+	if strings.HasPrefix(path, `\\.\`) {
+		path = "/mnt/wsl/" + path[4:]
+	} else if len(path) > 1 && path[1] == ':' {
+		path = "/mnt/" + strings.ToLower(path[0:1]) + path[2:]
+	} else {
+		return path, errors.New("unsupported UNC path")
+	}
+
+	return strings.ReplaceAll(path, `\`, "/"), nil
+}
diff --git a/pkg/specgen/winpath_linux.go b/pkg/specgen/winpath_linux.go
new file mode 100644
index 000000000..f42ac7639
--- /dev/null
+++ b/pkg/specgen/winpath_linux.go
@@ -0,0 +1,24 @@
+package specgen
+
+import (
+	"os"
+
+	"github.com/containers/common/pkg/machine"
+)
+
+func shouldResolveWinPaths() bool {
+	return machine.MachineHostType() == "wsl"
+}
+
+func shouldResolveUnixWinVariant(path string) bool {
+	_, err := os.Stat(path)
+	return err != nil
+}
+
+func resolveRelativeOnWindows(path string) string {
+	return path
+}
+
+func winPathExists(path string) bool {
+	return false
+}
diff --git a/pkg/specgen/winpath_unsupported.go b/pkg/specgen/winpath_unsupported.go
new file mode 100644
index 000000000..4cd008fdd
--- /dev/null
+++ b/pkg/specgen/winpath_unsupported.go
@@ -0,0 +1,20 @@
+//go:build !linux && !windows
+// +build !linux,!windows
+
+package specgen
+
+func shouldResolveWinPaths() bool {
+	return false
+}
+
+func shouldResolveUnixWinVariant(path string) bool {
+	return false
+}
+
+func resolveRelativeOnWindows(path string) string {
+	return path
+}
+
+func winPathExists(path string) bool {
+	return false
+}
diff --git a/pkg/specgen/winpath_windows.go b/pkg/specgen/winpath_windows.go
new file mode 100644
index 000000000..c6aad314a
--- /dev/null
+++ b/pkg/specgen/winpath_windows.go
@@ -0,0 +1,30 @@
+package specgen
+
+import (
+	"github.com/sirupsen/logrus"
+	"os"
+	"path/filepath"
+)
+
+func shouldResolveUnixWinVariant(path string) bool {
+	return true
+}
+
+func shouldResolveWinPaths() bool {
+	return true
+}
+
+func resolveRelativeOnWindows(path string) string {
+	ret, err := filepath.Abs(path)
+	if err != nil {
+		logrus.Debugf("problem resolving possible relative path %q: %s", path, err.Error())
+		return path
+	}
+
+	return ret
+}
+
+func winPathExists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil
+}
diff --git a/pkg/specgenutil/specgenutil_test.go b/pkg/specgenutil/specgenutil_test.go
new file mode 100644
index 000000000..5867b0ae0
--- /dev/null
+++ b/pkg/specgenutil/specgenutil_test.go
@@ -0,0 +1,77 @@
+//go:build linux
+// +build linux
+
+package specgenutil
+
+import (
+	"testing"
+
+	"github.com/containers/common/pkg/machine"
+	"github.com/containers/podman/v4/pkg/domain/entities"
+	"github.com/containers/podman/v4/pkg/specgen"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWinPath(t *testing.T) {
+	const (
+		fail = false
+		pass = true
+	)
+	tests := []struct {
+		vol     string
+		source  string
+		dest    string
+		isN     bool
+		outcome bool
+		mach    string
+	}{
+		{`C:\Foo:/blah`, "/mnt/c/Foo", "/blah", false, pass, "wsl"},
+		{`C:\Foo:/blah`, "/mnt/c/Foo", "/blah", false, fail, ""},
+		{`\\?\C:\Foo:/blah`, "/mnt/c/Foo", "/blah", false, pass, "wsl"},
+		{`/c/bar:/blah`, "/mnt/c/bar", "/blah", false, pass, "wsl"},
+		{`/c/bar:/blah`, "/c/bar", "/blah", false, pass, ""},
+		{`/test/this:/blah`, "/test/this", "/blah", false, pass, "wsl"},
+		{`c:/bar/something:/other`, "/mnt/c/bar/something", "/other", false, pass, "wsl"},
+		{`c:/foo:ro`, "c", "/foo", true, pass, ""},
+		{`\\computer\loc:/dest`, "", "", false, fail, "wsl"},
+		{`\\.\drive\loc:/target`, "/mnt/wsl/drive/loc", "/target", false, pass, "wsl"},
+	}
+
+	f := func(vol string, mach string) (*specgen.SpecGenerator, error) {
+		machine := machine.GetMachineMarker()
+		oldEnable, oldType := machine.Enabled, machine.Type
+		machine.Enabled, machine.Type = len(mach) > 0, mach
+		sg := specgen.NewSpecGenerator("nothing", false)
+		err := FillOutSpecGen(sg, &entities.ContainerCreateOptions{
+			ImageVolume: "ignore",
+			Volume:      []string{vol}}, []string{},
+		)
+		machine.Enabled, machine.Type = oldEnable, oldType
+		return sg, err
+	}
+
+	for _, test := range tests {
+		msg := "Checking: " + test.vol
+		sg, err := f(test.vol, test.mach)
+		if test.outcome == fail {
+			assert.NotNil(t, err, msg)
+			continue
+		}
+		if !assert.Nil(t, err, msg) {
+			continue
+		}
+		if test.isN {
+			if !assert.Equal(t, 1, len(sg.Volumes), msg) {
+				continue
+			}
+			assert.Equal(t, test.source, sg.Volumes[0].Name, msg)
+			assert.Equal(t, test.dest, sg.Volumes[0].Dest, msg)
+		} else {
+			if !assert.Equal(t, 1, len(sg.Mounts), msg) {
+				continue
+			}
+			assert.Equal(t, test.source, sg.Mounts[0].Source, msg)
+			assert.Equal(t, test.dest, sg.Mounts[0].Destination, msg)
+		}
+	}
+}
diff --git a/pkg/specgenutil/volumes.go b/pkg/specgenutil/volumes.go
index 95ce420f8..50d745380 100644
--- a/pkg/specgenutil/volumes.go
+++ b/pkg/specgenutil/volumes.go
@@ -3,7 +3,7 @@ package specgenutil
 import (
 	"encoding/csv"
 	"fmt"
-	"path/filepath"
+	"path"
 	"strings"
 
 	"github.com/containers/common/pkg/parse"
@@ -123,7 +123,7 @@ func parseVolumes(volumeFlag, mountFlag, tmpfsFlag []string, addReadOnlyTmpfs bo
 	finalMounts := make([]spec.Mount, 0, len(unifiedMounts))
 	for _, mount := range unifiedMounts {
 		if mount.Type == define.TypeBind {
-			absSrc, err := filepath.Abs(mount.Source)
+			absSrc, err := specgen.ConvertWinMountPath(mount.Source)
 			if err != nil {
 				return nil, nil, nil, nil, errors.Wrapf(err, "error getting absolute path of %s", mount.Source)
 			}
@@ -334,7 +334,7 @@ func getBindMount(args []string) (spec.Mount, error) {
 			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
 				return newMount, err
 			}
-			newMount.Destination = filepath.Clean(kv[1])
+			newMount.Destination = unixPathClean(kv[1])
 			setDest = true
 		case "relabel":
 			if setRelabel {
@@ -456,7 +456,7 @@ func getTmpfsMount(args []string) (spec.Mount, error) {
 			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
 				return newMount, err
 			}
-			newMount.Destination = filepath.Clean(kv[1])
+			newMount.Destination = unixPathClean(kv[1])
 			setDest = true
 		case "U", "chown":
 			if setOwnership {
@@ -507,7 +507,7 @@ func getDevptsMount(args []string) (spec.Mount, error) {
 			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
 				return newMount, err
 			}
-			newMount.Destination = filepath.Clean(kv[1])
+			newMount.Destination = unixPathClean(kv[1])
 			setDest = true
 		default:
 			return newMount, errors.Wrapf(util.ErrBadMntOption, "%s", kv[0])
@@ -572,7 +572,7 @@ func getNamedVolume(args []string) (*specgen.NamedVolume, error) {
 			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
 				return nil, err
 			}
-			newVolume.Dest = filepath.Clean(kv[1])
+			newVolume.Dest = unixPathClean(kv[1])
 			setDest = true
 		case "U", "chown":
 			if setOwnership {
@@ -624,7 +624,7 @@ func getImageVolume(args []string) (*specgen.ImageVolume, error) {
 			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
 				return nil, err
 			}
-			newVolume.Destination = filepath.Clean(kv[1])
+			newVolume.Destination = unixPathClean(kv[1])
 		case "rw", "readwrite":
 			switch kv[1] {
 			case "true":
@@ -670,7 +670,7 @@ func getTmpfsMounts(tmpfsFlag []string) (map[string]spec.Mount, error) {
 		}
 
 		mount := spec.Mount{
-			Destination: filepath.Clean(destPath),
+			Destination: unixPathClean(destPath),
 			Type:        define.TypeTmpfs,
 			Options:     options,
 			Source:      define.TypeTmpfs,
@@ -700,3 +700,8 @@ func validChownFlag(flag string) (bool, error) {
 
 	return true, nil
 }
+
+// Use path instead of filepath to preserve Unix style paths on Windows
+func unixPathClean(p string) string {
+	return path.Clean(p)
+}