Enable basic volumes support in Podmanv2

This enables the --volume, --mount, and --tmpfs flags in
Podmanv2. It does not enable init-related flags, image volumes,
and --volumes-from.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

2 files changed, 587 insertions, 9 deletions

diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go
index 1e857ea01..10ae0bb2d 100644
--- a/cmd/podman/common/specgen.go
+++ b/cmd/podman/common/specgen.go
@@ -548,22 +548,31 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string
 	}
 
 	s.SeccompPolicy = c.SeccompPolicy
+
+	// TODO: should parse out options
+	s.VolumesFrom = c.VolumesFrom
+
+	// Only add read-only tmpfs mounts in case that we are read-only and the
+	// read-only tmpfs flag has been set.
+	mounts, volumes, err := parseVolumes(c.Volume, c.Mount, c.TmpFS, (c.ReadOnlyTmpFS && c.ReadOnly))
+	if err != nil {
+		return err
+	}
+	s.Mounts = mounts
+	s.Volumes = volumes
+
 	// TODO any idea why this was done
-	// storage.go from spec/
-	// grab it
-	//volumes := rtc.Containers.Volumes
+	//devices := rtc.Containers.Devices
 	// TODO conflict on populate?
-	//if v := c.Volume; len(v)> 0 {
-	//	s.Volumes = append(volumes, c.StringSlice("volume")...)
+	//
+	//if c.Changed("device") {
+	//	devices = append(devices, c.StringSlice("device")...)
 	//}
-	//s.volu
-
-	//s.Mounts = c.Mount
-	s.VolumesFrom = c.VolumesFrom
 
 	for _, dev := range c.Devices {
 		s.Devices = append(s.Devices, specs.LinuxDevice{Path: dev})
 	}
+
 	// TODO things i cannot find in spec
 	// we dont think these are in the spec
 	// init - initbinary
diff --git a/cmd/podman/common/volumes.go b/cmd/podman/common/volumes.go
new file mode 100644
index 000000000..6b0b6e9cf
--- /dev/null
+++ b/cmd/podman/common/volumes.go
@@ -0,0 +1,569 @@
+package common
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/buildah/pkg/parse"
+	"github.com/containers/libpod/pkg/specgen"
+	"github.com/containers/libpod/pkg/util"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// TypeBind is the type for mounting host dir
+	TypeBind = "bind"
+	// TypeVolume is the type for named volumes
+	TypeVolume = "volume"
+	// TypeTmpfs is the type for mounting tmpfs
+	TypeTmpfs = "tmpfs"
+)
+
+var (
+	errDuplicateDest = errors.Errorf("duplicate mount destination")
+	optionArgError   = errors.Errorf("must provide an argument for option")
+	noDestError      = errors.Errorf("must set volume destination")
+)
+
+// Parse all volume-related options in the create config into a set of mounts
+// and named volumes to add to the container.
+// Handles --volumes, --mount, and --tmpfs flags.
+// Does not handle image volumes, init, and --volumes-from flags.
+// Can also add tmpfs mounts from read-only tmpfs.
+// TODO: handle options parsing/processing via containers/storage/pkg/mount
+func parseVolumes(volumeFlag, mountFlag, tmpfsFlag []string, addReadOnlyTmpfs bool) ([]spec.Mount, []*specgen.NamedVolume, error) {
+	// Get mounts from the --mounts flag.
+	unifiedMounts, unifiedVolumes, err := getMounts(mountFlag)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Next --volumes flag.
+	volumeMounts, volumeVolumes, err := getVolumeMounts(volumeFlag)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Next --tmpfs flag.
+	tmpfsMounts, err := getTmpfsMounts(tmpfsFlag)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Unify mounts from --mount, --volume, --tmpfs.
+	// Start with --volume.
+	for dest, mount := range volumeMounts {
+		if _, ok := unifiedMounts[dest]; ok {
+			return nil, nil, errors.Wrapf(errDuplicateDest, dest)
+		}
+		unifiedMounts[dest] = mount
+	}
+	for dest, volume := range volumeVolumes {
+		if _, ok := unifiedVolumes[dest]; ok {
+			return nil, nil, errors.Wrapf(errDuplicateDest, dest)
+		}
+		unifiedVolumes[dest] = volume
+	}
+	// Now --tmpfs
+	for dest, tmpfs := range tmpfsMounts {
+		if _, ok := unifiedMounts[dest]; ok {
+			return nil, nil, errors.Wrapf(errDuplicateDest, dest)
+		}
+		unifiedMounts[dest] = tmpfs
+	}
+
+	// If requested, add tmpfs filesystems for read-only containers.
+	if addReadOnlyTmpfs {
+		readonlyTmpfs := []string{"/tmp", "/var/tmp", "/run"}
+		options := []string{"rw", "rprivate", "nosuid", "nodev", "tmpcopyup"}
+		for _, dest := range readonlyTmpfs {
+			if _, ok := unifiedMounts[dest]; ok {
+				continue
+			}
+			if _, ok := unifiedVolumes[dest]; ok {
+				continue
+			}
+			localOpts := options
+			if dest == "/run" {
+				localOpts = append(localOpts, "noexec", "size=65536k")
+			} else {
+				localOpts = append(localOpts, "exec")
+			}
+			unifiedMounts[dest] = spec.Mount{
+				Destination: dest,
+				Type:        TypeTmpfs,
+				Source:      "tmpfs",
+				Options:     localOpts,
+			}
+		}
+	}
+
+	// Check for conflicts between named volumes and mounts
+	for dest := range unifiedMounts {
+		if _, ok := unifiedVolumes[dest]; ok {
+			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
+		}
+	}
+	for dest := range unifiedVolumes {
+		if _, ok := unifiedMounts[dest]; ok {
+			return nil, nil, errors.Wrapf(errDuplicateDest, "conflict at mount destination %v", dest)
+		}
+	}
+
+	// Final step: maps to arrays
+	finalMounts := make([]spec.Mount, 0, len(unifiedMounts))
+	for _, mount := range unifiedMounts {
+		if mount.Type == TypeBind {
+			absSrc, err := filepath.Abs(mount.Source)
+			if err != nil {
+				return nil, nil, errors.Wrapf(err, "error getting absolute path of %s", mount.Source)
+			}
+			mount.Source = absSrc
+		}
+		finalMounts = append(finalMounts, mount)
+	}
+	finalVolumes := make([]*specgen.NamedVolume, 0, len(unifiedVolumes))
+	for _, volume := range unifiedVolumes {
+		finalVolumes = append(finalVolumes, volume)
+	}
+
+	return finalMounts, finalVolumes, nil
+}
+
+// getMounts takes user-provided input from the --mount flag and creates OCI
+// spec mounts and Libpod named volumes.
+// podman run --mount type=bind,src=/etc/resolv.conf,target=/etc/resolv.conf ...
+// podman run --mount type=tmpfs,target=/dev/shm ...
+// podman run --mount type=volume,source=test-volume, ...
+func getMounts(mountFlag []string) (map[string]spec.Mount, map[string]*specgen.NamedVolume, error) {
+	finalMounts := make(map[string]spec.Mount)
+	finalNamedVolumes := make(map[string]*specgen.NamedVolume)
+
+	errInvalidSyntax := errors.Errorf("incorrect mount format: should be --mount type=<bind|tmpfs|volume>,[src=<host-dir|volume-name>,]target=<ctr-dir>[,options]")
+
+	// TODO(vrothberg): the manual parsing can be replaced with a regular expression
+	//                  to allow a more robust parsing of the mount format and to give
+	//                  precise errors regarding supported format versus supported options.
+	for _, mount := range mountFlag {
+		arr := strings.SplitN(mount, ",", 2)
+		if len(arr) < 2 {
+			return nil, nil, errors.Wrapf(errInvalidSyntax, "%q", mount)
+		}
+		kv := strings.Split(arr[0], "=")
+		// TODO: type is not explicitly required in Docker.
+		// If not specified, it defaults to "volume".
+		if len(kv) != 2 || kv[0] != "type" {
+			return nil, nil, errors.Wrapf(errInvalidSyntax, "%q", mount)
+		}
+
+		tokens := strings.Split(arr[1], ",")
+		switch kv[1] {
+		case TypeBind:
+			mount, err := getBindMount(tokens)
+			if err != nil {
+				return nil, nil, err
+			}
+			if _, ok := finalMounts[mount.Destination]; ok {
+				return nil, nil, errors.Wrapf(errDuplicateDest, mount.Destination)
+			}
+			finalMounts[mount.Destination] = mount
+		case TypeTmpfs:
+			mount, err := getTmpfsMount(tokens)
+			if err != nil {
+				return nil, nil, err
+			}
+			if _, ok := finalMounts[mount.Destination]; ok {
+				return nil, nil, errors.Wrapf(errDuplicateDest, mount.Destination)
+			}
+			finalMounts[mount.Destination] = mount
+		case "volume":
+			volume, err := getNamedVolume(tokens)
+			if err != nil {
+				return nil, nil, err
+			}
+			if _, ok := finalNamedVolumes[volume.Dest]; ok {
+				return nil, nil, errors.Wrapf(errDuplicateDest, volume.Dest)
+			}
+			finalNamedVolumes[volume.Dest] = volume
+		default:
+			return nil, nil, errors.Errorf("invalid filesystem type %q", kv[1])
+		}
+	}
+
+	return finalMounts, finalNamedVolumes, nil
+}
+
+// Parse a single bind mount entry from the --mount flag.
+func getBindMount(args []string) (spec.Mount, error) {
+	newMount := spec.Mount{
+		Type: TypeBind,
+	}
+
+	var setSource, setDest, setRORW, setSuid, setDev, setExec, setRelabel bool
+
+	for _, val := range args {
+		kv := strings.Split(val, "=")
+		switch kv[0] {
+		case "bind-nonrecursive":
+			newMount.Options = append(newMount.Options, "bind")
+		case "ro", "rw":
+			if setRORW {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'ro' or 'rw' options more than once")
+			}
+			setRORW = true
+			// Can be formatted as one of:
+			// ro
+			// ro=[true|false]
+			// rw
+			// rw=[true|false]
+			switch len(kv) {
+			case 1:
+				newMount.Options = append(newMount.Options, kv[0])
+			case 2:
+				switch strings.ToLower(kv[1]) {
+				case "true":
+					newMount.Options = append(newMount.Options, kv[0])
+				case "false":
+					// Set the opposite only for rw
+					// ro's opposite is the default
+					if kv[0] == "rw" {
+						newMount.Options = append(newMount.Options, "ro")
+					}
+				default:
+					return newMount, errors.Wrapf(optionArgError, "%s must be set to true or false, instead received %q", kv[0], kv[1])
+				}
+			default:
+				return newMount, errors.Wrapf(optionArgError, "badly formatted option %q", val)
+			}
+		case "nosuid", "suid":
+			if setSuid {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'nosuid' and 'suid' options more than once")
+			}
+			setSuid = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "nodev", "dev":
+			if setDev {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'nodev' and 'dev' options more than once")
+			}
+			setDev = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "noexec", "exec":
+			if setExec {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'noexec' and 'exec' options more than once")
+			}
+			setExec = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "shared", "rshared", "private", "rprivate", "slave", "rslave", "Z", "z":
+			newMount.Options = append(newMount.Options, kv[0])
+		case "bind-propagation":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			newMount.Options = append(newMount.Options, kv[1])
+		case "src", "source":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			if err := parse.ValidateVolumeHostDir(kv[1]); err != nil {
+				return newMount, err
+			}
+			newMount.Source = kv[1]
+			setSource = true
+		case "target", "dst", "destination":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
+				return newMount, err
+			}
+			newMount.Destination = filepath.Clean(kv[1])
+			setDest = true
+		case "relabel":
+			if setRelabel {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'relabel' option more than once")
+			}
+			setRelabel = true
+			if len(kv) != 2 {
+				return newMount, errors.Wrapf(util.ErrBadMntOption, "%s mount option must be 'private' or 'shared'", kv[0])
+			}
+			switch kv[1] {
+			case "private":
+				newMount.Options = append(newMount.Options, "z")
+			case "shared":
+				newMount.Options = append(newMount.Options, "Z")
+			default:
+				return newMount, errors.Wrapf(util.ErrBadMntOption, "%s mount option must be 'private' or 'shared'", kv[0])
+			}
+		default:
+			return newMount, errors.Wrapf(util.ErrBadMntOption, kv[0])
+		}
+	}
+
+	if !setDest {
+		return newMount, noDestError
+	}
+
+	if !setSource {
+		newMount.Source = newMount.Destination
+	}
+
+	options, err := parse.ValidateVolumeOpts(newMount.Options)
+	if err != nil {
+		return newMount, err
+	}
+	newMount.Options = options
+	return newMount, nil
+}
+
+// Parse a single tmpfs mount entry from the --mount flag
+func getTmpfsMount(args []string) (spec.Mount, error) {
+	newMount := spec.Mount{
+		Type:   TypeTmpfs,
+		Source: TypeTmpfs,
+	}
+
+	var setDest, setRORW, setSuid, setDev, setExec, setTmpcopyup bool
+
+	for _, val := range args {
+		kv := strings.Split(val, "=")
+		switch kv[0] {
+		case "tmpcopyup", "notmpcopyup":
+			if setTmpcopyup {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'tmpcopyup' and 'notmpcopyup' options more than once")
+			}
+			setTmpcopyup = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "ro", "rw":
+			if setRORW {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'ro' and 'rw' options more than once")
+			}
+			setRORW = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "nosuid", "suid":
+			if setSuid {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'nosuid' and 'suid' options more than once")
+			}
+			setSuid = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "nodev", "dev":
+			if setDev {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'nodev' and 'dev' options more than once")
+			}
+			setDev = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "noexec", "exec":
+			if setExec {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'noexec' and 'exec' options more than once")
+			}
+			setExec = true
+			newMount.Options = append(newMount.Options, kv[0])
+		case "tmpfs-mode":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			newMount.Options = append(newMount.Options, fmt.Sprintf("mode=%s", kv[1]))
+		case "tmpfs-size":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			newMount.Options = append(newMount.Options, fmt.Sprintf("size=%s", kv[1]))
+		case "src", "source":
+			return newMount, errors.Errorf("source is not supported with tmpfs mounts")
+		case "target", "dst", "destination":
+			if len(kv) == 1 {
+				return newMount, errors.Wrapf(optionArgError, kv[0])
+			}
+			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
+				return newMount, err
+			}
+			newMount.Destination = filepath.Clean(kv[1])
+			setDest = true
+		default:
+			return newMount, errors.Wrapf(util.ErrBadMntOption, kv[0])
+		}
+	}
+
+	if !setDest {
+		return newMount, noDestError
+	}
+
+	return newMount, nil
+}
+
+// Parse a single volume mount entry from the --mount flag.
+// Note that the volume-label option for named volumes is currently NOT supported.
+// TODO: add support for --volume-label
+func getNamedVolume(args []string) (*specgen.NamedVolume, error) {
+	newVolume := new(specgen.NamedVolume)
+
+	var setSource, setDest, setRORW, setSuid, setDev, setExec bool
+
+	for _, val := range args {
+		kv := strings.Split(val, "=")
+		switch kv[0] {
+		case "ro", "rw":
+			if setRORW {
+				return nil, errors.Wrapf(optionArgError, "cannot pass 'ro' and 'rw' options more than once")
+			}
+			setRORW = true
+			newVolume.Options = append(newVolume.Options, kv[0])
+		case "nosuid", "suid":
+			if setSuid {
+				return nil, errors.Wrapf(optionArgError, "cannot pass 'nosuid' and 'suid' options more than once")
+			}
+			setSuid = true
+			newVolume.Options = append(newVolume.Options, kv[0])
+		case "nodev", "dev":
+			if setDev {
+				return nil, errors.Wrapf(optionArgError, "cannot pass 'nodev' and 'dev' options more than once")
+			}
+			setDev = true
+			newVolume.Options = append(newVolume.Options, kv[0])
+		case "noexec", "exec":
+			if setExec {
+				return nil, errors.Wrapf(optionArgError, "cannot pass 'noexec' and 'exec' options more than once")
+			}
+			setExec = true
+			newVolume.Options = append(newVolume.Options, kv[0])
+		case "volume-label":
+			return nil, errors.Errorf("the --volume-label option is not presently implemented")
+		case "src", "source":
+			if len(kv) == 1 {
+				return nil, errors.Wrapf(optionArgError, kv[0])
+			}
+			newVolume.Name = kv[1]
+			setSource = true
+		case "target", "dst", "destination":
+			if len(kv) == 1 {
+				return nil, errors.Wrapf(optionArgError, kv[0])
+			}
+			if err := parse.ValidateVolumeCtrDir(kv[1]); err != nil {
+				return nil, err
+			}
+			newVolume.Dest = filepath.Clean(kv[1])
+			setDest = true
+		default:
+			return nil, errors.Wrapf(util.ErrBadMntOption, kv[0])
+		}
+	}
+
+	if !setSource {
+		return nil, errors.Errorf("must set source volume")
+	}
+	if !setDest {
+		return nil, noDestError
+	}
+
+	return newVolume, nil
+}
+
+func getVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*specgen.NamedVolume, error) {
+	mounts := make(map[string]spec.Mount)
+	volumes := make(map[string]*specgen.NamedVolume)
+
+	volumeFormatErr := errors.Errorf("incorrect volume format, should be [host-dir:]ctr-dir[:option]")
+
+	for _, vol := range volumeFlag {
+		var (
+			options []string
+			src     string
+			dest    string
+			err     error
+		)
+
+		splitVol := strings.Split(vol, ":")
+		if len(splitVol) > 3 {
+			return nil, nil, errors.Wrapf(volumeFormatErr, vol)
+		}
+
+		src = splitVol[0]
+		if len(splitVol) == 1 {
+			// This is an anonymous named volume. Only thing given
+			// is destination.
+			// Name/source will be blank, and populated by libpod.
+			src = ""
+			dest = splitVol[0]
+		} else if len(splitVol) > 1 {
+			dest = splitVol[1]
+		}
+		if len(splitVol) > 2 {
+			if options, err = parse.ValidateVolumeOpts(strings.Split(splitVol[2], ",")); err != nil {
+				return nil, nil, err
+			}
+		}
+
+		// Do not check source dir for anonymous volumes
+		if len(splitVol) > 1 {
+			if err := parse.ValidateVolumeHostDir(src); err != nil {
+				return nil, nil, err
+			}
+		}
+		if err := parse.ValidateVolumeCtrDir(dest); err != nil {
+			return nil, nil, err
+		}
+
+		cleanDest := filepath.Clean(dest)
+
+		if strings.HasPrefix(src, "/") || strings.HasPrefix(src, ".") {
+			// This is not a named volume
+			newMount := spec.Mount{
+				Destination: cleanDest,
+				Type:        string(TypeBind),
+				Source:      src,
+				Options:     options,
+			}
+			if _, ok := mounts[newMount.Destination]; ok {
+				return nil, nil, errors.Wrapf(errDuplicateDest, newMount.Destination)
+			}
+			mounts[newMount.Destination] = newMount
+		} else {
+			// This is a named volume
+			newNamedVol := new(specgen.NamedVolume)
+			newNamedVol.Name = src
+			newNamedVol.Dest = cleanDest
+			newNamedVol.Options = options
+
+			if _, ok := volumes[newNamedVol.Dest]; ok {
+				return nil, nil, errors.Wrapf(errDuplicateDest, newNamedVol.Dest)
+			}
+			volumes[newNamedVol.Dest] = newNamedVol
+		}
+
+		logrus.Debugf("User mount %s:%s options %v", src, dest, options)
+	}
+
+	return mounts, volumes, nil
+}
+
+// GetTmpfsMounts creates spec.Mount structs for user-requested tmpfs mounts
+func getTmpfsMounts(tmpfsFlag []string) (map[string]spec.Mount, error) {
+	m := make(map[string]spec.Mount)
+	for _, i := range tmpfsFlag {
+		// Default options if nothing passed
+		var options []string
+		spliti := strings.Split(i, ":")
+		destPath := spliti[0]
+		if err := parse.ValidateVolumeCtrDir(spliti[0]); err != nil {
+			return nil, err
+		}
+		if len(spliti) > 1 {
+			options = strings.Split(spliti[1], ",")
+		}
+
+		if _, ok := m[destPath]; ok {
+			return nil, errors.Wrapf(errDuplicateDest, destPath)
+		}
+
+		mount := spec.Mount{
+			Destination: filepath.Clean(destPath),
+			Type:        string(TypeTmpfs),
+			Options:     options,
+			Source:      string(TypeTmpfs),
+		}
+		m[destPath] = mount
+	}
+	return m, nil
+}