Add --mount option for create & run command

Signed-off-by: Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Closes: #1524
Approved by: mheon

cmd/podman/common.go

@@ -417,6 +417,10 @@ var createFlags = []cli.Flag{
 		Name:  "uts",
 		Usage: "UTS namespace to use",
 	},
+	cli.StringSliceFlag{
+		Name:  "mount",
+		Usage: "Attach a filesystem mount to the container (default [])",
+	},
 	cli.StringSliceFlag{
 		Name:  "volume, v",
 		Usage: "Bind mount a volume into the container (default [])",

cmd/podman/create.go

@@ -24,6 +24,7 @@ import (
 	"github.com/docker/docker/pkg/signal"
 	"github.com/docker/go-connections/nat"
 	"github.com/docker/go-units"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/opencontainers/selinux/go-selinux/label"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -459,6 +460,10 @@ func parseCreateOpts(ctx context.Context, c *cli.Context, runtime *libpod.Runtim
 		}
 		blkioWeight = uint16(u)
 	}
+	var mountList []spec.Mount
+	if mountList, err = parseMounts(c.StringSlice("mount")); err != nil {
+		return nil, err
+	}
 
 	if err = parseVolumes(c.StringSlice("volume")); err != nil {
 		return nil, err
@@ -772,6 +777,7 @@ func parseCreateOpts(ctx context.Context, c *cli.Context, runtime *libpod.Runtim
 		Tty:         tty,
 		User:        user,
 		UsernsMode:  usernsMode,
+		Mounts:      mountList,
 		Volumes:     c.StringSlice("volume"),
 		WorkDir:     workDir,
 		Rootfs:      rootfs,

cmd/podman/create_cli.go

@@ -8,6 +8,8 @@ import (
 
 	cc "github.com/containers/libpod/pkg/spec"
 	"github.com/docker/docker/pkg/sysinfo"
+	"github.com/docker/go-units"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -74,6 +76,94 @@ func addWarning(warnings []string, msg string) []string {
 	return append(warnings, msg)
 }
 
+// Format supported.
+// podman run --mount type=bind,src=/etc/resolv.conf,target=/etc/resolv.conf ...
+// podman run --mount type=tmpfs,target=/dev/shm ..
+func parseMounts(mounts []string) ([]spec.Mount, error) {
+	var mountList []spec.Mount
+	errInvalidSyntax := errors.Errorf("incorrect mount format : should be --mount type=<bind|tmpfs>,[src=<host-dir>,]target=<ctr-dir>,[options]")
+	for _, mount := range mounts {
+		var tokenCount int
+		var mountInfo spec.Mount
+
+		arr := strings.SplitN(mount, ",", 2)
+		if len(arr) < 2 {
+			return nil, errInvalidSyntax
+		}
+		kv := strings.Split(arr[0], "=")
+		if kv[0] != "type" {
+			return nil, errInvalidSyntax
+		}
+		switch kv[1] {
+		case "bind":
+			mountInfo.Type = string(cc.TypeBind)
+		case "tmpfs":
+			mountInfo.Type = string(cc.TypeTmpfs)
+			mountInfo.Source = string(cc.TypeTmpfs)
+			mountInfo.Options = append(mountInfo.Options, []string{"rprivate", "noexec", "nosuid", "nodev", "size=65536k"}...)
+
+		default:
+			return nil, errors.Errorf("invalid filesystem type %q", kv[1])
+		}
+
+		tokens := strings.Split(arr[1], ",")
+		for i, val := range tokens {
+			if i == (tokenCount - 1) {
+				//Parse tokens before options.
+				break
+			}
+			kv := strings.Split(val, "=")
+			switch kv[0] {
+			case "ro", "nosuid", "nodev", "noexec":
+				mountInfo.Options = append(mountInfo.Options, kv[0])
+			case "shared", "rshared", "private", "rprivate", "slave", "rslave", "Z", "z":
+				if mountInfo.Type != "bind" {
+					return nil, errors.Errorf("%s can only be used with bind mounts", kv[0])
+				}
+				mountInfo.Options = append(mountInfo.Options, kv[0])
+			case "tmpfs-mode":
+				if mountInfo.Type != "tmpfs" {
+					return nil, errors.Errorf("%s can only be used with tmpfs mounts", kv[0])
+				}
+				mountInfo.Options = append(mountInfo.Options, fmt.Sprintf("mode=%s", kv[1]))
+			case "tmpfs-size":
+				if mountInfo.Type != "tmpfs" {
+					return nil, errors.Errorf("%s can only be used with tmpfs mounts", kv[0])
+				}
+				shmSize, err := units.FromHumanSize(kv[1])
+				if err != nil {
+					return nil, errors.Wrapf(err, "unable to translate tmpfs-size")
+				}
+
+				mountInfo.Options = append(mountInfo.Options, fmt.Sprintf("size=%d", shmSize))
+
+			case "bind-propagation":
+				if mountInfo.Type != "bind" {
+					return nil, errors.Errorf("%s can only be used with bind mounts", kv[0])
+				}
+				mountInfo.Options = append(mountInfo.Options, kv[1])
+			case "src", "source":
+				if mountInfo.Type == "tmpfs" {
+					return nil, errors.Errorf("can not use src= on a tmpfs file system")
+				}
+				if err := validateVolumeHostDir(kv[1]); err != nil {
+					return nil, err
+				}
+				mountInfo.Source = kv[1]
+			case "target", "dst", "destination":
+				if err := validateVolumeCtrDir(kv[1]); err != nil {
+					return nil, err
+				}
+				mountInfo.Destination = kv[1]
+			default:
+				return nil, errors.Errorf("incorrect mount option : %s", kv[0])
+			}
+		}
+		mountList = append(mountList, mountInfo)
+	}
+	return mountList, nil
+}
+
 func parseVolumes(volumes []string) error {
 	for _, volume := range volumes {
 		arr := strings.SplitN(volume, ":", 3)

completions/bash/podman

@@ -945,6 +945,7 @@ _podman_build() {
      --userns-uid-map-user
      --userns-gid-map-group
      --uts
+     --mount
      --volume
      -v
   "

docs/podman-create.1.md

@@ -372,6 +372,36 @@ unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap.
 
 Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
 
+**--mount**=*type=TYPE,TYPE-SPECIFIC-OPTION[,...]*
+
+Attach a filesystem mount to the container
+
+Current supported mount TYPES are bind, and tmpfs.
+
+       e.g.
+
+       type=bind,source=/path/on/host,destination=/path/in/container
+
+       type=tmpfs,tmpfs-size=512M,destination=/path/in/container
+
+       Common Options:
+
+              · src, source: mount source spec for bind and volume. Mandatory for bind.
+
+              · dst, destination, target: mount destination spec.
+
+              · ro, read-only: true or false (default).
+
+       Options specific to bind:
+
+              · bind-propagation: shared, slave, private, rshared, rslave, or rprivate(default). See also mount(2).
+
+       Options specific to tmpfs:
+
+              · tmpfs-size: Size of the tmpfs mount in bytes. Unlimited by default in Linux.
+
+              · tmpfs-mode: File mode of the tmpfs in octal. (e.g. 700 or 0700.) Defaults to 1777 in Linux.
+
 **--name**=""
 
 Assign a name to the container

docs/podman-run.1.md

@@ -655,6 +655,36 @@ Set the UTS mode for the container
 
 **NOTE**: the host mode gives the container access to changing the host's hostname and is therefore considered insecure.
 
+**--mount**=*type=TYPE,TYPE-SPECIFIC-OPTION[,...]*
+
+Attach a filesystem mount to the container
+
+Current supported mount TYPES are bind, and tmpfs.
+
+       e.g.
+
+       type=bind,source=/path/on/host,destination=/path/in/container
+
+       type=tmpfs,tmpfs-size=512M,destination=/path/in/container
+
+       Common Options:
+
+              · src, source: mount source spec for bind and volume. Mandatory for bind.
+
+              · dst, destination, target: mount destination spec.
+
+              · ro, read-only: true or false (default).
+
+       Options specific to bind:
+
+              · bind-propagation: Z, z, shared, slave, private, rshared, rslave, or rprivate(default). See also mount(2).
+
+       Options specific to tmpfs:
+
+              · tmpfs-size: Size of the tmpfs mount in bytes. Unlimited by default in Linux.
+
+              · tmpfs-mode: File mode of the tmpfs in octal. (e.g. 700 or 0700.) Defaults to 1777 in Linux.
+
 **-v**|**--volume**[=*[HOST-DIR:CONTAINER-DIR[:OPTIONS]]*]
 
 Create a bind mount. If you specify, ` -v /HOST-DIR:/CONTAINER-DIR`, podman
@@ -931,6 +961,12 @@ colon:
 $ podman run -v /var/db:/data1 -i -t fedora bash
 ```
 
+Using --mount flags, To mount a host directory as a container folder, specify
+the absolute path to the directory and the absolute path for the container
+directory:
+
+$ podman run --mount type=bind,src=/var/db,target=/data1 busybox sh
+
 When using SELinux, be aware that the host has no knowledge of container SELinux
 policy. Therefore, in the above example, if SELinux policy is enforced, the
 `/var/db` directory is not writable to the container. A "Permission Denied"
@@ -1030,6 +1066,8 @@ $ podman run --uidmap 0:30000:7000 --gidmap 0:30000:7000 fedora echo hello
 subgid(5), subuid(5), libpod.conf(5)
 
 ## HISTORY
+September 2018, updated by Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>
+
 October 2017, converted from Docker documentation to podman by Dan Walsh for podman <dwalsh@redhat.com>
 
 November 2015, updated by Sally O'Malley <somalley@redhat.com>

libpod/container_internal.go

@@ -926,6 +926,9 @@ func (c *Container) makeBindMounts() error {
 	if err != nil {
 		return errors.Wrapf(err, "error creating resolv.conf for container %s", c.ID())
 	}
+	if err = label.Relabel(newResolv, c.config.MountLabel, false); err != nil {
+		return errors.Wrapf(err, "error relabeling %q for container %q", newResolv, c.ID)
+	}
 	c.state.BindMounts["/etc/resolv.conf"] = newResolv
 
 	// Make /etc/hosts
@@ -937,6 +940,9 @@ func (c *Container) makeBindMounts() error {
 	if err != nil {
 		return errors.Wrapf(err, "error creating hosts file for container %s", c.ID())
 	}
+	if err = label.Relabel(newHosts, c.config.MountLabel, false); err != nil {
+		return errors.Wrapf(err, "error relabeling %q for container %q", newHosts, c.ID)
+	}
 	c.state.BindMounts["/etc/hosts"] = newHosts
 
 	// Make /etc/hostname
@@ -946,6 +952,9 @@ func (c *Container) makeBindMounts() error {
 		if err != nil {
 			return errors.Wrapf(err, "error creating hostname file for container %s", c.ID())
 		}
+		if err = label.Relabel(hostnamePath, c.config.MountLabel, false); err != nil {
+			return errors.Wrapf(err, "error relabeling %q for container %q", hostnamePath, c.ID)
+		}
 		c.state.BindMounts["/etc/hostname"] = hostnamePath
 	}
 

libpod/container_internal_linux.go

@@ -283,6 +283,13 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
 	mounts := sortMounts(g.Mounts())
 	g.ClearMounts()
 	for _, m := range mounts {
+		switch m.Type {
+		case "tmpfs", "devpts":
+			o := label.FormatMountLabel("", c.config.MountLabel)
+			if o != "" {
+				m.Options = append(m.Options, o)
+			}
+		}
 		g.AddMount(m)
 	}
 	return g.Config, nil

pkg/spec/createconfig.go

@@ -122,6 +122,7 @@ type CreateConfig struct {
 	UsernsMode         namespaces.UsernsMode //userns
 	User               string                //user
 	UtsMode            namespaces.UTSMode    //uts
+	Mounts             []spec.Mount          //mounts
 	Volumes            []string              //volume
 	VolumesFrom        []string
 	WorkDir            string   //workdir
@@ -142,54 +143,59 @@ func (c *CreateConfig) CreateBlockIO() (*spec.LinuxBlockIO, error) {
 	return c.createBlockIO()
 }
 
+func processOptions(options []string) []string {
+	var (
+		foundrw, foundro bool
+		rootProp         string
+	)
+	options = append(options, "rbind")
+	for _, opt := range options {
+		switch opt {
+		case "rw":
+			foundrw = true
+		case "ro":
+			foundro = true
+		case "private", "rprivate", "slave", "rslave", "shared", "rshared":
+			rootProp = opt
+		}
+	}
+	if !foundrw && !foundro {
+		options = append(options, "rw")
+	}
+	if rootProp == "" {
+		options = append(options, "rprivate")
+	}
+	return options
+}
+
+func (c *CreateConfig) initFSMounts() []spec.Mount {
+	var mounts []spec.Mount
+	for _, m := range c.Mounts {
+		m.Options = processOptions(m.Options)
+		if m.Type == "tmpfs" {
+			m.Options = append(m.Options, "tmpcopyup")
+		} else {
+			mounts = append(mounts, m)
+		}
+	}
+	return mounts
+}
+
 //GetVolumeMounts takes user provided input for bind mounts and creates Mount structs
 func (c *CreateConfig) GetVolumeMounts(specMounts []spec.Mount) ([]spec.Mount, error) {
 	var m []spec.Mount
 	for _, i := range c.Volumes {
-		var (
+		var options []string
-			options                          []string
-			foundrw, foundro, foundz, foundZ bool
-			rootProp                         string
-		)
-
-		// We need to handle SELinux options better here, specifically :Z
 		spliti := strings.Split(i, ":")
 		if len(spliti) > 2 {
 			options = strings.Split(spliti[2], ",")
 		}
-		options = append(options, "rbind")
-		for _, opt := range options {
-			switch opt {
-			case "rw":
-				foundrw = true
-			case "ro":
-				foundro = true
-			case "z":
-				foundz = true
-			case "Z":
-				foundZ = true
-			case "private", "rprivate", "slave", "rslave", "shared", "rshared":
-				rootProp = opt
-			}
-		}
-		if !foundrw && !foundro {
-			options = append(options, "rw")
-		}
-		if foundz {
-			options = append(options, "z")
-		}
-		if foundZ {
-			options = append(options, "Z")
-		}
-		if rootProp == "" {
-			options = append(options, "rprivate")
-		}
 
 		m = append(m, spec.Mount{
 			Destination: spliti[1],
 			Type:        string(TypeBind),
 			Source:      spliti[0],
-			Options:     options,
+			Options:     processOptions(options),
 		})
 
 		logrus.Debugf("User mount %s:%s options %v", spliti[0], spliti[1], options)

pkg/spec/spec.go

@@ -18,6 +18,34 @@ import (
 
 const cpuPeriod = 100000
 
+func supercedeUserMounts(mounts []spec.Mount, configMount []spec.Mount) []spec.Mount {
+	if len(mounts) > 0 {
+		// If we have overlappings mounts, remove them from the spec in favor of
+		// the user-added volume mounts
+		destinations := make(map[string]bool)
+		for _, mount := range mounts {
+			destinations[path.Clean(mount.Destination)] = true
+		}
+		// Copy all mounts from spec to defaultMounts, except for
+		//  - mounts overridden by a user supplied mount;
+		//  - all mounts under /dev if a user supplied /dev is present;
+		mountDev := destinations["/dev"]
+		for _, mount := range configMount {
+			if _, ok := destinations[path.Clean(mount.Destination)]; !ok {
+				if mountDev && strings.HasPrefix(mount.Destination, "/dev/") {
+					// filter out everything under /dev if /dev is user-mounted
+					continue
+				}
+
+				logrus.Debugf("Adding mount %s", mount.Destination)
+				mounts = append(mounts, mount)
+			}
+		}
+		return mounts
+	}
+	return configMount
+}
+
 // CreateConfigToOCISpec parses information needed to create a container into an OCI runtime spec
 func CreateConfigToOCISpec(config *CreateConfig) (*spec.Spec, error) { //nolint
 	cgroupPerm := "ro"
@@ -246,6 +274,12 @@ func CreateConfigToOCISpec(config *CreateConfig) (*spec.Spec, error) { //nolint
 		g.AddMount(tmpfsMnt)
 	}
 
+	for _, m := range config.Mounts {
+		if m.Type == "tmpfs" {
+			g.AddMount(m)
+		}
+	}
+
 	for name, val := range config.Env {
 		g.AddProcessEnv(name, val)
 	}
@@ -305,36 +339,14 @@ func CreateConfigToOCISpec(config *CreateConfig) (*spec.Spec, error) { //nolint
 		return nil, errors.Wrap(err, "error getting volume mounts from --volumes-from flag")
 	}
 
-	mounts, err := config.GetVolumeMounts(configSpec.Mounts)
+	volumeMounts, err := config.GetVolumeMounts(configSpec.Mounts)
 	if err != nil {
 		return nil, errors.Wrapf(err, "error getting volume mounts")
 	}
-	if len(mounts) > 0 {
-		// If we have overlappings mounts, remove them from the spec in favor of
-		// the user-added volume mounts
-		destinations := make(map[string]bool)
-		for _, mount := range mounts {
-			destinations[path.Clean(mount.Destination)] = true
-		}
-
-		// Copy all mounts from spec to defaultMounts, except for
-		//  - mounts overridden by a user supplied mount;
-		//  - all mounts under /dev if a user supplied /dev is present;
-		mountDev := destinations["/dev"]
-		for _, mount := range configSpec.Mounts {
-			if _, ok := destinations[path.Clean(mount.Destination)]; !ok {
-				if mountDev && strings.HasPrefix(mount.Destination, "/dev/") {
-					// filter out everything under /dev if /dev is user-mounted
-					continue
-				}
-
-				logrus.Debugf("Adding mount %s", mount.Destination)
-				mounts = append(mounts, mount)
-			}
-		}
-		configSpec.Mounts = mounts
-	}
 
+	configSpec.Mounts = supercedeUserMounts(volumeMounts, configSpec.Mounts)
+	//--mount
+	configSpec.Mounts = supercedeUserMounts(config.initFSMounts(), configSpec.Mounts)
 	if canAddResources {
 		// BLOCK IO
 		blkio, err := config.CreateBlockIO()

test/e2e/run_test.go

@@ -234,6 +234,32 @@ var _ = Describe("Podman run", func() {
 		Expect(session.OutputToString()).To(ContainSubstring("/run/test rw,relatime, shared"))
 	})
 
+	It("podman run with mount flag", func() {
+		mountPath := filepath.Join(podmanTest.TempDir, "secrets")
+		os.Mkdir(mountPath, 0755)
+		session := podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test rw"))
+
+		session = podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test,ro", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test ro"))
+
+		session = podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test,shared", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test rw,relatime shared"))
+
+		mountPath = filepath.Join(podmanTest.TempDir, "scratchpad")
+		os.Mkdir(mountPath, 0755)
+		session = podmanTest.Podman([]string{"run", "--rm", "--mount", "type=tmpfs,target=/run/test", ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test rw,nosuid,nodev,noexec,relatime - tmpfs"))
+	})
+
 	It("podman run with cidfile", func() {
 		session := podmanTest.Podman([]string{"run", "--cidfile", tempdir + "cidfile", ALPINE, "ls"})
 		session.WaitWithDefaultTimeout()
@@ -565,6 +591,19 @@ USER mail`
 		Expect(session.ExitCode()).To(Equal(0))
 	})
 
+	It("podman run --mount flag with multiple mounts", func() {
+		vol1 := filepath.Join(podmanTest.TempDir, "vol-test1")
+		err := os.MkdirAll(vol1, 0755)
+		Expect(err).To(BeNil())
+		vol2 := filepath.Join(podmanTest.TempDir, "vol-test2")
+		err = os.MkdirAll(vol2, 0755)
+		Expect(err).To(BeNil())
+
+		session := podmanTest.Podman([]string{"run", "--mount", "type=bind,src=" + vol1 + ",target=/myvol1,z", "--mount", "type=bind,src=" + vol2 + ",target=/myvol2,z", ALPINE, "touch", "/myvol2/foo.txt"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+
 	It("podman run findmnt nothing shared", func() {
 		vol1 := filepath.Join(podmanTest.TempDir, "vol-test1")
 		err := os.MkdirAll(vol1, 0755)