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

2 files changed, 79 insertions, 61 deletions

diff --git a/pkg/spec/createconfig.go b/pkg/spec/createconfig.go
index a9c7d2967..887ef8e95 100644
--- a/pkg/spec/createconfig.go
+++ b/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 (
-			options                          []string
-			foundrw, foundro, foundz, foundZ bool
-			rootProp                         string
-		)
-
-		// We need to handle SELinux options better here, specifically :Z
+		var options []string
 		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)
diff --git a/pkg/spec/spec.go b/pkg/spec/spec.go
index e115bba7f..ad14ea65d 100644
--- a/pkg/spec/spec.go
+++ b/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()