Implementation of SQL-backed state

cmd/kpod/run.go

@@ -83,7 +83,7 @@ func runCmd(c *cli.Context) error {
 	}
 
 	logrus.Debug("new container created ", ctr.ID())
-	if err := ctr.Create(); err != nil {
+	if err := ctr.Init(); err != nil {
 		return err
 	}
 	logrus.Debug("container storage created for %q", ctr.ID())

libpod/container.go

@@ -87,21 +87,17 @@ type containerConfig struct {
 	Spec *spec.Spec `json:"spec"`
 	ID   string     `json:"id"`
 	Name string     `json:"name"`
-	// RootfsFromImage indicates whether the container uses a root
-	// filesystem from an image, or from a user-provided directory
-	RootfsFromImage bool
-	// Directory used as a root filesystem if not configured with an image
-	RootfsDir string `json:"rootfsDir,omitempty"`
 	// Information on the image used for the root filesystem
 	RootfsImageID   string `json:"rootfsImageID,omitempty"`
 	RootfsImageName string `json:"rootfsImageName,omitempty"`
-	MountLabel      string `json:"MountLabel,omitempty"`
 	UseImageConfig  bool   `json:"useImageConfig"`
-	// Whether to keep container STDIN open
-	Stdin bool
+	// SELinux mount label for root filesystem
+	MountLabel string `json:"MountLabel,omitempty"`
 	// Static directory for container content that will persist across
 	// reboot
 	StaticDir string `json:"staticDir"`
+	// Whether to keep container STDIN open
+	Stdin bool
 	// Pod the container belongs to
 	Pod string `json:"pod,omitempty"`
 	// Labels is a set of key-value pairs providing additional information
@@ -154,10 +150,9 @@ func (c *Container) State() (ContainerState, error) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	// TODO uncomment when working
-	// if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil {
-	// 	return ContainerStateUnknown, err
-	// }
+	if err := c.runtime.state.UpdateContainer(c); err != nil {
+		return ContainerStateUnknown, errors.Wrapf(err, "error updating container %s state", c.ID())
+	}
 
 	return c.state.State, nil
 }
@@ -207,18 +202,6 @@ func (c *Container) setupStorage() error {
 		return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Configured state to have storage set up", c.ID())
 	}
 
-	// If we're configured to use a directory, perform that setup
-	if !c.config.RootfsFromImage {
-		// TODO implement directory-based root filesystems
-		return ErrNotImplemented
-	}
-
-	// Not using a directory, so call into containers/storage
-	return c.setupImageRootfs()
-}
-
-// Set up an image as root filesystem using containers/storage
-func (c *Container) setupImageRootfs() error {
 	// Need both an image ID and image name, plus a bool telling us whether to use the image configuration
 	if c.config.RootfsImageID == "" || c.config.RootfsImageName == "" {
 		return errors.Wrapf(ErrInvalidArg, "must provide image ID and image name to use an image")
@@ -248,16 +231,6 @@ func (c *Container) teardownStorage() error {
 		return errors.Wrapf(ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID())
 	}
 
-	if !c.config.RootfsFromImage {
-		// TODO implement directory-based root filesystems
-		return ErrNotImplemented
-	}
-
-	return c.teardownImageRootfs()
-}
-
-// Completely remove image-based root filesystem for a container
-func (c *Container) teardownImageRootfs() error {
 	if c.state.Mounted {
 		if err := c.runtime.storageService.StopContainer(c.ID()); err != nil {
 			return errors.Wrapf(err, "error unmounting container %s root filesystem", c.ID())
@@ -273,11 +246,15 @@ func (c *Container) teardownImageRootfs() error {
 	return nil
 }
 
-// Create creates a container in the OCI runtime
-func (c *Container) Create() (err error) {
+// Init creates a container in the OCI runtime
+func (c *Container) Init() (err error) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
+	if err := c.runtime.state.UpdateContainer(c); err != nil {
+		return errors.Wrapf(err, "error updating container %s state", c.ID())
+	}
+
 	if !c.valid {
 		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
 	}
@@ -286,33 +263,25 @@ func (c *Container) Create() (err error) {
 		return errors.Wrapf(ErrCtrExists, "container %s has already been created in runtime", c.ID())
 	}
 
-	// If using containers/storage, mount the container
-	if !c.config.RootfsFromImage {
-		// TODO implement directory-based root filesystems
-		if !c.state.Mounted {
-			return ErrNotImplemented
-		}
-	} else {
-		mountPoint, err := c.runtime.storageService.StartContainer(c.ID())
-		if err != nil {
-			return errors.Wrapf(err, "error mounting storage for container %s", c.ID())
-		}
-		c.state.Mounted = true
-		c.state.Mountpoint = mountPoint
-
-		logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)
+	mountPoint, err := c.runtime.storageService.StartContainer(c.ID())
+	if err != nil {
+		return errors.Wrapf(err, "error mounting storage for container %s", c.ID())
+	}
+	c.state.Mounted = true
+	c.state.Mountpoint = mountPoint
 
-		defer func() {
-			if err != nil {
-				if err2 := c.runtime.storageService.StopContainer(c.ID()); err2 != nil {
-					logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err2)
-				}
+	logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)
 
-				c.state.Mounted = false
-				c.state.Mountpoint = ""
+	defer func() {
+		if err != nil {
+			if err2 := c.runtime.storageService.StopContainer(c.ID()); err2 != nil {
+				logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err2)
 			}
-		}()
-	}
+
+			c.state.Mounted = false
+			c.state.Mountpoint = ""
+		}
+	}()
 
 	// Make the OCI runtime spec we will use
 	c.runningSpec = new(spec.Spec)
@@ -342,9 +311,12 @@ func (c *Container) Create() (err error) {
 
 	logrus.Debugf("Created container %s in runc", c.ID())
 
-	// TODO should flush this state to disk here
 	c.state.State = ContainerStateCreated
 
+	if err := c.runtime.state.SaveContainer(c); err != nil {
+		return errors.Wrapf(err, "error saving container %s state", c.ID())
+	}
+
 	return nil
 }
 
@@ -353,6 +325,10 @@ func (c *Container) Start() error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
+	if err := c.runtime.state.UpdateContainer(c); err != nil {
+		return errors.Wrapf(err, "error updating container %s state", c.ID())
+	}
+
 	if !c.valid {
 		return ErrCtrRemoved
 	}
@@ -368,10 +344,13 @@ func (c *Container) Start() error {
 
 	logrus.Debugf("Started container %s", c.ID())
 
-	// TODO should flush state to disk here
 	c.state.StartedTime = time.Now()
 	c.state.State = ContainerStateRunning
 
+	if err := c.runtime.state.SaveContainer(c); err != nil {
+		return errors.Wrapf(err, "error saving container %s state", c.ID())
+	}
+
 	return nil
 }
 
@@ -394,6 +373,25 @@ func (c *Container) Exec(cmd []string, tty bool, stdin bool) (string, error) {
 // Attach attaches to a container
 // Returns fully qualified URL of streaming server for the container
 func (c *Container) Attach(noStdin bool, keys string, attached chan<- bool) error {
+	if err := c.runtime.state.UpdateContainer(c); err != nil {
+		return errors.Wrapf(err, "error updating container %s state", c.ID())
+	}
+
+	if !c.valid {
+		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
+	}
+
+	if c.state.State == ContainerStateRunning || c.state.State == ContainerStatePaused {
+		return errors.Wrapf(ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID())
+	}
+
+	// TODO is it valid to attach to a frozen container?
+	if c.state.State == ContainerStateUnknown ||
+		c.state.State == ContainerStateConfigured ||
+		c.state.State == ContainerStatePaused {
+		return errors.Wrapf(ErrCtrStateInvalid, "can only attach to created, running, or stopped containers")
+	}
+
 	// Check the validity of the provided keys first
 	var err error
 	detachKeys := []byte{}
@@ -403,25 +401,12 @@ func (c *Container) Attach(noStdin bool, keys string, attached chan<- bool) erro
 			return errors.Wrapf(err, "invalid detach keys")
 		}
 	}
-	cStatus := c.state.State
 
-	if !(cStatus == ContainerStateRunning || cStatus == ContainerStateCreated) {
-		return errors.Errorf("%s is not created or running", c.Name())
-	}
 	resize := make(chan remotecommand.TerminalSize)
 	defer close(resize)
-	err = c.attachContainerSocket(resize, noStdin, detachKeys, attached)
 
+	err = c.attachContainerSocket(resize, noStdin, detachKeys, attached)
 	return err
-
-	// TODO
-	// Re-enable this when mheon is done wth it
-	//if err != nil {
-	//	return err
-	//}
-	//c.ContainerStateToDisk(c)
-
-	//return err
 }
 
 // Mount mounts a container's filesystem on the host
@@ -448,10 +433,6 @@ func (c *Container) Export(path string) error {
 
 // Commit commits the changes between a container and its image, creating a new
 // image
-// If the container was not created from an image (for example,
-// WithRootFSFromPath will create a container from a directory on the system),
-// a new base image will be created from the contents of the container's
-// filesystem
 func (c *Container) Commit() (*storage.Image, error) {
 	return nil, ErrNotImplemented
 }

libpod/errors.go

@@ -56,6 +56,10 @@ var (
 	// further operations can be performed on it
 	ErrPodRemoved = errors.New("pod has already been removed")
 
+	// ErrDBClosed indicates that the connection to the state database has
+	// already been closed
+	ErrDBClosed = errors.New("database connection already closed")
+
 	// ErrNotImplemented indicates that the requested functionality is not
 	// yet present
 	ErrNotImplemented = errors.New("not yet implemented")

libpod/in_memory_state.go

@@ -32,6 +32,12 @@ func NewInMemoryState() (State, error) {
 	return state, nil
 }
 
+// Close the state before shutdown
+// This is a no-op as we have no backing disk
+func (s *InMemoryState) Close() error {
+	return nil
+}
+
 // Container retrieves a container from its full ID
 func (s *InMemoryState) Container(id string) (*Container, error) {
 	if id == "" {
@@ -147,6 +153,21 @@ func (s *InMemoryState) RemoveContainer(ctr *Container) error {
 	return nil
 }
 
+// UpdateContainer updates a container's state
+// As all state is in-memory, no update will be required
+// As such this is a no-op
+func (s *InMemoryState) UpdateContainer(ctr *Container) error {
+	return nil
+}
+
+// SaveContainer saves a container's state
+// As all state is in-memory, any changes are always reflected as soon as they
+// are made
+// As such this is a no-op
+func (s *InMemoryState) SaveContainer(ctr *Container) error {
+	return nil
+}
+
 // AllContainers retrieves all containers from the state
 func (s *InMemoryState) AllContainers() ([]*Container, error) {
 	ctrs := make([]*Container, 0, len(s.containers))

libpod/options.go

@@ -94,6 +94,20 @@ func WithSignaturePolicy(path string) RuntimeOption {
 	}
 }
 
+// WithInMemoryState specifies that the runtime will be backed by an in-memory
+// state only, and state will not persist after the runtime is shut down
+func WithInMemoryState() RuntimeOption {
+	return func(rt *Runtime) error {
+		if rt.valid {
+			return ErrRuntimeFinalized
+		}
+
+		rt.config.InMemoryState = true
+
+		return nil
+	}
+}
+
 // WithOCIRuntime specifies an OCI runtime to use for running containers
 func WithOCIRuntime(runtimePath string) RuntimeOption {
 	return func(rt *Runtime) error {
@@ -236,25 +250,6 @@ func WithNoPivotRoot(noPivot bool) RuntimeOption {
 
 // Container Creation Options
 
-// WithRootFSFromPath uses the given path as a container's root filesystem
-// No further setup is performed on this path
-func WithRootFSFromPath(path string) CtrCreateOption {
-	return func(ctr *Container) error {
-		if ctr.valid {
-			return ErrCtrFinalized
-		}
-
-		if ctr.config.RootfsDir != "" || ctr.config.RootfsImageID != "" || ctr.config.RootfsImageName != "" {
-			return errors.Wrapf(ErrInvalidArg, "container already configured with root filesystem")
-		}
-
-		ctr.config.RootfsDir = path
-		ctr.config.RootfsFromImage = false
-
-		return nil
-	}
-}
-
 // WithSELinuxMountLabel sets the mount label for SELinux
 func WithSELinuxMountLabel(mountLabel string) CtrCreateOption {
 	return func(ctr *Container) error {
@@ -277,14 +272,13 @@ func WithRootFSFromImage(imageID string, imageName string, useImageConfig bool)
 			return ErrCtrFinalized
 		}
 
-		if ctr.config.RootfsDir != "" || ctr.config.RootfsImageID != "" || ctr.config.RootfsImageName != "" {
+		if ctr.config.RootfsImageID != "" || ctr.config.RootfsImageName != "" {
 			return errors.Wrapf(ErrInvalidArg, "container already configured with root filesystem")
 		}
 
 		ctr.config.RootfsImageID = imageID
 		ctr.config.RootfsImageName = imageName
 		ctr.config.UseImageConfig = useImageConfig
-		ctr.config.RootfsFromImage = true
 
 		return nil
 	}