Merge pull request #1 from mheon/master

Initial checkin

1 files changed, 428 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
new file mode 100644
index 000000000..1f5be9477
--- /dev/null
+++ b/libpod/container.go
@@ -0,0 +1,428 @@
+package libpod
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/containers/storage"
+	"github.com/docker/docker/pkg/stringid"
+	crioAnnotations "github.com/projectatomic/libpod/pkg/annotations"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/ulule/deepcopier"
+)
+
+// ContainerState represents the current state of a container
+type ContainerState int
+
+const (
+	// ContainerStateUnknown indicates that the container is in an error
+	// state where information about it cannot be retrieved
+	ContainerStateUnknown ContainerState = iota
+	// ContainerStateConfigured indicates that the container has had its
+	// storage configured but it has not been created in the OCI runtime
+	ContainerStateConfigured ContainerState = iota
+	// ContainerStateCreated indicates the container has been created in
+	// the OCI runtime but not started
+	ContainerStateCreated ContainerState = iota
+	// ContainerStateRunning indicates the container is currently executing
+	ContainerStateRunning ContainerState = iota
+	// ContainerStateStopped indicates that the container was running but has
+	// exited
+	ContainerStateStopped ContainerState = iota
+	// ContainerStatePaused indicates that the container has been paused
+	ContainerStatePaused ContainerState = iota
+)
+
+// Container is a single OCI container
+type Container struct {
+	config *containerConfig
+
+	pod         *Pod
+	runningSpec *spec.Spec
+
+	state *containerRuntimeInfo
+
+	// TODO move to storage.Locker from sync.Mutex
+	valid   bool
+	lock    sync.Mutex
+	runtime *Runtime
+}
+
+// containerState contains the current state of the container
+// It is stored on disk in a tmpfs and recreated on reboot
+type containerRuntimeInfo struct {
+	// The current state of the running container
+	State ContainerState `json:"state"`
+	// The path to the JSON OCI runtime spec for this container
+	ConfigPath string `json:"configPath,omitempty"`
+	// RunDir is a per-boot directory for container content
+	RunDir string `json:"runDir,omitempty"`
+	// Mounted indicates whether the container's storage has been mounted
+	// for use
+	Mounted bool `json:"-"`
+	// MountPoint contains the path to the container's mounted storage
+	Mountpoint string `json:"mountPoint,omitempty"`
+	// StartedTime is the time the container was started
+	StartedTime time.Time `json:"startedTime,omitempty"`
+	// FinishedTime is the time the container finished executing
+	FinishedTime time.Time `json:"finishedTime,omitempty"`
+	// ExitCode is the exit code returned when the container stopped
+	ExitCode int32 `json:"exitCode,omitempty"`
+
+	// TODO: Save information about image used in container if one is used
+}
+
+// containerConfig contains all information that was used to create the
+// container. It may not be changed once created.
+// It is stored, read-only, on disk
+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"`
+	UseImageConfig  bool   `json:"useImageConfig"`
+	// Whether to keep container STDIN open
+	Stdin bool
+	// Static directory for container content that will persist across
+	// reboot
+	StaticDir string `json:"staticDir"`
+	// Pod the container belongs to
+	Pod string `json:"pod,omitempty"`
+	// Labels is a set of key-value pairs providing additional information
+	// about a container
+	Labels map[string]string `json:"labels,omitempty"`
+	// StopSignal is the signal that will be used to stop the container
+	StopSignal uint `json:"stopSignal,omitempty"`
+	// Shared namespaces with container
+	SharedNamespaceCtr *string           `json:"shareNamespacesWith,omitempty"`
+	SharedNamespaceMap map[string]string `json:"sharedNamespaces"`
+	// Time container was created
+	CreatedTime time.Time `json:"createdTime"`
+
+	// TODO save log location here and pass into OCI code
+	// TODO allow overriding of log path
+}
+
+// ID returns the container's ID
+func (c *Container) ID() string {
+	return c.config.ID
+}
+
+// Name returns the container's name
+func (c *Container) Name() string {
+	return c.config.Name
+}
+
+// Spec returns the container's OCI runtime spec
+// The spec returned is the one used to create the container. The running
+// spec may differ slightly as mounts are added based on the image
+func (c *Container) Spec() *spec.Spec {
+	spec := new(spec.Spec)
+	deepcopier.Copy(c.config.Spec).To(spec)
+
+	return spec
+}
+
+// Labels returns the container's labels
+func (c *Container) Labels() map[string]string {
+	labels := make(map[string]string)
+	for key, value := range c.config.Labels {
+		labels[key] = value
+	}
+
+	return labels
+}
+
+// State returns the current state of the container
+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
+	// }
+
+	return c.state.State, nil
+}
+
+// The path to the container's root filesystem - where the OCI spec will be
+// placed, amongst other things
+func (c *Container) bundlePath() string {
+	return c.state.RunDir
+}
+
+// Retrieves the path of the container's attach socket
+func (c *Container) attachSocketPath() string {
+	return filepath.Join(c.runtime.ociRuntime.socketsDir, c.ID(), "attach")
+}
+
+// Make a new container
+func newContainer(rspec *spec.Spec) (*Container, error) {
+	if rspec == nil {
+		return nil, errors.Wrapf(ErrInvalidArg, "must provide a valid runtime spec to create container")
+	}
+
+	ctr := new(Container)
+	ctr.config = new(containerConfig)
+	ctr.state = new(containerRuntimeInfo)
+
+	ctr.config.ID = stringid.GenerateNonCryptoID()
+	ctr.config.Name = ctr.config.ID // TODO generate unique human-readable names
+
+	ctr.config.Spec = new(spec.Spec)
+	deepcopier.Copy(rspec).To(ctr.config.Spec)
+
+	ctr.config.CreatedTime = time.Now()
+
+	return ctr, nil
+}
+
+// Create container root filesystem for use
+func (c *Container) setupStorage() error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if !c.valid {
+		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
+	}
+
+	if c.state.State != ContainerStateConfigured {
+		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")
+	}
+
+	// TODO SELinux mount label
+	containerInfo, err := c.runtime.storageService.CreateContainerStorage(c.runtime.imageContext, c.config.RootfsImageName, c.config.RootfsImageID, c.config.Name, c.config.ID, "")
+	if err != nil {
+		return errors.Wrapf(err, "error creating container storage")
+	}
+
+	c.config.StaticDir = containerInfo.Dir
+	c.state.RunDir = containerInfo.RunDir
+
+	return nil
+}
+
+// Tear down a container's storage prior to removal
+func (c *Container) teardownStorage() error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	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())
+	}
+
+	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())
+		}
+
+		c.state.Mounted = false
+	}
+
+	if err := c.runtime.storageService.DeleteContainer(c.ID()); err != nil {
+		return errors.Wrapf(err, "error removing container %s root filesystem", c.ID())
+	}
+
+	return nil
+}
+
+// Create creates a container in the OCI runtime
+func (c *Container) Create() (err error) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if !c.valid {
+		return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
+	}
+
+	if c.state.State != ContainerStateConfigured {
+		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)
+
+		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)
+	deepcopier.Copy(c.config.Spec).To(c.runningSpec)
+	c.runningSpec.Root.Path = c.state.Mountpoint
+	c.runningSpec.Annotations[crioAnnotations.Created] = c.config.CreatedTime.Format(time.RFC3339Nano)
+	c.runningSpec.Annotations["org.opencontainers.image.stopSignal"] = fmt.Sprintf("%d", c.config.StopSignal)
+
+	// Save the OCI spec to disk
+	jsonPath := filepath.Join(c.bundlePath(), "config.json")
+	fileJSON, err := json.Marshal(c.runningSpec)
+	if err != nil {
+		return errors.Wrapf(err, "error exporting runtime spec for container %s to JSON", c.ID())
+	}
+	if err := ioutil.WriteFile(jsonPath, fileJSON, 0644); err != nil {
+		return errors.Wrapf(err, "error writing runtime spec JSON to file for container %s", c.ID())
+	}
+	c.state.ConfigPath = jsonPath
+
+	logrus.Debugf("Created OCI spec for container %s at %s", c.ID(), jsonPath)
+
+	// With the spec complete, do an OCI create
+	// TODO set cgroup parent in a sane fashion
+	if err := c.runtime.ociRuntime.createContainer(c, "/libpod_parent"); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Created container %s in runc", c.ID())
+
+	// TODO should flush this state to disk here
+	c.state.State = ContainerStateCreated
+
+	return nil
+}
+
+// Start starts a container
+func (c *Container) Start() error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if !c.valid {
+		return ErrCtrRemoved
+	}
+
+	// Container must be created or stopped to be started
+	if !(c.state.State == ContainerStateCreated || c.state.State == ContainerStateStopped) {
+		return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Created or Stopped state to be started", c.ID())
+	}
+
+	if err := c.runtime.ociRuntime.startContainer(c); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Started container %s", c.ID())
+
+	// TODO should flush state to disk here
+	c.state.StartedTime = time.Now()
+	c.state.State = ContainerStateRunning
+
+	return nil
+}
+
+// Stop stops a container
+func (c *Container) Stop() error {
+	return ErrNotImplemented
+}
+
+// Kill sends a signal to a container
+func (c *Container) Kill(signal uint) error {
+	return ErrNotImplemented
+}
+
+// Exec starts a new process inside the container
+// Returns fully qualified URL of streaming server for executed process
+func (c *Container) Exec(cmd []string, tty bool, stdin bool) (string, error) {
+	return "", ErrNotImplemented
+}
+
+// Attach attaches to a container
+// Returns fully qualified URL of streaming server for the container
+func (c *Container) Attach(stdin, tty bool) (string, error) {
+	return "", ErrNotImplemented
+}
+
+// Mount mounts a container's filesystem on the host
+// The path where the container has been mounted is returned
+func (c *Container) Mount() (string, error) {
+	return "", ErrNotImplemented
+}
+
+// Pause pauses a container
+func (c *Container) Pause() error {
+	return ErrNotImplemented
+}
+
+// Unpause unpauses a container
+func (c *Container) Unpause() error {
+	return ErrNotImplemented
+}
+
+// Export exports a container's root filesystem as a tar archive
+// The archive will be saved as a file at the given path
+func (c *Container) Export(path string) error {
+	return ErrNotImplemented
+}
+
+// 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
+}