cri-o/pkg/storage/runtime.go
Nalin Dahyabhai 3eca785331 Don't try to parse an image ID a second time
When looking for the image to use for creating a container, there's no
need to attempt parsing the ID a second time, and doing so can create
confusing error messages.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
2017-02-08 10:58:00 -05:00

460 lines
17 KiB
Go

package storage
import (
"encoding/json"
"errors"
"fmt"
"time"
"github.com/Sirupsen/logrus"
"github.com/containers/image/copy"
istorage "github.com/containers/image/storage"
"github.com/containers/image/transports"
"github.com/containers/image/types"
"github.com/containers/storage/storage"
"github.com/opencontainers/image-spec/specs-go/v1"
)
var (
// ErrInvalidPodName is returned when a pod name specified to a
// function call is found to be invalid (most often, because it's
// empty).
ErrInvalidPodName = errors.New("invalid pod name")
// ErrInvalidImageName is returned when an image name specified to a
// function call is found to be invalid (most often, because it's
// empty).
ErrInvalidImageName = errors.New("invalid image name")
// ErrInvalidContainerName is returned when a container name specified
// to a function call is found to be invalid (most often, because it's
// empty).
ErrInvalidContainerName = errors.New("invalid container name")
// ErrInvalidSandboxID is returned when a sandbox ID specified to a
// function call is found to be invalid (because it's either
// empty or doesn't match a valid sandbox).
ErrInvalidSandboxID = errors.New("invalid sandbox ID")
// ErrInvalidContainerID is returned when a container ID specified to a
// function call is found to be invalid (because it's either
// empty or doesn't match a valid container).
ErrInvalidContainerID = errors.New("invalid container ID")
)
type runtimeService struct {
image ImageServer
pauseImage string
}
// ContainerInfo wraps a subset of information about a container: its ID and
// the locations of its nonvolatile and volatile per-container directories,
// along with a copy of the configuration blob from the image that was used to
// create the container, if the image had a configuration.
type ContainerInfo struct {
ID string
Dir string
RunDir string
Config *v1.Image
}
// RuntimeServer wraps up various CRI-related activities into a reusable
// implementation.
type RuntimeServer interface {
// CreatePodSandbox creates a pod infrastructure container, using the
// specified PodID for the infrastructure container's ID. In the CRI
// view of things, a sandbox is distinct from its containers, including
// its infrastructure container, but at this level the sandbox is
// essentially the same as its infrastructure container, with a
// container's membership in a pod being signified by it listing the
// same pod ID in its metadata that the pod's other members do, and
// with the pod's infrastructure container having the same value for
// both its pod's ID and its container ID.
// Pointer arguments can be nil. Either the image name or ID can be
// omitted, but not both. All other arguments are required.
CreatePodSandbox(systemContext *types.SystemContext, podName, podID, imageName, imageID, containerName, metadataName, uid, namespace string, attempt uint32, copyOptions *copy.Options) (ContainerInfo, error)
// RemovePodSandbox deletes a pod sandbox's infrastructure container.
// The CRI expects that a sandbox can't be removed unless its only
// container is its infrastructure container, but we don't enforce that
// here, since we're just keeping track of it for higher level APIs.
RemovePodSandbox(idOrName string) error
// GetContainerMetadata returns the metadata we've stored for a container.
GetContainerMetadata(idOrName string) (RuntimeContainerMetadata, error)
// SetContainerMetadata updates the metadata we've stored for a container.
SetContainerMetadata(idOrName string, metadata RuntimeContainerMetadata) error
// CreateContainer creates a container with the specified ID.
// Pointer arguments can be nil. Either the image name or ID can be
// omitted, but not both. All other arguments are required.
CreateContainer(systemContext *types.SystemContext, podName, podID, imageName, imageID, containerName, containerID, metadataName string, attempt uint32, mountLabel string, copyOptions *copy.Options) (ContainerInfo, error)
// DeleteContainer deletes a container, unmounting it first if need be.
DeleteContainer(idOrName string) error
// StartContainer makes sure a container's filesystem is mounted, and
// returns the location of its root filesystem, which is not guaranteed
// by lower-level drivers to never change.
StartContainer(idOrName string) (string, error)
// StopContainer attempts to unmount a container's root filesystem,
// freeing up any kernel resources which may be limited.
StopContainer(idOrName string) error
// GetWorkDir returns the path of a nonvolatile directory on the
// filesystem (somewhere under the Store's Root directory) which can be
// used to store arbitrary data that is specific to the container. It
// will be removed automatically when the container is deleted.
GetWorkDir(id string) (string, error)
// GetRunDir returns the path of a volatile directory (does not survive
// the host rebooting, somewhere under the Store's RunRoot directory)
// on the filesystem which can be used to store arbitrary data that is
// specific to the container. It will be removed automatically when
// the container is deleted.
GetRunDir(id string) (string, error)
}
// RuntimeContainerMetadata is the structure that we encode as JSON and store
// in the metadata field of storage.Container objects. It is used for
// specifying attributes of pod sandboxes and containers when they are being
// created, and allows a container's MountLabel, and possibly other values, to
// be modified in one read/write cycle via calls to
// RuntimeServer.GetContainerMetadata, RuntimeContainerMetadata.SetMountLabel,
// and RuntimeServer.SetContainerMetadata.
type RuntimeContainerMetadata struct {
// Pod is true if this is the pod's infrastructure container.
Pod bool `json:"pod,omitempty"` // Applicable to both PodSandboxes and Containers
// The pod's name and ID, kept for use by upper layers in determining
// which containers belong to which pods.
PodName string `json:"pod-name"` // Applicable to both PodSandboxes and Containers, mandatory
PodID string `json:"pod-id"` // Applicable to both PodSandboxes and Containers, mandatory
// The provided name and the ID of the image that was used to
// instantiate the container.
ImageName string `json:"image-name"` // Applicable to both PodSandboxes and Containers
ImageID string `json:"image-id"` // Applicable to both PodSandboxes and Containers
// The container's name, which for an infrastructure container is usually PodName + "-infra".
ContainerName string `json:"name"` // Applicable to both PodSandboxes and Containers, mandatory
// The name as originally specified in PodSandbox or Container CRI metadata.
MetadataName string `json:"metadata-name"` // Applicable to both PodSandboxes and Containers, mandatory
UID string `json:"uid,omitempty"` // Only applicable to pods
Namespace string `json:"namespace,omitempty"` // Only applicable to pods
Attempt uint32 `json:"attempt,omitempty"` // Applicable to both PodSandboxes and Containers
CreatedAt int64 `json:"created-at"` // Applicable to both PodSandboxes and Containers
MountLabel string `json:"mountlabel,omitempty"` // Applicable to both PodSandboxes and Containers
}
// SetMountLabel updates the mount label held by a RuntimeContainerMetadata
// object.
func (metadata *RuntimeContainerMetadata) SetMountLabel(mountLabel string) {
metadata.MountLabel = mountLabel
}
func (r *runtimeService) createContainerOrPodSandbox(systemContext *types.SystemContext, podName, podID, imageName, imageID, containerName, containerID, metadataName, uid, namespace string, attempt uint32, mountLabel string, options *copy.Options) (ContainerInfo, error) {
var ref types.ImageReference
if podName == "" || podID == "" {
return ContainerInfo{}, ErrInvalidPodName
}
if imageName == "" && imageID == "" {
return ContainerInfo{}, ErrInvalidImageName
}
if containerName == "" {
return ContainerInfo{}, ErrInvalidContainerName
}
if metadataName == "" {
metadataName = containerName
}
// Check if we have the specified image.
ref, err := istorage.Transport.ParseStoreReference(r.image.GetStore(), imageName)
if err != nil {
// Maybe it's some other transport's copy of the image?
otherRef, err2 := transports.ParseImageName(imageName)
if err2 == nil && otherRef.DockerReference() != nil {
ref, err = istorage.Transport.ParseStoreReference(r.image.GetStore(), otherRef.DockerReference().FullName())
}
if err != nil {
// Maybe the image ID is sufficient?
ref, err = istorage.Transport.ParseStoreReference(r.image.GetStore(), "@"+imageID)
if err != nil {
return ContainerInfo{}, err
}
}
}
img, err := istorage.Transport.GetStoreImage(r.image.GetStore(), ref)
if img == nil && err == storage.ErrImageUnknown && imageName == r.pauseImage {
image := imageID
if imageName != "" {
image = imageName
}
if image == "" {
return ContainerInfo{}, ErrInvalidImageName
}
logrus.Debugf("couldn't find image %q, retrieving it", image)
ref, err = r.image.PullImage(systemContext, image, options)
if err != nil {
return ContainerInfo{}, err
}
img, err = istorage.Transport.GetStoreImage(r.image.GetStore(), ref)
if err != nil {
return ContainerInfo{}, err
}
logrus.Debugf("successfully pulled image %q", image)
}
if img == nil && err == storage.ErrImageUnknown {
if imageID == "" {
return ContainerInfo{}, fmt.Errorf("image %q not present in image store", imageName)
}
if imageName == "" {
return ContainerInfo{}, fmt.Errorf("image with ID %q not present in image store", imageID)
}
return ContainerInfo{}, fmt.Errorf("image %q with ID %q not present in image store", imageName, imageID)
}
// Pull out a copy of the image's configuration.
image, err := ref.NewImage(systemContext)
if err != nil {
return ContainerInfo{}, err
}
defer image.Close()
var imageConfig *v1.Image
configBlob, err := image.ConfigBlob()
if err != nil {
return ContainerInfo{}, err
}
if len(configBlob) > 0 {
config := v1.Image{}
err = json.Unmarshal(configBlob, &config)
if err != nil {
return ContainerInfo{}, err
}
imageConfig = &config
}
// Update the image name and ID.
if imageName == "" && len(img.Names) > 0 {
imageName = img.Names[0]
}
imageID = img.ID
// Build metadata to store with the container.
metadata := RuntimeContainerMetadata{
Pod: containerID == podID,
PodName: podName,
PodID: podID,
ImageName: imageName,
ImageID: imageID,
ContainerName: containerName,
MetadataName: metadataName,
UID: uid,
Namespace: namespace,
Attempt: attempt,
CreatedAt: time.Now().Unix(),
MountLabel: mountLabel,
}
mdata, err := json.Marshal(&metadata)
if err != nil {
return ContainerInfo{}, err
}
// Build the container.
names := []string{metadata.ContainerName}
if metadata.Pod {
names = append(names, metadata.PodName)
}
container, err := r.image.GetStore().CreateContainer(containerID, names, img.ID, "", string(mdata), nil)
if err != nil {
if metadata.Pod {
logrus.Debugf("failed to create pod sandbox %s(%s): %v", metadata.PodName, metadata.PodID, err)
} else {
logrus.Debugf("failed to create container %s(%s): %v", metadata.ContainerName, containerID, err)
}
return ContainerInfo{}, err
}
if metadata.Pod {
logrus.Debugf("created pod sandbox %q", container.ID)
} else {
logrus.Debugf("created container %q", container.ID)
}
// If anything fails after this point, we need to delete the incomplete
// container before returning.
defer func() {
if err != nil {
if err2 := r.image.GetStore().DeleteContainer(container.ID); err2 != nil {
if metadata.Pod {
logrus.Infof("%v deleting partially-created pod sandbox %q", err2, container.ID)
} else {
logrus.Infof("%v deleting partially-created container %q", err2, container.ID)
}
return
}
logrus.Infof("deleted partially-created container %q", container.ID)
}
}()
// Add a name to the container's layer so that it's easier to follow
// what's going on if we're just looking at the storage-eye view of things.
layerName := metadata.ContainerName + "-layer"
names, err = r.image.GetStore().GetNames(container.LayerID)
if err != nil {
return ContainerInfo{}, err
}
names = append(names, layerName)
err = r.image.GetStore().SetNames(container.LayerID, names)
if err != nil {
return ContainerInfo{}, err
}
// Find out where the container work directories are, so that we can return them.
containerDir, err := r.image.GetStore().GetContainerDirectory(container.ID)
if err != nil {
return ContainerInfo{}, err
}
if metadata.Pod {
logrus.Debugf("pod sandbox %q has work directory %q", container.ID, containerDir)
} else {
logrus.Debugf("container %q has work directory %q", container.ID, containerDir)
}
containerRunDir, err := r.image.GetStore().GetContainerRunDirectory(container.ID)
if err != nil {
return ContainerInfo{}, err
}
if metadata.Pod {
logrus.Debugf("pod sandbox %q has run directory %q", container.ID, containerRunDir)
} else {
logrus.Debugf("container %q has run directory %q", container.ID, containerRunDir)
}
return ContainerInfo{
ID: container.ID,
Dir: containerDir,
RunDir: containerRunDir,
Config: imageConfig,
}, nil
}
func (r *runtimeService) CreatePodSandbox(systemContext *types.SystemContext, podName, podID, imageName, imageID, containerName, metadataName, uid, namespace string, attempt uint32, copyOptions *copy.Options) (ContainerInfo, error) {
return r.createContainerOrPodSandbox(systemContext, podName, podID, imageName, imageID, containerName, podID, metadataName, uid, namespace, attempt, "", copyOptions)
}
func (r *runtimeService) CreateContainer(systemContext *types.SystemContext, podName, podID, imageName, imageID, containerName, containerID, metadataName string, attempt uint32, mountLabel string, copyOptions *copy.Options) (ContainerInfo, error) {
return r.createContainerOrPodSandbox(systemContext, podName, podID, imageName, imageID, containerName, containerID, metadataName, "", "", attempt, mountLabel, copyOptions)
}
func (r *runtimeService) RemovePodSandbox(idOrName string) error {
container, err := r.image.GetStore().GetContainer(idOrName)
if err != nil {
if err == storage.ErrContainerUnknown {
return ErrInvalidSandboxID
}
return err
}
err = r.image.GetStore().DeleteContainer(container.ID)
if err != nil {
logrus.Debugf("failed to delete pod sandbox %q: %v", container.ID, err)
return err
}
return nil
}
func (r *runtimeService) DeleteContainer(idOrName string) error {
container, err := r.image.GetStore().GetContainer(idOrName)
if err != nil {
if err == storage.ErrContainerUnknown {
return ErrInvalidContainerID
}
return err
}
err = r.image.GetStore().DeleteContainer(container.ID)
if err != nil {
logrus.Debugf("failed to delete container %q: %v", container.ID, err)
return err
}
return nil
}
func (r *runtimeService) SetContainerMetadata(idOrName string, metadata RuntimeContainerMetadata) error {
mdata, err := json.Marshal(&metadata)
if err != nil {
logrus.Debugf("failed to encode metadata for %q: %v", idOrName, err)
return err
}
return r.image.GetStore().SetMetadata(idOrName, string(mdata))
}
func (r *runtimeService) GetContainerMetadata(idOrName string) (RuntimeContainerMetadata, error) {
metadata := RuntimeContainerMetadata{}
mdata, err := r.image.GetStore().GetMetadata(idOrName)
if err != nil {
return metadata, err
}
if err = json.Unmarshal([]byte(mdata), &metadata); err != nil {
return metadata, err
}
return metadata, nil
}
func (r *runtimeService) StartContainer(idOrName string) (string, error) {
container, err := r.image.GetStore().GetContainer(idOrName)
if err != nil {
if err == storage.ErrContainerUnknown {
return "", ErrInvalidContainerID
}
return "", err
}
metadata := RuntimeContainerMetadata{}
if err = json.Unmarshal([]byte(container.Metadata), &metadata); err != nil {
return "", err
}
mountPoint, err := r.image.GetStore().Mount(container.ID, metadata.MountLabel)
if err != nil {
logrus.Debugf("failed to mount container %q: %v", container.ID, err)
return "", err
}
logrus.Debugf("mounted container %q at %q", container.ID, mountPoint)
return mountPoint, nil
}
func (r *runtimeService) StopContainer(idOrName string) error {
container, err := r.image.GetStore().GetContainer(idOrName)
if err != nil {
if err == storage.ErrContainerUnknown {
return ErrInvalidContainerID
}
return err
}
err = r.image.GetStore().Unmount(container.ID)
if err != nil {
logrus.Debugf("failed to unmount container %q: %v", container.ID, err)
return err
}
logrus.Debugf("unmounted container %q", container.ID)
return nil
}
func (r *runtimeService) GetWorkDir(id string) (string, error) {
container, err := r.image.GetStore().GetContainer(id)
if err != nil {
if err == storage.ErrContainerUnknown {
return "", ErrInvalidContainerID
}
return "", err
}
return r.image.GetStore().GetContainerDirectory(container.ID)
}
func (r *runtimeService) GetRunDir(id string) (string, error) {
container, err := r.image.GetStore().GetContainer(id)
if err != nil {
if err == storage.ErrContainerUnknown {
return "", ErrInvalidContainerID
}
return "", err
}
return r.image.GetStore().GetContainerRunDirectory(container.ID)
}
// GetRuntimeService returns a RuntimeServer that uses the passed-in image
// service to pull and manage images, and its store to manage containers based
// on those images.
func GetRuntimeService(image ImageServer, pauseImage string) RuntimeServer {
return &runtimeService{
image: image,
pauseImage: pauseImage,
}
}