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Refactor container code in preparation for saving state

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Also adds terminal handling code to libpod

Signed-off-by: Matthew Heon <mheon@redhat.com>
This commit is contained in:
Matthew Heon 2017-10-20 15:26:08 -04:00
parent 241653e152
commit 872c59da8f
4 changed files with 102 additions and 53 deletions
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109
libpod/container.go
View file

@ -42,24 +42,8 @@ type Container struct {
pod *Pod
runningSpec *spec.Spec
state ContainerState
// The location of the on-disk OCI runtime spec
specfilePath string
// Path to the nonvolatile container configuration file
statefilePath string
// Path to the container's non-volatile directory
containerDir string
// Path to the container's volatile directory
containerRunDir string
// Path to the mountpoint of the container's root filesystem
containerMountPoint string
// Whether this container was configured with containers/storage
useContainerStorage bool
// Containers/storage information on container
// Will be empty if container is configured using a directory
containerStorageInfo *ContainerInfo
state *containerRuntimeInfo
// TODO move to storage.Locker from sync.Mutex
valid bool
@ -67,20 +51,57 @@ type Container struct {
runtime *Runtime
}
// containerState contains the current state of the container
// It is stored as on disk in a per-boot directory
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"`
// TODO: Save information about image used in container if one is used
// TODO save start time, create time (create time in the containerConfig?)
}
// containerConfig contains all information that was used to create the
// container. It may not be changed once created.
// It is stored as an unchanging part of on-disk state
type containerConfig struct {
Spec *spec.Spec `json:"spec"`
ID string `json:"id"`
Name string `json:"name"`
RootfsDir *string `json:"rootfsDir,omitempty"`
RootfsImageID *string `json:"rootfsImageID,omitempty"`
RootfsImageName *string `json:"rootfsImageName,omitempty"`
UseImageConfig bool `json:"useImageConfig"`
Pod *string `json:"pod,omitempty"`
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"`
// Shared namespaces with container
SharedNamespaceCtr *string `json:"shareNamespacesWith,omitempty"`
SharedNamespaceMap map[string]string `json:"sharedNamespaces"`
// TODO save create time
// TODO save log location here and pass into OCI code
// TODO allow overriding of log path
}
// ID returns the container's ID
@ -113,7 +134,7 @@ func (c *Container) State() (ContainerState, error) {
// return ContainerStateUnknown, err
// }
return c.state, nil
return c.state.State, nil
}
// Make a new container
@ -124,6 +145,7 @@ func newContainer(rspec *spec.Spec) (*Container, error) {
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
@ -143,12 +165,12 @@ func (c *Container) setupStorage() error {
return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
}
if c.state != ContainerStateConfigured {
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.RootfsDir != nil {
if !c.config.RootfsFromImage {
// TODO implement directory-based root filesystems
return ErrNotImplemented
}
@ -160,20 +182,18 @@ func (c *Container) setupStorage() error {
// 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 == nil || c.config.RootfsImageName == nil {
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, "")
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.useContainerStorage = true
c.containerStorageInfo = &containerInfo
c.containerDir = containerInfo.Dir
c.containerRunDir = containerInfo.RunDir
c.config.StaticDir = containerInfo.Dir
c.state.RunDir = containerInfo.RunDir
return nil
}
@ -187,12 +207,12 @@ func (c *Container) Create() (err error) {
return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
}
if c.state != ContainerStateConfigured {
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.useContainerStorage {
if !c.config.RootfsFromImage {
// TODO implemented directory-based root filesystems
return ErrNotImplemented
} else {
@ -200,7 +220,8 @@ func (c *Container) Create() (err error) {
if err != nil {
return errors.Wrapf(err, "error mounting storage for container %s", c.ID())
}
c.containerMountPoint = mountPoint
c.state.Mounted = true
c.state.Mountpoint = mountPoint
defer func() {
if err != nil {
@ -208,7 +229,8 @@ func (c *Container) Create() (err error) {
logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err2)
}
c.containerMountPoint = ""
c.state.Mounted = false
c.state.Mountpoint = ""
}
}()
}
@ -216,12 +238,12 @@ func (c *Container) Create() (err error) {
// 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.containerMountPoint
c.runningSpec.Root.Path = c.state.Mountpoint
// TODO Add annotation for start time to spec
// Save the OCI spec to disk
jsonPath := filepath.Join(c.containerRunDir, "config.json")
jsonPath := filepath.Join(c.state.RunDir, "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())
@ -229,6 +251,7 @@ func (c *Container) Create() (err error) {
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
// With the spec complete, do an OCI create
// TODO set cgroup parent in a sane fashion
@ -237,7 +260,7 @@ func (c *Container) Create() (err error) {
}
// TODO should flush this state to disk here
c.state = ContainerStateCreated
c.state.State = ContainerStateCreated
return nil
}
@ -252,7 +275,7 @@ func (c *Container) Start() error {
}
// Container must be created or stopped to be started
if !(c.state == ContainerStateCreated || c.state == ContainerStateStopped) {
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())
}
@ -261,7 +284,7 @@ func (c *Container) Start() error {
}
// TODO should flush state to disk here
c.state = ContainerStateRunning
c.state.State = ContainerStateRunning
return nil
}

19
libpod/oci.go
View file

@ -1,6 +1,7 @@
package libpod
import (
"bytes"
"encoding/json"
"fmt"
"os"
@ -88,6 +89,8 @@ func createUnitName(prefix string, name string) string {
// TODO terminal support for container
// Presently just ignoring conmon opts related to it
func (r *OCIRuntime) createContainer(ctr *Container, cgroupParent string) error {
var stderrBuf bytes.Buffer
parentPipe, childPipe, err := newPipe()
if err != nil {
return errors.Wrapf(err, "error creating socket pair")
@ -108,12 +111,17 @@ func (r *OCIRuntime) createContainer(ctr *Container, cgroupParent string) error
args = append(args, "-c", ctr.ID())
args = append(args, "-u", ctr.ID())
args = append(args, "-r", r.path)
args = append(args, "-b", ctr.containerRunDir)
args = append(args, "-p", filepath.Join(ctr.containerRunDir, "pidfile"))
args = append(args, "-b", ctr.state.RunDir)
args = append(args, "-p", filepath.Join(ctr.state.RunDir, "pidfile"))
// TODO container log location should be configurable
// The default also likely shouldn't be this
args = append(args, "-l", filepath.Join(ctr.containerDir, "ctr.log"))
args = append(args, "-l", filepath.Join(ctr.config.StaticDir, "ctr.log"))
args = append(args, "--exit-dir", r.exitsDir)
if ctr.config.Spec.Process.Terminal {
args = append(args, "-t")
} else if ctr.config.Stdin {
args = append(args, "-i")
}
if r.logSizeMax >= 0 {
args = append(args, "--log-size-max", fmt.Sprintf("%v", r.logSizeMax))
}
@ -125,7 +133,7 @@ func (r *OCIRuntime) createContainer(ctr *Container, cgroupParent string) error
}).Debugf("running conmon: %s", r.conmonPath)
cmd := exec.Command(r.conmonPath, args...)
cmd.Dir = ctr.containerRunDir
cmd.Dir = ctr.state.RunDir
cmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
}
@ -134,6 +142,9 @@ func (r *OCIRuntime) createContainer(ctr *Container, cgroupParent string) error
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if ctr.config.Spec.Process.Terminal {
cmd.Stderr = &stderrBuf
}
cmd.ExtraFiles = append(cmd.ExtraFiles, childPipe, childStartPipe)
// 0, 1 and 2 are stdin, stdout and stderr

25
libpod/options.go
View file

@ -229,11 +229,12 @@ func WithRootFSFromPath(path string) CtrCreateOption {
return ErrCtrFinalized
}
if ctr.config.RootfsDir != nil || ctr.config.RootfsImageID != nil || ctr.config.RootfsImageName != nil {
if ctr.config.RootfsDir != "" || ctr.config.RootfsImageID != "" || ctr.config.RootfsImageName != "" {
return fmt.Errorf("container already configured to with rootfs")
}
ctr.config.RootfsDir = &path
ctr.config.RootfsDir = path
ctr.config.RootfsFromImage = false
return nil
}
@ -249,13 +250,27 @@ func WithRootFSFromImage(imageID string, imageName string, useImageConfig bool)
return ErrCtrFinalized
}
if ctr.config.RootfsDir != nil || ctr.config.RootfsImageID != nil || ctr.config.RootfsImageName != nil {
if ctr.config.RootfsDir != "" || ctr.config.RootfsImageID != "" || ctr.config.RootfsImageName != "" {
return fmt.Errorf("container already configured to with rootfs")
}
ctr.config.RootfsImageID = &imageID
ctr.config.RootfsImageName = &imageName
ctr.config.RootfsImageID = imageID
ctr.config.RootfsImageName = imageName
ctr.config.UseImageConfig = useImageConfig
ctr.config.RootfsFromImage = true
return nil
}
}
// WithStdin keeps stdin on the container open to allow interaction
func WithStdin() CtrCreateOption {
return func(ctr *Container) error {
if ctr.valid {
return ErrCtrFinalized
}
ctr.config.Stdin = true
return nil
}

2
libpod/runtime_ctr.go
View file

@ -38,7 +38,7 @@ func (r *Runtime) NewContainer(spec *spec.Spec, options ...CtrCreateOption) (*Co
}
ctr.valid = true
ctr.state = ContainerStateConfigured
ctr.state.State = ContainerStateConfigured
ctr.runtime = r
if err := ctr.setupStorage(); err != nil {