Files
podman/libpod/container_internal.go
Matthew Heon ae2ffc31d3 Fix gofmt
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
2018-01-18 11:59:38 -05:00

388 lines
12 KiB
Go

package libpod
import (
"fmt"
"io"
"os"
"path/filepath"
"syscall"
"time"
"github.com/containers/storage"
"github.com/containers/storage/pkg/archive"
"github.com/docker/docker/pkg/mount"
"github.com/docker/docker/pkg/namesgenerator"
"github.com/docker/docker/pkg/stringid"
"github.com/mrunalp/fileutils"
spec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/opencontainers/selinux/go-selinux/label"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"github.com/ulule/deepcopier"
"golang.org/x/sys/unix"
)
const (
// name of the directory holding the artifacts
artifactsDir = "artifacts"
)
// rootFsSize gets the size of the container's root filesystem
// A container FS is split into two parts. The first is the top layer, a
// mutable layer, and the rest is the RootFS: the set of immutable layers
// that make up the image on which the container is based.
func (c *Container) rootFsSize() (int64, error) {
container, err := c.runtime.store.Container(c.ID())
if err != nil {
return 0, err
}
// Ignore the size of the top layer. The top layer is a mutable RW layer
// and is not considered a part of the rootfs
rwLayer, err := c.runtime.store.Layer(container.LayerID)
if err != nil {
return 0, err
}
layer, err := c.runtime.store.Layer(rwLayer.Parent)
if err != nil {
return 0, err
}
size := int64(0)
for layer.Parent != "" {
layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID)
if err != nil {
return size, errors.Wrapf(err, "getting diffsize of layer %q and its parent %q", layer.ID, layer.Parent)
}
size += layerSize
layer, err = c.runtime.store.Layer(layer.Parent)
if err != nil {
return 0, err
}
}
// Get the size of the last layer. Has to be outside of the loop
// because the parent of the last layer is "", andlstore.Get("")
// will return an error.
layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID)
return size + layerSize, err
}
// rwSize Gets the size of the mutable top layer of the container.
func (c *Container) rwSize() (int64, error) {
container, err := c.runtime.store.Container(c.ID())
if err != nil {
return 0, err
}
// Get the size of the top layer by calculating the size of the diff
// between the layer and its parent. The top layer of a container is
// the only RW layer, all others are immutable
layer, err := c.runtime.store.Layer(container.LayerID)
if err != nil {
return 0, err
}
return c.runtime.store.DiffSize(layer.Parent, layer.ID)
}
// 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.config.StaticDir
}
// The path to the container's logs file
func (c *Container) logPath() string {
return filepath.Join(c.config.StaticDir, "ctr.log")
}
// Retrieves the path of the container's attach socket
func (c *Container) attachSocketPath() string {
return filepath.Join(c.runtime.ociRuntime.socketsDir, c.ID(), "attach")
}
// Sync this container with on-disk state and runc status
// Should only be called with container lock held
// This function should suffice to ensure a container's state is accurate and
// it is valid for use.
func (c *Container) syncContainer() error {
if err := c.runtime.state.UpdateContainer(c); err != nil {
return err
}
// If runc knows about the container, update its status in runc
// And then save back to disk
if (c.state.State != ContainerStateUnknown) &&
(c.state.State != ContainerStateConfigured) {
oldState := c.state.State
// TODO: optionally replace this with a stat for the exit file
if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil {
return err
}
// Only save back to DB if state changed
if c.state.State != oldState {
if err := c.save(); err != nil {
return err
}
}
}
if !c.valid {
return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID())
}
return nil
}
// Make a new container
func newContainer(rspec *spec.Spec, lockDir string) (*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(containerState)
ctr.config.ID = stringid.GenerateNonCryptoID()
ctr.config.Name = namesgenerator.GetRandomName(0)
ctr.config.Spec = new(spec.Spec)
deepcopier.Copy(rspec).To(ctr.config.Spec)
ctr.config.CreatedTime = time.Now()
ctr.config.ShmSize = DefaultShmSize
ctr.config.CgroupParent = CgroupParent
// Path our lock file will reside at
lockPath := filepath.Join(lockDir, ctr.config.ID)
// Grab a lockfile at the given path
lock, err := storage.GetLockfile(lockPath)
if err != nil {
return nil, errors.Wrapf(err, "error creating lockfile for new container")
}
ctr.lock = lock
return ctr, nil
}
// Create container root filesystem for use
func (c *Container) setupStorage() error {
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())
}
// 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")
}
containerInfo, err := c.runtime.storageService.CreateContainerStorage(c.runtime.imageContext, c.config.RootfsImageName, c.config.RootfsImageID, c.config.Name, c.config.ID, c.config.MountLabel)
if err != nil {
return errors.Wrapf(err, "error creating container storage")
}
c.config.StaticDir = containerInfo.Dir
c.state.RunDir = containerInfo.RunDir
artifacts := filepath.Join(c.config.StaticDir, artifactsDir)
if err := os.MkdirAll(artifacts, 0755); err != nil {
return errors.Wrapf(err, "error creating artifacts directory %q", artifacts)
}
return nil
}
// Tear down a container's storage prior to removal
func (c *Container) teardownStorage() error {
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())
}
artifacts := filepath.Join(c.config.StaticDir, artifactsDir)
if err := os.RemoveAll(artifacts); err != nil {
return errors.Wrapf(err, "error removing artifacts %q", artifacts)
}
if err := c.cleanupStorage(); err != nil {
return errors.Wrapf(err, "failed to cleanup container %s storage", c.ID())
}
if err := c.runtime.storageService.DeleteContainer(c.ID()); err != nil {
return errors.Wrapf(err, "error removing container %s root filesystem", c.ID())
}
return nil
}
// Refresh refreshes the container's state after a restart
func (c *Container) refresh() error {
c.lock.Lock()
defer c.lock.Unlock()
if !c.valid {
return errors.Wrapf(ErrCtrRemoved, "container %s is not valid - may have been removed", c.ID())
}
// We need to get the container's temporary directory from c/storage
// It was lost in the reboot and must be recreated
dir, err := c.runtime.storageService.GetRunDir(c.ID())
if err != nil {
return errors.Wrapf(err, "error retrieving temporary directory for container %s", c.ID())
}
c.state.RunDir = dir
if err := c.runtime.state.SaveContainer(c); err != nil {
return errors.Wrapf(err, "error refreshing state for container %s", c.ID())
}
return nil
}
func (c *Container) export(path string) error {
mountPoint := c.state.Mountpoint
if !c.state.Mounted {
mount, err := c.runtime.store.Mount(c.ID(), c.config.MountLabel)
if err != nil {
return errors.Wrapf(err, "error mounting container %q", c.ID())
}
mountPoint = mount
defer func() {
if err := c.runtime.store.Unmount(c.ID()); err != nil {
logrus.Errorf("error unmounting container %q: %v", c.ID(), err)
}
}()
}
input, err := archive.Tar(mountPoint, archive.Uncompressed)
if err != nil {
return errors.Wrapf(err, "error reading container directory %q", c.ID())
}
outFile, err := os.Create(path)
if err != nil {
return errors.Wrapf(err, "error creating file %q", path)
}
defer outFile.Close()
_, err = io.Copy(outFile, input)
return err
}
// Get path of artifact with a given name for this container
func (c *Container) getArtifactPath(name string) string {
return filepath.Join(c.config.StaticDir, artifactsDir, name)
}
// Used with Wait() to determine if a container has exited
func (c *Container) isStopped() (bool, error) {
if !c.locked {
c.lock.Lock()
defer c.lock.Unlock()
}
err := c.syncContainer()
if err != nil {
return true, err
}
return c.state.State == ContainerStateStopped, nil
}
// save container state to the database
func (c *Container) save() error {
if err := c.runtime.state.SaveContainer(c); err != nil {
return errors.Wrapf(err, "error saving container %s state", c.ID())
}
return nil
}
// mountStorage sets up the container's root filesystem
// It mounts the image and any other requested mounts
// TODO: Add ability to override mount label so we can use this for Mount() too
// TODO: Can we use this for export? Copying SHM into the export might not be
// good
func (c *Container) mountStorage() (err error) {
// Container already mounted, nothing to do
if c.state.Mounted {
return nil
}
// TODO: generalize this mount code so it will mount every mount in ctr.config.Mounts
mounted, err := mount.Mounted(c.config.ShmDir)
if err != nil {
return errors.Wrapf(err, "unable to determine if %q is mounted", c.config.ShmDir)
}
if !mounted {
shmOptions := fmt.Sprintf("mode=1777,size=%d", c.config.ShmSize)
if err := unix.Mount("shm", c.config.ShmDir, "tmpfs", unix.MS_NOEXEC|unix.MS_NOSUID|unix.MS_NODEV,
label.FormatMountLabel(shmOptions, c.config.MountLabel)); err != nil {
return errors.Wrapf(err, "failed to mount shm tmpfs %q", c.config.ShmDir)
}
}
mountPoint, err := c.runtime.storageService.MountContainerImage(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.cleanupStorage(); err2 != nil {
logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err)
}
}
}()
return c.save()
}
// cleanupStorage unmounts and cleans up the container's root filesystem
func (c *Container) cleanupStorage() error {
if !c.state.Mounted {
// Already unmounted, do nothing
return nil
}
for _, mount := range c.config.Mounts {
if err := unix.Unmount(mount, unix.MNT_DETACH); err != nil {
if err != syscall.EINVAL {
logrus.Warnf("container %s failed to unmount %s : %v", c.ID(), mount, err)
}
}
}
// Also unmount storage
if err := c.runtime.storageService.UnmountContainerImage(c.ID()); err != nil {
return errors.Wrapf(err, "error unmounting container %s root filesystem", c.ID())
}
c.state.Mountpoint = ""
c.state.Mounted = false
return c.save()
}
// copyHostFileToRundir copies the provided file to the runtimedir
func (c *Container) copyHostFileToRundir(sourcePath string) (string, error) {
destFileName := filepath.Join(c.state.RunDir, filepath.Base(sourcePath))
if err := fileutils.CopyFile(sourcePath, destFileName); err != nil {
return "", err
}
// Relabel runDirResolv for the container
if err := label.Relabel(destFileName, c.config.MountLabel, false); err != nil {
return "", err
}
return destFileName, nil
}