Split container.go into three files

Weighing in at ~1700 lines, container.go is just too big. Split
it into three files: core structs and accessors (container.go),
public API (container_api.go), and internal functions
(container_internal.go).

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

1 files changed, 382 insertions, 0 deletions

diff --git a/libpod/container_internal.go b/libpod/container_internal.go
new file mode 100644
index 000000000..245246869
--- /dev/null
+++ b/libpod/container_internal.go
@@ -0,0 +1,382 @@
+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"
+)
+
+// 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(containerRuntimeInfo)
+
+	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
+}