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, 754 insertions, 0 deletions

diff --git a/libpod/container_api.go b/libpod/container_api.go
new file mode 100644
index 000000000..9a4f50079
--- /dev/null
+++ b/libpod/container_api.go
@@ -0,0 +1,754 @@
+package libpod
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/docker/docker/daemon/caps"
+	"github.com/docker/docker/pkg/stringid"
+	"github.com/docker/docker/pkg/term"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/opencontainers/runtime-tools/generate"
+	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/libpod/driver"
+	crioAnnotations "github.com/projectatomic/libpod/pkg/annotations"
+	"github.com/projectatomic/libpod/pkg/chrootuser"
+	"github.com/sirupsen/logrus"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/tools/remotecommand"
+)
+
+// Init creates a container in the OCI runtime
+func (c *Container) Init() (err error) {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	if c.state.State != ContainerStateConfigured {
+		return errors.Wrapf(ErrCtrExists, "container %s has already been created in runtime", c.ID())
+	}
+
+	if err := c.mountStorage(); err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if err2 := c.cleanupStorage(); err2 != nil {
+				logrus.Errorf("Error cleaning up storage for container %s: %v", c.ID(), err2)
+			}
+		}
+	}()
+
+	// Make a network namespace for the container
+	if c.config.CreateNetNS && c.state.NetNS == nil {
+		if err := c.runtime.createNetNS(c); err != nil {
+			return err
+		}
+	}
+	defer func() {
+		if err != nil {
+			if err2 := c.runtime.teardownNetNS(c); err2 != nil {
+				logrus.Errorf("Error tearing down network namespace for container %s: %v", c.ID(), err2)
+			}
+		}
+	}()
+
+	// If the OCI spec already exists, we need to replace it
+	// Cannot guarantee some things, e.g. network namespaces, have the same
+	// paths
+	jsonPath := filepath.Join(c.bundlePath(), "config.json")
+	if _, err := os.Stat(jsonPath); err != nil {
+		if !os.IsNotExist(err) {
+			return errors.Wrapf(err, "error doing stat on container %s spec", c.ID())
+		}
+		// The spec does not exist, we're fine
+	} else {
+		// The spec exists, need to remove it
+		if err := os.Remove(jsonPath); err != nil {
+			return errors.Wrapf(err, "error replacing runtime spec for container %s", c.ID())
+		}
+	}
+
+	// Copy /etc/resolv.conf to the container's rundir
+	resolvPath := "/etc/resolv.conf"
+
+	// Check if the host system is using system resolve and if so
+	// copy its resolv.conf
+	_, err = os.Stat("/run/systemd/resolve/resolv.conf")
+	if err == nil {
+		resolvPath = "/run/systemd/resolve/resolv.conf"
+	}
+	runDirResolv, err := c.copyHostFileToRundir(resolvPath)
+	if err != nil {
+		return errors.Wrapf(err, "unable to copy resolv.conf to ", runDirResolv)
+	}
+	// Copy /etc/hosts to the container's rundir
+	runDirHosts, err := c.copyHostFileToRundir("/etc/hosts")
+	if err != nil {
+		return errors.Wrapf(err, "unable to copy /etc/hosts to ", runDirHosts)
+	}
+
+	// Save OCI spec to disk
+	g := generate.NewFromSpec(c.config.Spec)
+	// If network namespace was requested, add it now
+	if c.config.CreateNetNS {
+		g.AddOrReplaceLinuxNamespace(spec.NetworkNamespace, c.state.NetNS.Path())
+	}
+	// Remove default /etc/shm mount
+	g.RemoveMount("/dev/shm")
+	// Mount ShmDir from host into container
+	shmMnt := spec.Mount{
+		Type:        "bind",
+		Source:      c.config.ShmDir,
+		Destination: "/dev/shm",
+		Options:     []string{"rw", "bind"},
+	}
+	g.AddMount(shmMnt)
+	// Bind mount resolv.conf
+	resolvMnt := spec.Mount{
+		Type:        "bind",
+		Source:      runDirResolv,
+		Destination: "/etc/resolv.conf",
+		Options:     []string{"rw", "bind"},
+	}
+	g.AddMount(resolvMnt)
+	// Bind mount hosts
+	hostsMnt := spec.Mount{
+		Type:        "bind",
+		Source:      runDirHosts,
+		Destination: "/etc/hosts",
+		Options:     []string{"rw", "bind"},
+	}
+	g.AddMount(hostsMnt)
+
+	if c.config.User != "" {
+		if !c.state.Mounted {
+			return errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate User field", c.ID())
+		}
+		uid, gid, err := chrootuser.GetUser(c.state.Mountpoint, c.config.User)
+		if err != nil {
+			return err
+		}
+		// User and Group must go together
+		g.SetProcessUID(uid)
+		g.SetProcessGID(gid)
+	}
+
+	// Add shared namespaces from other containers
+	if c.config.IPCNsCtr != "" {
+		ipcCtr, err := c.runtime.state.Container(c.config.IPCNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := ipcCtr.NamespacePath(IPCNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.IPCNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.MountNsCtr != "" {
+		mountCtr, err := c.runtime.state.Container(c.config.MountNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := mountCtr.NamespacePath(MountNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.MountNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.NetNsCtr != "" {
+		netCtr, err := c.runtime.state.Container(c.config.NetNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := netCtr.NamespacePath(NetNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.NetworkNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.PIDNsCtr != "" {
+		pidCtr, err := c.runtime.state.Container(c.config.PIDNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := pidCtr.NamespacePath(PIDNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(string(spec.PIDNamespace), nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.UserNsCtr != "" {
+		userCtr, err := c.runtime.state.Container(c.config.UserNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := userCtr.NamespacePath(UserNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.UserNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.UTSNsCtr != "" {
+		utsCtr, err := c.runtime.state.Container(c.config.UTSNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := utsCtr.NamespacePath(UTSNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.UTSNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+	if c.config.CgroupNsCtr != "" {
+		cgroupCtr, err := c.runtime.state.Container(c.config.CgroupNsCtr)
+		if err != nil {
+			return err
+		}
+
+		nsPath, err := cgroupCtr.NamespacePath(CgroupNS)
+		if err != nil {
+			return err
+		}
+
+		if err := g.AddOrReplaceLinuxNamespace(spec.CgroupNamespace, nsPath); err != nil {
+			return err
+		}
+	}
+
+	c.runningSpec = g.Spec()
+	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)
+
+	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())
+	}
+
+	logrus.Debugf("Created OCI spec for container %s at %s", c.ID(), jsonPath)
+
+	c.state.ConfigPath = jsonPath
+
+	// With the spec complete, do an OCI create
+	// TODO set cgroup parent in a sane fashion
+	if err := c.runtime.ociRuntime.createContainer(c, CgroupParent); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Created container %s in runc", c.ID())
+
+	c.state.State = ContainerStateCreated
+
+	return c.save()
+}
+
+// Start starts a container
+func (c *Container) Start() error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	// 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())
+	}
+
+	// Mount storage for the container
+	if err := c.mountStorage(); err != nil {
+		return err
+	}
+
+	if err := c.runtime.ociRuntime.startContainer(c); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Started container %s", c.ID())
+
+	c.state.State = ContainerStateRunning
+
+	return c.save()
+}
+
+// Stop uses the container's stop signal (or SIGTERM if no signal was specified)
+// to stop the container, and if it has not stopped after the given timeout (in
+// seconds), uses SIGKILL to attempt to forcibly stop the container.
+// If timeout is 0, SIGKILL will be used immediately
+func (c *Container) Stop(timeout uint) error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	logrus.Debugf("Stopping ctr %s with timeout %d", c.ID(), timeout)
+
+	if c.state.State == ContainerStateConfigured ||
+		c.state.State == ContainerStateUnknown ||
+		c.state.State == ContainerStatePaused {
+		return errors.Wrapf(ErrCtrStateInvalid, "can only stop created, running, or stopped containers")
+	}
+
+	if err := c.runtime.ociRuntime.stopContainer(c, timeout); err != nil {
+		return err
+	}
+
+	// Sync the container's state to pick up return code
+	if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil {
+		return err
+	}
+
+	return c.cleanupStorage()
+}
+
+// Kill sends a signal to a container
+func (c *Container) Kill(signal uint) error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	if c.state.State != ContainerStateRunning {
+		return errors.Wrapf(ErrCtrStateInvalid, "can only kill running containers")
+	}
+
+	return c.runtime.ociRuntime.killContainer(c, signal)
+}
+
+// Exec starts a new process inside the container
+func (c *Container) Exec(tty, privileged bool, env, cmd []string, user string) error {
+	var capList []string
+
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	conState := c.state.State
+
+	if conState != ContainerStateRunning {
+		return errors.Errorf("cannot attach to container that is not running")
+	}
+	if privileged {
+		capList = caps.GetAllCapabilities()
+	}
+	globalOpts := runcGlobalOptions{
+		log: c.LogPath(),
+	}
+	execOpts := runcExecOptions{
+		capAdd:  capList,
+		pidFile: filepath.Join(c.state.RunDir, fmt.Sprintf("%s-execpid", stringid.GenerateNonCryptoID()[:12])),
+		env:     env,
+		user:    user,
+		cwd:     c.config.Spec.Process.Cwd,
+		tty:     tty,
+	}
+
+	return c.runtime.ociRuntime.execContainer(c, cmd, globalOpts, execOpts)
+}
+
+// Attach attaches to a container
+// Returns fully qualified URL of streaming server for the container
+func (c *Container) Attach(noStdin bool, keys string, attached chan<- bool) error {
+	if !c.locked {
+		c.lock.Lock()
+		if err := c.syncContainer(); err != nil {
+			c.lock.Unlock()
+			return err
+		}
+		c.lock.Unlock()
+	}
+
+	if c.state.State != ContainerStateCreated &&
+		c.state.State != ContainerStateRunning {
+		return errors.Wrapf(ErrCtrStateInvalid, "can only attach to created or running containers")
+	}
+
+	// Check the validity of the provided keys first
+	var err error
+	detachKeys := []byte{}
+	if len(keys) > 0 {
+		detachKeys, err = term.ToBytes(keys)
+		if err != nil {
+			return errors.Wrapf(err, "invalid detach keys")
+		}
+	}
+
+	resize := make(chan remotecommand.TerminalSize)
+	defer close(resize)
+
+	err = c.attachContainerSocket(resize, noStdin, detachKeys, attached)
+	return err
+}
+
+// Mount mounts a container's filesystem on the host
+// The path where the container has been mounted is returned
+func (c *Container) Mount(label string) (string, error) {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return "", err
+		}
+	}
+
+	// return mountpoint if container already mounted
+	if c.state.Mounted {
+		return c.state.Mountpoint, nil
+	}
+
+	mountLabel := label
+	if label == "" {
+		mountLabel = c.config.MountLabel
+	}
+	mountPoint, err := c.runtime.store.Mount(c.ID(), mountLabel)
+	if err != nil {
+		return "", err
+	}
+	c.state.Mountpoint = mountPoint
+	c.state.Mounted = true
+	c.config.MountLabel = mountLabel
+
+	if err := c.save(); err != nil {
+		return "", err
+	}
+
+	return mountPoint, nil
+}
+
+// Unmount unmounts a container's filesystem on the host
+func (c *Container) Unmount() error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	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())
+	}
+
+	return c.cleanupStorage()
+}
+
+// Pause pauses a container
+func (c *Container) Pause() error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	if c.state.State == ContainerStatePaused {
+		return errors.Wrapf(ErrCtrStateInvalid, "%q is already paused", c.ID())
+	}
+	if c.state.State != ContainerStateRunning && c.state.State != ContainerStateCreated {
+		return errors.Wrapf(ErrCtrStateInvalid, "%q is not running/created, can't pause", c.state.State)
+	}
+	if err := c.runtime.ociRuntime.pauseContainer(c); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Paused container %s", c.ID())
+
+	c.state.State = ContainerStatePaused
+
+	return c.save()
+}
+
+// Unpause unpauses a container
+func (c *Container) Unpause() error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	if c.state.State != ContainerStatePaused {
+		return errors.Wrapf(ErrCtrStateInvalid, "%q is not paused, can't unpause", c.ID())
+	}
+	if err := c.runtime.ociRuntime.unpauseContainer(c); err != nil {
+		return err
+	}
+
+	logrus.Debugf("Unpaused container %s", c.ID())
+
+	c.state.State = ContainerStateRunning
+
+	return c.save()
+}
+
+// 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 {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	return c.export(path)
+}
+
+// AddArtifact creates and writes to an artifact file for the container
+func (c *Container) AddArtifact(name string, data []byte) error {
+	if !c.valid {
+		return ErrCtrRemoved
+	}
+
+	return ioutil.WriteFile(c.getArtifactPath(name), data, 0740)
+}
+
+// GetArtifact reads the specified artifact file from the container
+func (c *Container) GetArtifact(name string) ([]byte, error) {
+	if !c.valid {
+		return nil, ErrCtrRemoved
+	}
+
+	return ioutil.ReadFile(c.getArtifactPath(name))
+}
+
+// RemoveArtifact deletes the specified artifacts file
+func (c *Container) RemoveArtifact(name string) error {
+	if !c.valid {
+		return ErrCtrRemoved
+	}
+
+	return os.Remove(c.getArtifactPath(name))
+}
+
+// Inspect a container for low-level information
+func (c *Container) Inspect(size bool) (*ContainerInspectData, error) {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return nil, err
+		}
+	}
+
+	storeCtr, err := c.runtime.store.Container(c.ID())
+	if err != nil {
+		return nil, errors.Wrapf(err, "error getting container from store %q", c.ID())
+	}
+	layer, err := c.runtime.store.Layer(storeCtr.LayerID)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error reading information about layer %q", storeCtr.LayerID)
+	}
+	driverData, err := driver.GetDriverData(c.runtime.store, layer.ID)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error getting graph driver info %q", c.ID())
+	}
+
+	return c.getContainerInspectData(size, driverData)
+}
+
+// Commit commits the changes between a container and its image, creating a new
+// image
+func (c *Container) Commit(pause bool, options CopyOptions) error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+
+	if c.state.State == ContainerStateRunning && pause {
+		if err := c.runtime.ociRuntime.pauseContainer(c); err != nil {
+			return errors.Wrapf(err, "error pausing container %q", c.ID())
+		}
+		defer func() {
+			if err := c.runtime.ociRuntime.unpauseContainer(c); err != nil {
+				logrus.Errorf("error unpausing container %q: %v", c.ID(), err)
+			}
+		}()
+	}
+
+	tempFile, err := ioutil.TempFile(c.runtime.config.TmpDir, "podman-commit")
+	if err != nil {
+		return errors.Wrapf(err, "error creating temp file")
+	}
+	defer os.Remove(tempFile.Name())
+	defer tempFile.Close()
+
+	if err := c.export(tempFile.Name()); err != nil {
+		return err
+	}
+	return c.runtime.ImportImage(tempFile.Name(), options)
+}
+
+// Wait blocks on a container to exit and returns its exit code
+func (c *Container) Wait() (int32, error) {
+	if !c.valid {
+		return -1, ErrCtrRemoved
+	}
+
+	err := wait.PollImmediateInfinite(1,
+		func() (bool, error) {
+			stopped, err := c.isStopped()
+			if err != nil {
+				return false, err
+			}
+			if !stopped {
+				return false, nil
+			} else { // nolint
+				return true, nil // nolint
+			} // nolint
+		},
+	)
+	if err != nil {
+		return 0, err
+	}
+	exitCode := c.state.ExitCode
+	return exitCode, nil
+}
+
+// CleanupStorage unmounts all mount points in container and cleans up container storage
+func (c *Container) CleanupStorage() error {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+		if err := c.syncContainer(); err != nil {
+			return err
+		}
+	}
+	return c.cleanupStorage()
+}
+
+// Batch starts a batch operation on the given container
+// All commands in the passed function will execute under the same lock and
+// without syncronyzing state after each operation
+// This will result in substantial performance benefits when running numerous
+// commands on the same container
+// Note that the container passed into the Batch function cannot be removed
+// during batched operations. runtime.RemoveContainer can only be called outside
+// of Batch
+// Any error returned by the given batch function will be returned unmodified by
+// Batch
+// As Batch normally disables updating the current state of the container, the
+// Sync() function is provided to enable container state to be updated and
+// checked within Batch.
+func (c *Container) Batch(batchFunc func(*Container) error) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if err := c.syncContainer(); err != nil {
+		return err
+	}
+
+	newCtr := new(Container)
+	newCtr.config = c.config
+	newCtr.state = c.state
+	newCtr.runtime = c.runtime
+	newCtr.lock = c.lock
+	newCtr.valid = true
+
+	newCtr.locked = true
+
+	if err := batchFunc(newCtr); err != nil {
+		return err
+	}
+
+	newCtr.locked = false
+
+	return c.save()
+}
+
+// Sync updates the current state of the container, checking whether its state
+// has changed
+// Sync can only be used inside Batch() - otherwise, it will be done
+// automatically.
+// When called outside Batch(), Sync() is a no-op
+func (c *Container) Sync() error {
+	if !c.locked {
+		return nil
+	}
+
+	// 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
+			}
+		}
+	}
+
+	return nil
+}