moby/daemon/container.go

package daemon

import (
	"fmt"
	"path/filepath"
	"time"

	"github.com/docker/docker/container"
	"github.com/docker/docker/daemon/network"
	"github.com/docker/docker/errors"
	"github.com/docker/docker/image"
	"github.com/docker/docker/pkg/truncindex"
	containertypes "github.com/docker/engine-api/types/container"
)

// GetContainer looks for a container using the provided information, which could be
// one of the following inputs from the caller:
//  - A full container ID, which will exact match a container in daemon's list
//  - A container name, which will only exact match via the GetByName() function
//  - A partial container ID prefix (e.g. short ID) of any length that is
//    unique enough to only return a single container object
//  If none of these searches succeed, an error is returned
func (daemon *Daemon) GetContainer(prefixOrName string) (*container.Container, error) {
	if len(prefixOrName) == 0 {
		return nil, errors.NewBadRequestError(fmt.Errorf("No container name or ID supplied"))
	}

	if containerByID := daemon.containers.Get(prefixOrName); containerByID != nil {
		// prefix is an exact match to a full container ID
		return containerByID, nil
	}

	// GetByName will match only an exact name provided; we ignore errors
	if containerByName, _ := daemon.GetByName(prefixOrName); containerByName != nil {
		// prefix is an exact match to a full container Name
		return containerByName, nil
	}

	containerID, indexError := daemon.idIndex.Get(prefixOrName)
	if indexError != nil {
		// When truncindex defines an error type, use that instead
		if indexError == truncindex.ErrNotExist {
			err := fmt.Errorf("No such container: %s", prefixOrName)
			return nil, errors.NewRequestNotFoundError(err)
		}
		return nil, indexError
	}
	return daemon.containers.Get(containerID), nil
}

// Exists returns a true if a container of the specified ID or name exists,
// false otherwise.
func (daemon *Daemon) Exists(id string) bool {
	c, _ := daemon.GetContainer(id)
	return c != nil
}

// IsPaused returns a bool indicating if the specified container is paused.
func (daemon *Daemon) IsPaused(id string) bool {
	c, _ := daemon.GetContainer(id)
	return c.State.IsPaused()
}

func (daemon *Daemon) containerRoot(id string) string {
	return filepath.Join(daemon.repository, id)
}

// Load reads the contents of a container from disk
// This is typically done at startup.
func (daemon *Daemon) load(id string) (*container.Container, error) {
	container := daemon.newBaseContainer(id)

	if err := container.FromDisk(); err != nil {
		return nil, err
	}

	if container.ID != id {
		return container, fmt.Errorf("Container %s is stored at %s", container.ID, id)
	}

	return container, nil
}

// Register makes a container object usable by the daemon as <container.ID>
func (daemon *Daemon) Register(c *container.Container) error {
	// Attach to stdout and stderr
	if c.Config.OpenStdin {
		c.NewInputPipes()
	} else {
		c.NewNopInputPipe()
	}

	daemon.containers.Add(c.ID, c)
	daemon.idIndex.Add(c.ID)

	return nil
}

func (daemon *Daemon) newContainer(name string, config *containertypes.Config, imgID image.ID) (*container.Container, error) {
	var (
		id             string
		err            error
		noExplicitName = name == ""
	)
	id, name, err = daemon.generateIDAndName(name)
	if err != nil {
		return nil, err
	}

	daemon.generateHostname(id, config)
	entrypoint, args := daemon.getEntrypointAndArgs(config.Entrypoint, config.Cmd)

	base := daemon.newBaseContainer(id)
	base.Created = time.Now().UTC()
	base.Path = entrypoint
	base.Args = args //FIXME: de-duplicate from config
	base.Config = config
	base.HostConfig = &containertypes.HostConfig{}
	base.ImageID = imgID
	base.NetworkSettings = &network.Settings{IsAnonymousEndpoint: noExplicitName}
	base.Name = name
	base.Driver = daemon.GraphDriverName()

	return base, err
}

// GetByName returns a container given a name.
func (daemon *Daemon) GetByName(name string) (*container.Container, error) {
	if len(name) == 0 {
		return nil, fmt.Errorf("No container name supplied")
	}
	fullName := name
	if name[0] != '/' {
		fullName = "/" + name
	}
	id, err := daemon.nameIndex.Get(fullName)
	if err != nil {
		return nil, fmt.Errorf("Could not find entity for %s", name)
	}
	e := daemon.containers.Get(id)
	if e == nil {
		return nil, fmt.Errorf("Could not find container for entity id %s", id)
	}
	return e, nil
}