package daemon
 
 import (
 	"fmt"

 	"os"

 	"path/filepath"
 	"time"
 

 	"github.com/docker/docker/api/errors"

 	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/strslice"

 	"github.com/docker/docker/container"
 	"github.com/docker/docker/daemon/network"
 	"github.com/docker/docker/image"

 	"github.com/docker/docker/pkg/signal"
 	"github.com/docker/docker/pkg/system"

 	"github.com/docker/docker/pkg/truncindex"

 	"github.com/docker/docker/runconfig/opts"

 	"github.com/docker/go-connections/nat"

 )
 
 // 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.StreamConfig.NewInputPipes()

 	} else {

 		c.StreamConfig.NewNopInputPipe()

 	}
 
 	daemon.containers.Add(c.ID, c)
 	daemon.idIndex.Add(c.ID)
 
 	return nil
 }
 

 func (daemon *Daemon) newContainer(name string, config *containertypes.Config, hostConfig *containertypes.HostConfig, imgID image.ID, managed bool) (*container.Container, error) {

 	var (
 		id             string
 		err            error
 		noExplicitName = name == ""
 	)
 	id, name, err = daemon.generateIDAndName(name)
 	if err != nil {
 		return nil, err
 	}
 

 	if hostConfig.NetworkMode.IsHost() {
 		if config.Hostname == "" {
 			config.Hostname, err = os.Hostname()
 			if err != nil {
 				return nil, err
 			}
 		}
 	} else {
 		daemon.generateHostname(id, config)
 	}

 	entrypoint, args := daemon.getEntrypointAndArgs(config.Entrypoint, config.Cmd)
 
 	base := daemon.newBaseContainer(id)
 	base.Created = time.Now().UTC()

 	base.Managed = managed

 	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
 }

 
 // newBaseContainer creates a new container with its initial
 // configuration based on the root storage from the daemon.
 func (daemon *Daemon) newBaseContainer(id string) *container.Container {
 	return container.NewBaseContainer(id, daemon.containerRoot(id))
 }
 
 func (daemon *Daemon) getEntrypointAndArgs(configEntrypoint strslice.StrSlice, configCmd strslice.StrSlice) (string, []string) {
 	if len(configEntrypoint) != 0 {
 		return configEntrypoint[0], append(configEntrypoint[1:], configCmd...)
 	}
 	return configCmd[0], configCmd[1:]
 }
 
 func (daemon *Daemon) generateHostname(id string, config *containertypes.Config) {
 	// Generate default hostname
 	if config.Hostname == "" {
 		config.Hostname = id[:12]
 	}
 }
 
 func (daemon *Daemon) setSecurityOptions(container *container.Container, hostConfig *containertypes.HostConfig) error {
 	container.Lock()
 	defer container.Unlock()
 	return parseSecurityOpt(container, hostConfig)
 }
 
 func (daemon *Daemon) setHostConfig(container *container.Container, hostConfig *containertypes.HostConfig) error {
 	// Do not lock while creating volumes since this could be calling out to external plugins
 	// Don't want to block other actions, like `docker ps` because we're waiting on an external plugin
 	if err := daemon.registerMountPoints(container, hostConfig); err != nil {
 		return err
 	}
 
 	container.Lock()
 	defer container.Unlock()
 
 	// Register any links from the host config before starting the container
 	if err := daemon.registerLinks(container, hostConfig); err != nil {
 		return err
 	}
 
 	// make sure links is not nil
 	// this ensures that on the next daemon restart we don't try to migrate from legacy sqlite links
 	if hostConfig.Links == nil {
 		hostConfig.Links = []string{}
 	}
 
 	container.HostConfig = hostConfig
 	return container.ToDisk()
 }
 
 // verifyContainerSettings performs validation of the hostconfig and config
 // structures.

 func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {

 
 	// First perform verification of settings common across all platforms.
 	if config != nil {
 		if config.WorkingDir != "" {
 			config.WorkingDir = filepath.FromSlash(config.WorkingDir) // Ensure in platform semantics
 			if !system.IsAbs(config.WorkingDir) {

 				return nil, fmt.Errorf("the working directory '%s' is invalid, it needs to be an absolute path", config.WorkingDir)

 			}
 		}
 
 		if len(config.StopSignal) > 0 {
 			_, err := signal.ParseSignal(config.StopSignal)
 			if err != nil {
 				return nil, err
 			}
 		}
 

 		// Validate if Env contains empty variable or not (e.g., ``, `=foo`)
 		for _, env := range config.Env {
 			if _, err := opts.ValidateEnv(env); err != nil {
 				return nil, err
 			}
 		}

 	}
 
 	if hostConfig == nil {
 		return nil, nil
 	}
 

 	if hostConfig.AutoRemove && !hostConfig.RestartPolicy.IsNone() {

 		return nil, fmt.Errorf("can't create 'AutoRemove' container with restart policy")

 	}
 

 	for port := range hostConfig.PortBindings {
 		_, portStr := nat.SplitProtoPort(string(port))
 		if _, err := nat.ParsePort(portStr); err != nil {

 			return nil, fmt.Errorf("invalid port specification: %q", portStr)

 		}
 		for _, pb := range hostConfig.PortBindings[port] {
 			_, err := nat.NewPort(nat.SplitProtoPort(pb.HostPort))
 			if err != nil {

 				return nil, fmt.Errorf("invalid port specification: %q", pb.HostPort)

 			}
 		}
 	}
 

 	p := hostConfig.RestartPolicy
 
 	switch p.Name {
 	case "always", "unless-stopped", "no":
 		if p.MaximumRetryCount != 0 {

 			return nil, fmt.Errorf("maximum retry count cannot be used with restart policy '%s'", p.Name)

 		}
 	case "on-failure":

 		if p.MaximumRetryCount < 0 {
 			return nil, fmt.Errorf("maximum retry count cannot be negative")

 		}
 	case "":
 	// do nothing
 	default:
 		return nil, fmt.Errorf("invalid restart policy '%s'", p.Name)
 	}
 

 	// Now do platform-specific verification
 	return verifyPlatformContainerSettings(daemon, hostConfig, config, update)
 }