daemon/container.go
package daemon // import "github.com/docker/docker/daemon"
import (
"context"
"fmt"
"os"
"path/filepath"
"runtime"
"time"
"github.com/containerd/log"
containertypes "github.com/docker/docker/api/types/container"
networktypes "github.com/docker/docker/api/types/network"
"github.com/docker/docker/api/types/strslice"
"github.com/docker/docker/container"
"github.com/docker/docker/daemon/config"
"github.com/docker/docker/daemon/network"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/image"
"github.com/docker/docker/oci/caps"
"github.com/docker/docker/opts"
"github.com/docker/docker/pkg/system"
volumemounts "github.com/docker/docker/volume/mounts"
"github.com/docker/go-connections/nat"
"github.com/moby/sys/signal"
"github.com/opencontainers/selinux/go-selinux"
"github.com/pkg/errors"
)
// 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.WithStack(invalidIdentifier(prefixOrName))
}
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, err := daemon.containersReplica.GetByPrefix(prefixOrName)
if err != nil {
return nil, err
}
ctr := daemon.containers.Get(containerID)
if ctr == nil {
// Updates to the daemon.containersReplica ViewDB are not atomic
// or consistent w.r.t. the live daemon.containers Store so
// while reaching this code path may be indicative of a bug,
// it is not _necessarily_ the case.
log.G(context.TODO()).WithField("prefixOrName", prefixOrName).
WithField("id", containerID).
Debugf("daemon.GetContainer: container is known to daemon.containersReplica but not daemon.containers")
return nil, containerNotFound(prefixOrName)
}
return ctr, 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) {
ctr := daemon.newBaseContainer(id)
if err := ctr.FromDisk(); err != nil {
return nil, err
}
selinux.ReserveLabel(ctr.ProcessLabel)
if ctr.ID != id {
return ctr, fmt.Errorf("Container %s is stored at %s", ctr.ID, id)
}
return ctr, 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()
}
// once in the memory store it is visible to other goroutines
// grab a Lock until it has been checkpointed to avoid races
c.Lock()
defer c.Unlock()
daemon.containers.Add(c.ID, c)
return c.CheckpointTo(context.TODO(), daemon.containersReplica)
}
func (daemon *Daemon) newContainer(name string, operatingSystem string, config *containertypes.Config, hostConfig *containertypes.HostConfig, imgID image.ID, managed bool) (*container.Container, error) {
var (
id string
err error
)
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, errdefs.System(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{}
base.Name = name
base.Driver = daemon.imageService.StorageDriver()
base.OS = operatingSystem
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.containersReplica.Snapshot().GetID(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(cfg *config.Config, container *container.Container, hostConfig *containertypes.HostConfig) error {
container.Lock()
defer container.Unlock()
return daemon.parseSecurityOpt(cfg, &container.SecurityOptions, hostConfig)
}
func (daemon *Daemon) setHostConfig(container *container.Container, hostConfig *containertypes.HostConfig, defaultReadOnlyNonRecursive bool) 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, defaultReadOnlyNonRecursive); 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
}
if hostConfig != nil && hostConfig.NetworkMode == "" {
hostConfig.NetworkMode = networktypes.NetworkDefault
}
container.HostConfig = hostConfig
return nil
}
// verifyContainerSettings performs validation of the hostconfig and config
// structures.
func (daemon *Daemon) verifyContainerSettings(daemonCfg *configStore, hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) (warnings []string, err error) {
// First perform verification of settings common across all platforms.
if err = validateContainerConfig(config); err != nil {
return warnings, err
}
if err := validateHostConfig(hostConfig); err != nil {
return warnings, err
}
// Now do platform-specific verification
warnings, err = verifyPlatformContainerSettings(daemon, daemonCfg, hostConfig, update)
for _, w := range warnings {
log.G(context.TODO()).Warn(w)
}
return warnings, err
}
func validateContainerConfig(config *containertypes.Config) error {
if config == nil {
return nil
}
if err := translateWorkingDir(config); err != nil {
return err
}
if len(config.StopSignal) > 0 {
if _, err := signal.ParseSignal(config.StopSignal); err != nil {
return 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 err
}
}
return validateHealthCheck(config.Healthcheck)
}
func validateHostConfig(hostConfig *containertypes.HostConfig) error {
if hostConfig == nil {
return nil
}
if hostConfig.AutoRemove && !hostConfig.RestartPolicy.IsNone() {
return errors.Errorf("can't create 'AutoRemove' container with restart policy")
}
// Validate mounts; check if host directories still exist
parser := volumemounts.NewParser()
for _, c := range hostConfig.Mounts {
cfg := c
if err := parser.ValidateMountConfig(&cfg); err != nil {
return err
}
}
for _, extraHost := range hostConfig.ExtraHosts {
if _, err := opts.ValidateExtraHost(extraHost); err != nil {
return err
}
}
if err := validatePortBindings(hostConfig.PortBindings); err != nil {
return err
}
if err := containertypes.ValidateRestartPolicy(hostConfig.RestartPolicy); err != nil {
return err
}
if err := validateCapabilities(hostConfig); err != nil {
return err
}
if !hostConfig.Isolation.IsValid() {
return errors.Errorf("invalid isolation '%s' on %s", hostConfig.Isolation, runtime.GOOS)
}
for k := range hostConfig.Annotations {
if k == "" {
return errors.Errorf("invalid Annotations: the empty string is not permitted as an annotation key")
}
}
return nil
}
func validateCapabilities(hostConfig *containertypes.HostConfig) error {
if _, err := caps.NormalizeLegacyCapabilities(hostConfig.CapAdd); err != nil {
return errors.Wrap(err, "invalid CapAdd")
}
if _, err := caps.NormalizeLegacyCapabilities(hostConfig.CapDrop); err != nil {
return errors.Wrap(err, "invalid CapDrop")
}
// TODO consider returning warnings if "Privileged" is combined with Capabilities, CapAdd and/or CapDrop
return nil
}
// validateHealthCheck validates the healthcheck params of Config
func validateHealthCheck(healthConfig *containertypes.HealthConfig) error {
if healthConfig == nil {
return nil
}
if healthConfig.Interval != 0 && healthConfig.Interval < containertypes.MinimumDuration {
return errors.Errorf("Interval in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
}
if healthConfig.Timeout != 0 && healthConfig.Timeout < containertypes.MinimumDuration {
return errors.Errorf("Timeout in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
}
if healthConfig.Retries < 0 {
return errors.Errorf("Retries in Healthcheck cannot be negative")
}
if healthConfig.StartPeriod != 0 && healthConfig.StartPeriod < containertypes.MinimumDuration {
return errors.Errorf("StartPeriod in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
}
if healthConfig.StartInterval != 0 && healthConfig.StartInterval < containertypes.MinimumDuration {
return errors.Errorf("StartInterval in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
}
return nil
}
func validatePortBindings(ports nat.PortMap) error {
for port := range ports {
_, portStr := nat.SplitProtoPort(string(port))
if _, err := nat.ParsePort(portStr); err != nil {
return errors.Errorf("invalid port specification: %q", portStr)
}
for _, pb := range ports[port] {
_, err := nat.NewPort(nat.SplitProtoPort(pb.HostPort))
if err != nil {
return errors.Errorf("invalid port specification: %q", pb.HostPort)
}
}
}
return nil
}
// translateWorkingDir translates the working-dir for the target platform,
// and returns an error if the given path is not an absolute path.
func translateWorkingDir(config *containertypes.Config) error {
if config.WorkingDir == "" {
return nil
}
wd := filepath.FromSlash(config.WorkingDir) // Ensure in platform semantics
if !system.IsAbs(wd) {
return fmt.Errorf("the working directory '%s' is invalid, it needs to be an absolute path", config.WorkingDir)
}
config.WorkingDir = filepath.Clean(wd)
return nil
}