func (container *Container) setupLinkedContainers() ([]string, error) {
var (
env []string
runtime = container.runtime
)
children, err := runtime.Children(container.Name)
if err != nil {
return nil, err
}
if len(children) > 0 {
container.activeLinks = make(map[string]*links.Link, len(children))
// If we encounter an error make sure that we rollback any network
// config and ip table changes
rollback := func() {
for _, link := range container.activeLinks {
link.Disable()
}
container.activeLinks = nil
}
for linkAlias, child := range children {
if !child.State.IsRunning() {
return nil, fmt.Errorf("Cannot link to a non running container: %s AS %s", child.Name, linkAlias)
}
link, err := links.NewLink(
container.NetworkSettings.IPAddress,
child.NetworkSettings.IPAddress,
linkAlias,
child.Config.Env,
child.Config.ExposedPorts,
runtime.eng)
if err != nil {
rollback()
return nil, err
}
container.activeLinks[link.Alias()] = link
if err := link.Enable(); err != nil {
rollback()
return nil, err
}
for _, envVar := range link.ToEnv() {
env = append(env, envVar)
}
}
}
return env, nil
}
func (container *Container) Start() (err error) {
container.Lock()
defer container.Unlock()
if container.State.IsRunning() {
return fmt.Errorf("The container %s is already running.", container.ID)
}
defer func() {
if err != nil {
container.cleanup()
}
}()
if err := container.Mount(); err != nil {
return err
}
if container.runtime.config.DisableNetwork {
container.Config.NetworkDisabled = true
container.buildHostnameAndHostsFiles("127.0.1.1")
} else {
if err := container.allocateNetwork(); err != nil {
return err
}
container.buildHostnameAndHostsFiles(container.NetworkSettings.IPAddress)
}
// Make sure the config is compatible with the current kernel
if container.Config.Memory > 0 && !container.runtime.sysInfo.MemoryLimit {
log.Printf("WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.\n")
container.Config.Memory = 0
}
if container.Config.Memory > 0 && !container.runtime.sysInfo.SwapLimit {
log.Printf("WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.\n")
container.Config.MemorySwap = -1
}
if container.runtime.sysInfo.IPv4ForwardingDisabled {
log.Printf("WARNING: IPv4 forwarding is disabled. Networking will not work")
}
if err := prepareVolumesForContainer(container); err != nil {
return err
}
// Setup environment
env := []string{
"HOME=/",
"PATH=" + DefaultPathEnv,
"HOSTNAME=" + container.Config.Hostname,
}
if container.Config.Tty {
env = append(env, "TERM=xterm")
}
// Init any links between the parent and children
runtime := container.runtime
children, err := runtime.Children(container.Name)
if err != nil {
return err
}
if len(children) > 0 {
container.activeLinks = make(map[string]*links.Link, len(children))
// If we encounter an error make sure that we rollback any network
// config and ip table changes
rollback := func() {
for _, link := range container.activeLinks {
link.Disable()
}
container.activeLinks = nil
}
for linkAlias, child := range children {
if !child.State.IsRunning() {
return fmt.Errorf("Cannot link to a non running container: %s AS %s", child.Name, linkAlias)
}
link, err := links.NewLink(
container.NetworkSettings.IPAddress,
child.NetworkSettings.IPAddress,
linkAlias,
child.Config.Env,
child.Config.ExposedPorts,
runtime.eng)
if err != nil {
rollback()
return err
}
container.activeLinks[link.Alias()] = link
if err := link.Enable(); err != nil {
rollback()
return err
}
for _, envVar := range link.ToEnv() {
env = append(env, envVar)
}
}
}
// because the env on the container can override certain default values
// we need to replace the 'env' keys where they match and append anything
// else.
env = utils.ReplaceOrAppendEnvValues(env, container.Config.Env)
if err := container.generateEnvConfig(env); err != nil {
return err
}
if container.Config.WorkingDir != "" {
container.Config.WorkingDir = path.Clean(container.Config.WorkingDir)
pthInfo, err := os.Stat(path.Join(container.basefs, container.Config.WorkingDir))
if err != nil {
if !os.IsNotExist(err) {
return err
}
if err := os.MkdirAll(path.Join(container.basefs, container.Config.WorkingDir), 0755); err != nil {
return err
}
}
if pthInfo != nil && !pthInfo.IsDir() {
return fmt.Errorf("Cannot mkdir: %s is not a directory", container.Config.WorkingDir)
}
}
envPath, err := container.EnvConfigPath()
if err != nil {
return err
}
populateCommand(container)
container.command.Env = env
if err := setupMountsForContainer(container, envPath); err != nil {
return err
}
// Setup logging of stdout and stderr to disk
if err := container.runtime.LogToDisk(container.stdout, container.logPath("json"), "stdout"); err != nil {
return err
}
if err := container.runtime.LogToDisk(container.stderr, container.logPath("json"), "stderr"); err != nil {
return err
}
container.waitLock = make(chan struct{})
callbackLock := make(chan struct{})
callback := func(command *execdriver.Command) {
container.State.SetRunning(command.Pid())
if command.Tty {
// The callback is called after the process Start()
// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlace
// which we close here.
if c, ok := command.Stdout.(io.Closer); ok {
c.Close()
}
}
if err := container.ToDisk(); err != nil {
utils.Debugf("%s", err)
}
close(callbackLock)
}
// We use a callback here instead of a goroutine and an chan for
// syncronization purposes
cErr := utils.Go(func() error { return container.monitor(callback) })
// Start should not return until the process is actually running
select {
case <-callbackLock:
case err := <-cErr:
return err
}
return nil
}