func (container *Container) setupContainerDns() error {
if container.ResolvConfPath != "" {
return nil
}
var (
config = container.hostConfig
runtime = container.runtime
)
resolvConf, err := utils.GetResolvConf()
if err != nil {
return err
}
// If custom dns exists, then create a resolv.conf for the container
if len(config.Dns) > 0 || len(runtime.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(runtime.config.DnsSearch) > 0 {
var (
dns = utils.GetNameservers(resolvConf)
dnsSearch = utils.GetSearchDomains(resolvConf)
)
if len(config.Dns) > 0 {
dns = config.Dns
} else if len(runtime.config.Dns) > 0 {
dns = runtime.config.Dns
}
if len(config.DnsSearch) > 0 {
dnsSearch = config.DnsSearch
} else if len(runtime.config.DnsSearch) > 0 {
dnsSearch = runtime.config.DnsSearch
}
container.ResolvConfPath = path.Join(container.root, "resolv.conf")
f, err := os.Create(container.ResolvConfPath)
if err != nil {
return err
}
defer f.Close()
for _, dns := range dns {
if _, err := f.Write([]byte("nameserver " + dns + "\n")); err != nil {
return err
}
}
if len(dnsSearch) > 0 {
if _, err := f.Write([]byte("search " + strings.Join(dnsSearch, " ") + "\n")); err != nil {
return err
}
}
} else {
container.ResolvConfPath = "/etc/resolv.conf"
}
return nil
}
// Create creates a new container from the given configuration with a given name.
func (runtime *Runtime) Create(config *runconfig.Config, name string) (*Container, []string, error) {
// Lookup image
img, err := runtime.repositories.LookupImage(config.Image)
if err != nil {
return nil, nil, err
}
// We add 2 layers to the depth because the container's rw and
// init layer add to the restriction
depth, err := img.Depth()
if err != nil {
return nil, nil, err
}
if depth+2 >= MaxImageDepth {
return nil, nil, fmt.Errorf("Cannot create container with more than %d parents", MaxImageDepth)
}
checkDeprecatedExpose := func(config *runconfig.Config) bool {
if config != nil {
if config.PortSpecs != nil {
for _, p := range config.PortSpecs {
if strings.Contains(p, ":") {
return true
}
}
}
}
return false
}
warnings := []string{}
if checkDeprecatedExpose(img.Config) || checkDeprecatedExpose(config) {
warnings = append(warnings, "The mapping to public ports on your host via Dockerfile EXPOSE (host:port:port) has been deprecated. Use -p to publish the ports.")
}
if img.Config != nil {
if err := runconfig.Merge(config, img.Config); err != nil {
return nil, nil, err
}
}
if len(config.Entrypoint) == 0 && len(config.Cmd) == 0 {
return nil, nil, fmt.Errorf("No command specified")
}
// Generate id
id := utils.GenerateRandomID()
if name == "" {
name, err = generateRandomName(runtime)
if err != nil {
name = utils.TruncateID(id)
}
} else {
if !validContainerNamePattern.MatchString(name) {
return nil, nil, fmt.Errorf("Invalid container name (%s), only %s are allowed", name, validContainerNameChars)
}
}
if name[0] != '/' {
name = "/" + name
}
// Set the enitity in the graph using the default name specified
if _, err := runtime.containerGraph.Set(name, id); err != nil {
if !graphdb.IsNonUniqueNameError(err) {
return nil, nil, err
}
conflictingContainer, err := runtime.GetByName(name)
if err != nil {
if strings.Contains(err.Error(), "Could not find entity") {
return nil, nil, err
}
// Remove name and continue starting the container
if err := runtime.containerGraph.Delete(name); err != nil {
return nil, nil, err
}
} else {
nameAsKnownByUser := strings.TrimPrefix(name, "/")
return nil, nil, fmt.Errorf(
"Conflict, The name %s is already assigned to %s. You have to delete (or rename) that container to be able to assign %s to a container again.", nameAsKnownByUser,
utils.TruncateID(conflictingContainer.ID), nameAsKnownByUser)
}
}
// Generate default hostname
// FIXME: the lxc template no longer needs to set a default hostname
if config.Hostname == "" {
config.Hostname = id[:12]
}
var args []string
var entrypoint string
if len(config.Entrypoint) != 0 {
entrypoint = config.Entrypoint[0]
args = append(config.Entrypoint[1:], config.Cmd...)
} else {
entrypoint = config.Cmd[0]
args = config.Cmd[1:]
}
container := &Container{
// FIXME: we should generate the ID here instead of receiving it as an argument
ID: id,
Created: time.Now().UTC(),
Path: entrypoint,
Args: args, //FIXME: de-duplicate from config
Config: config,
hostConfig: &runconfig.HostConfig{},
Image: img.ID, // Always use the resolved image id
NetworkSettings: &NetworkSettings{},
Name: name,
Driver: runtime.driver.String(),
ExecDriver: runtime.execDriver.Name(),
}
container.root = runtime.containerRoot(container.ID)
// Step 1: create the container directory.
// This doubles as a barrier to avoid race conditions.
if err := os.Mkdir(container.root, 0700); err != nil {
return nil, nil, err
}
initID := fmt.Sprintf("%s-init", container.ID)
if err := runtime.driver.Create(initID, img.ID, config.Context["mount_label"]); err != nil {
return nil, nil, err
}
initPath, err := runtime.driver.Get(initID)
if err != nil {
return nil, nil, err
}
defer runtime.driver.Put(initID)
if err := graph.SetupInitLayer(initPath); err != nil {
return nil, nil, err
}
if err := runtime.driver.Create(container.ID, initID, config.Context["mount_label"]); err != nil {
return nil, nil, err
}
resolvConf, err := utils.GetResolvConf()
if err != nil {
return nil, nil, err
}
if len(config.Dns) == 0 && len(runtime.config.Dns) == 0 && utils.CheckLocalDns(resolvConf) {
runtime.config.Dns = DefaultDns
}
// If custom dns exists, then create a resolv.conf for the container
if len(config.Dns) > 0 || len(runtime.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(runtime.config.DnsSearch) > 0 {
dns := utils.GetNameservers(resolvConf)
dnsSearch := utils.GetSearchDomains(resolvConf)
if len(config.Dns) > 0 {
dns = config.Dns
} else if len(runtime.config.Dns) > 0 {
dns = runtime.config.Dns
}
if len(config.DnsSearch) > 0 {
dnsSearch = config.DnsSearch
} else if len(runtime.config.DnsSearch) > 0 {
dnsSearch = runtime.config.DnsSearch
}
container.ResolvConfPath = path.Join(container.root, "resolv.conf")
f, err := os.Create(container.ResolvConfPath)
if err != nil {
return nil, nil, err
}
defer f.Close()
for _, dns := range dns {
if _, err := f.Write([]byte("nameserver " + dns + "\n")); err != nil {
return nil, nil, err
}
}
if len(dnsSearch) > 0 {
if _, err := f.Write([]byte("search " + strings.Join(dnsSearch, " ") + "\n")); err != nil {
return nil, nil, err
}
}
} else {
container.ResolvConfPath = "/etc/resolv.conf"
}
// Step 2: save the container json
if err := container.ToDisk(); err != nil {
return nil, nil, err
}
// Step 3: register the container
if err := runtime.Register(container); err != nil {
return nil, nil, err
}
return container, warnings, nil
}