示例#1
0
// TODO(vmarmol): Deprecate over time as old Dockers are phased out.
func ReadConfig(dockerRoot, dockerRun, containerID string) (*configs.Config, error) {
	// Try using the new config if it is available.
	configPath := configPath(dockerRun, containerID)
	if utils.FileExists(configPath) {
		out, err := ioutil.ReadFile(configPath)
		if err != nil {
			return nil, err
		}

		var state libcontainer.State
		err = json.Unmarshal(out, &state)
		if err != nil {
			glog.Errorf("Unmarshal failure for: \n\n%v\n", string(out))
			return nil, err
		}
		return &state.Config, nil
	}

	// Fallback to reading the old config which is comprised of the state and config files.
	oldConfigPath := oldConfigPath(dockerRoot, containerID)
	out, err := ioutil.ReadFile(oldConfigPath)
	if err != nil {
		glog.Errorf("Unmarshal failure for: \n\n%v\n", string(out))
		return nil, err
	}

	// Try reading the preAPIConfig.
	var config preAPIConfig
	err = json.Unmarshal(out, &config)
	if err != nil {
		// Try to parse the old pre-API config. The main difference is that namespaces used to be a map, now it is a slice of structs.
		// The JSON marshaler will use the non-nested field before the nested one.
		type oldLibcontainerConfig struct {
			preAPIConfig
			OldNamespaces map[string]bool `json:"namespaces,omitempty"`
		}
		var oldConfig oldLibcontainerConfig
		err2 := json.Unmarshal(out, &oldConfig)
		if err2 != nil {
			// Use original error.
			return nil, err
		}

		// Translate the old pre-API config into the new config.
		config = oldConfig.preAPIConfig
		for ns := range oldConfig.OldNamespaces {
			config.Namespaces = append(config.Namespaces, configs.Namespace{
				Type: configs.NamespaceType(ns),
			})
		}
	}

	// Read the old state file as well.
	state, err := readState(dockerRoot, containerID)
	if err != nil {
		return nil, err
	}

	// Convert preAPIConfig + old state file to Config.
	// This only converts some of the fields, the ones we use.
	// You may need to add fields if the one you're interested in is not available.
	var result configs.Config
	result.Cgroups = new(configs.Cgroup)
	result.Rootfs = config.RootFs
	result.Hostname = config.Hostname
	result.Namespaces = config.Namespaces
	result.Capabilities = config.Capabilities
	for _, net := range config.Networks {
		n := &configs.Network{
			Name:              state.NetworkState.VethChild,
			Bridge:            net.Bridge,
			MacAddress:        net.MacAddress,
			Address:           net.Address,
			Gateway:           net.Gateway,
			IPv6Address:       net.IPv6Address,
			IPv6Gateway:       net.IPv6Gateway,
			HostInterfaceName: state.NetworkState.VethHost,
		}
		result.Networks = append(result.Networks, n)
	}
	result.Routes = config.Routes
	if config.Cgroups != nil {
		result.Cgroups = config.Cgroups
	}

	return &result, nil
}