datasource: Add FetchNetworkConfig

FetchNetworkConfig is currently only used by ConfigDrive to read the
network config file from the disk.

coreos-cloudinit.go

@@ -132,6 +132,17 @@ func main() {
 		fmt.Printf("Failed to parse meta-data: %v\n", err)
 		die()
 	}
+
+	if ccm != nil {
+		fmt.Printf("Fetching network config from datasource of type %q\n", ds.Type())
+		netconfBytes, err := ds.FetchNetworkConfig(ccm.NetworkConfigPath)
+		if err != nil {
+			fmt.Printf("Failed fetching network config from datasource: %v\n", err)
+			die()
+		}
+		ccm.NetworkConfig = string(netconfBytes)
+	}
+
 	if ud, err := initialize.ParseUserData(userdata); err != nil {
 		fmt.Printf("Failed to parse user-data: %v\n", err)
 		die()

datasource/configdrive/configdrive.go

@@ -41,6 +41,10 @@ func (cd *configDrive) FetchUserdata() ([]byte, error) {
 	return cd.tryReadFile(path.Join(cd.openstackVersionRoot(), "user_data"))
 }
 
+func (cd *configDrive) FetchNetworkConfig(filename string) ([]byte, error) {
+	return cd.tryReadFile(path.Join(cd.openstackRoot(), filename))
+}
+
 func (cd *configDrive) Type() string {
 	return "cloud-drive"
 }

datasource/datasource.go

@@ -6,5 +6,6 @@ type Datasource interface {
 	ConfigRoot() string
 	FetchMetadata() ([]byte, error)
 	FetchUserdata() ([]byte, error)
+	FetchNetworkConfig(string) ([]byte, error)
 	Type() string
 }

datasource/file/file.go

@@ -34,6 +34,10 @@ func (f *localFile) FetchUserdata() ([]byte, error) {
 	return ioutil.ReadFile(f.path)
 }
 
+func (f *localFile) FetchNetworkConfig(filename string) ([]byte, error) {
+	return nil, nil
+}
+
 func (f *localFile) Type() string {
 	return "local-file"
 }

datasource/metadata/cloudsigma/server_context.go

@@ -126,6 +126,10 @@ func (scs *serverContextService) FetchUserdata() ([]byte, error) {
 	return []byte(userData), nil
 }
 
+func (scs *serverContextService) FetchNetworkConfig(a string) ([]byte, error) {
+	return nil, nil
+}
+
 func isBase64Encoded(field string, userdata map[string]string) bool {
 	base64Fields, ok := userdata["base64_fields"]
 	if !ok {

datasource/metadata/metadata.go

@@ -38,6 +38,10 @@ func (ms MetadataService) FetchUserdata() ([]byte, error) {
 	return ms.FetchData(ms.UserdataUrl())
 }
 
+func (ms MetadataService) FetchNetworkConfig(filename string) ([]byte, error) {
+	return nil, nil
+}
+
 func (ms MetadataService) FetchData(url string) ([]byte, error) {
 	if data, err := ms.Client.GetRetry(url); err == nil {
 		return data, err

datasource/proc_cmdline/proc_cmdline.go

@@ -66,6 +66,10 @@ func (c *procCmdline) FetchUserdata() ([]byte, error) {
 	return cfg, nil
 }
 
+func (c *procCmdline) FetchNetworkConfig(filename string) ([]byte, error) {
+	return nil, nil
+}
+
 func (c *procCmdline) Type() string {
 	return "proc-cmdline"
 }

datasource/url/url.go

@@ -1,6 +1,8 @@
 package url
 
-import "github.com/coreos/coreos-cloudinit/pkg"
+import (
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
 
 type remoteFile struct {
 	url string
@@ -33,6 +35,10 @@ func (f *remoteFile) FetchUserdata() ([]byte, error) {
 	return client.GetRetry(f.url)
 }
 
+func (f *remoteFile) FetchNetworkConfig(filename string) ([]byte, error) {
+	return nil, nil
+}
+
 func (f *remoteFile) Type() string {
 	return "url"
 }

initialize/config.go

@@ -3,7 +3,6 @@ package initialize
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"path"
 
@@ -42,6 +41,7 @@ type CloudConfig struct {
 	Users             []system.User
 	ManageEtcHosts    EtcHosts `yaml:"manage_etc_hosts"`
 	NetworkConfigPath string
+	NetworkConfig     string
 }
 
 type warner func(format string, v ...interface{})
@@ -258,17 +258,11 @@ func Apply(cfg CloudConfig, env *Environment) error {
 	}
 
 	if env.NetconfType() != "" {
-		filename := path.Join(env.ConfigRoot(), cfg.NetworkConfigPath)
-		log.Printf("Attempting to read config from %q\n", filename)
-		netconfBytes, err := ioutil.ReadFile(filename)
-		if err != nil {
-			return err
-		}
-
 		var interfaces []network.InterfaceGenerator
+		var err error
 		switch env.NetconfType() {
 		case "debian":
-			interfaces, err = network.ProcessDebianNetconf(string(netconfBytes))
+			interfaces, err = network.ProcessDebianNetconf(cfg.NetworkConfig)
 		default:
 			return fmt.Errorf("Unsupported network config format %q", env.NetconfType())
 		}