metadata-service: Add metadata-service datasource

Move the old metadata-service datasource to url datasource. This new datasource
checks for the existance of meta-data.json and if it doesn't exist, walks the
meta-data directory to build a metadata blob.

datasource/configdrive.go

@@ -14,24 +14,24 @@ func NewConfigDrive(root string) *configDrive {
 	return &configDrive{path.Join(root, "openstack")}
 }
 
-func (self *configDrive) ConfigRoot() string {
-	return self.root
+func (cd *configDrive) ConfigRoot() string {
+	return cd.root
 }
 
-func (self *configDrive) FetchMetadata() ([]byte, error) {
-	return self.readFile("meta_data.json")
+func (cd *configDrive) FetchMetadata() ([]byte, error) {
+	return cd.readFile("meta_data.json")
 }
 
-func (self *configDrive) FetchUserdata() ([]byte, error) {
-	return self.readFile("user_data")
+func (cd *configDrive) FetchUserdata() ([]byte, error) {
+	return cd.readFile("user_data")
 }
 
-func (self *configDrive) Type() string {
+func (cd *configDrive) Type() string {
 	return "cloud-drive"
 }
 
-func (self *configDrive) readFile(filename string) ([]byte, error) {
-	data, err := ioutil.ReadFile(path.Join(self.root, "latest", filename))
+func (cd *configDrive) readFile(filename string) ([]byte, error) {
+	data, err := ioutil.ReadFile(path.Join(cd.root, "latest", filename))
 	if os.IsNotExist(err) {
 		err = nil
 	}

datasource/file.go

@@ -12,18 +12,18 @@ func NewLocalFile(path string) *localFile {
 	return &localFile{path}
 }
 
-func (self *localFile) ConfigRoot() string {
+func (f *localFile) ConfigRoot() string {
 	return ""
 }
 
-func (self *localFile) FetchMetadata() ([]byte, error) {
+func (f *localFile) FetchMetadata() ([]byte, error) {
 	return []byte{}, nil
 }
 
-func (self *localFile) FetchUserdata() ([]byte, error) {
-	return ioutil.ReadFile(self.path)
+func (f *localFile) FetchUserdata() ([]byte, error) {
+	return ioutil.ReadFile(f.path)
 }
 
-func (self *localFile) Type() string {
+func (f *localFile) Type() string {
 	return "local-file"
 }

datasource/metadata_service.go

@@ -1,28 +1,97 @@
 package datasource
 
-import "github.com/coreos/coreos-cloudinit/pkg"
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
 
 type metadataService struct {
 	url string
 }
 
-func NewMetadataService(url string) *metadataService {
-	return &metadataService{url}
+type getter interface {
+	Get(string) ([]byte, error)
 }
 
-func (self *metadataService) ConfigRoot() string {
+func NewMetadataService(url string) *metadataService {
+	return &metadataService{strings.TrimSuffix(url, "/")}
+}
+
+func (ms *metadataService) ConfigRoot() string {
 	return ""
 }
 
-func (self *metadataService) FetchMetadata() ([]byte, error) {
-	return []byte{}, nil
+func (ms *metadataService) FetchMetadata() ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return fetchMetadata(client, ms.url)
 }
 
 func (ms *metadataService) FetchUserdata() ([]byte, error) {
 	client := pkg.NewHttpClient()
-	return client.Get(ms.url)
+	return client.Get(ms.url + "/latest/user-data")
 }
 
 func (ms *metadataService) Type() string {
 	return "metadata-service"
 }
+
+func fetchMetadata(client getter, url string) ([]byte, error) {
+	if metadata, err := client.Get(url + "/latest/meta-data.json"); err == nil {
+		return metadata, nil
+	} else if _, ok := err.(pkg.ErrTimeout); ok {
+		return nil, err
+	}
+
+	attrs, err := fetchChildAttributes(client, url+"/latest/meta-data/")
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(attrs)
+}
+
+func fetchAttributes(client getter, url string) ([]string, error) {
+	resp, err := client.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	scanner := bufio.NewScanner(bytes.NewBuffer(resp))
+	data := make([]string, 0)
+	for scanner.Scan() {
+		data = append(data, strings.Split(scanner.Text(), "=")[0])
+	}
+	return data, scanner.Err()
+}
+
+func fetchAttribute(client getter, url string) (interface{}, error) {
+	if attrs, err := fetchAttributes(client, url); err == nil {
+		return attrs[0], nil
+	} else {
+		return "", err
+	}
+}
+
+func fetchChildAttributes(client getter, url string) (interface{}, error) {
+	attrs := make(map[string]interface{})
+	attrList, err := fetchAttributes(client, url)
+	if err != nil {
+		return nil, err
+	}
+	for _, attr := range attrList {
+		var fetchFunc func(getter, string) (interface{}, error)
+		if strings.HasSuffix(attr, "/") {
+			fetchFunc = fetchChildAttributes
+		} else {
+			fetchFunc = fetchAttribute
+		}
+		if value, err := fetchFunc(client, url+attr); err == nil {
+			attrs[strings.TrimSuffix(attr, "/")] = value
+		} else {
+			return nil, err
+		}
+	}
+	return attrs, nil
+}

datasource/proc_cmdline.go

@@ -22,16 +22,16 @@ func NewProcCmdline() *procCmdline {
 	return &procCmdline{Location: ProcCmdlineLocation}
 }
 
-func (self *procCmdline) ConfigRoot() string {
+func (c *procCmdline) ConfigRoot() string {
 	return ""
 }
 
-func (self *procCmdline) FetchMetadata() ([]byte, error) {
+func (c *procCmdline) FetchMetadata() ([]byte, error) {
 	return []byte{}, nil
 }
 
-func (self *procCmdline) FetchUserdata() ([]byte, error) {
-	contents, err := ioutil.ReadFile(self.Location)
+func (c *procCmdline) FetchUserdata() ([]byte, error) {
+	contents, err := ioutil.ReadFile(c.Location)
 	if err != nil {
 		return nil, err
 	}
@@ -51,7 +51,7 @@ func (self *procCmdline) FetchUserdata() ([]byte, error) {
 	return cfg, nil
 }
 
-func (self *procCmdline) Type() string {
+func (c *procCmdline) Type() string {
 	return "proc-cmdline"
 }
 

datasource/url.go

@@ -0,0 +1,28 @@
+package datasource
+
+import "github.com/coreos/coreos-cloudinit/pkg"
+
+type remoteFile struct {
+	url string
+}
+
+func NewRemoteFile(url string) *remoteFile {
+	return &remoteFile{url}
+}
+
+func (f *remoteFile) ConfigRoot() string {
+	return ""
+}
+
+func (f *remoteFile) FetchMetadata() ([]byte, error) {
+	return []byte{}, nil
+}
+
+func (f *remoteFile) FetchUserdata() ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return client.Get(f.url)
+}
+
+func (f *remoteFile) Type() string {
+	return "url"
+}