Add aliyun datasource (#2169)

config/cloudinit/datasource/metadata/aliyun/metadata.go

@@ -0,0 +1,85 @@
+package aliyun
+
+import (
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/rancher/os/netconf"
+
+	"github.com/rancher/os/config/cloudinit/datasource"
+	"github.com/rancher/os/config/cloudinit/datasource/metadata"
+)
+
+const (
+	DefaultAddress = "http://100.100.100.200/"
+	apiVersion     = "2016-01-01/"
+	userdataPath   = apiVersion + "user-data/"
+	metadataPath   = apiVersion + "meta-data/"
+)
+
+type MetadataService struct {
+	metadata.Service
+}
+
+func NewDatasource(root string) *MetadataService {
+	if root == "" {
+		root = DefaultAddress
+	}
+	return &MetadataService{metadata.NewDatasource(root, apiVersion, userdataPath, metadataPath, nil)}
+}
+
+func (ms MetadataService) AvailabilityChanges() bool {
+	// TODO: if it can't find the network, maybe we can start it?
+	return false
+}
+
+func (ms MetadataService) FetchMetadata() (metadata datasource.Metadata, err error) {
+	// see https://www.alibabacloud.com/help/faq-detail/49122.htm
+	metadata.NetworkConfig = netconf.NetworkConfig{}
+
+	enablePublicKey := false
+
+	rootContents, err := ms.FetchAttributes("")
+	if err != nil {
+		return metadata, err
+	}
+	for _, c := range rootContents {
+		if c == "public-keys/" {
+			enablePublicKey = true
+			break
+		}
+	}
+	if !enablePublicKey {
+		return metadata, fmt.Errorf("The public-keys should be enable in %s", ms.Type())
+	}
+
+	keynames, err := ms.FetchAttributes("public-keys/")
+	if err != nil {
+		return metadata, err
+	}
+
+	metadata.SSHPublicKeys = map[string]string{}
+	for _, k := range keynames {
+		k = strings.TrimRight(k, "/")
+		sshkey, err := ms.FetchAttribute(fmt.Sprintf("public-keys/%s/openssh-key", k))
+		if err != nil {
+			return metadata, err
+		}
+		metadata.SSHPublicKeys[k] = sshkey
+		log.Printf("Found SSH key for %q\n", k)
+	}
+
+	if hostname, err := ms.FetchAttribute("hostname"); err == nil {
+		metadata.Hostname = hostname
+		log.Printf("Found hostname  %s\n", hostname)
+	} else {
+		return metadata, err
+	}
+
+	return metadata, nil
+}
+
+func (ms MetadataService) Type() string {
+	return "aliyun-metadata-service"
+}