datasource: remove FetchNetworkConfig step

Its easier to let each datasource grab all metadata in the FetchMetadata
stage than to break it into multiple stages.

datasource/metadata/digitalocean/metadata.go

@@ -61,8 +61,6 @@ type Metadata struct {
 }
 
 type metadataService struct {
-	interfaces Interfaces
-	dns        DNS
 	metadata.MetadataService
 }
 
@@ -81,9 +79,6 @@ func (ms *metadataService) FetchMetadata() (metadata datasource.Metadata, err er
 		return
 	}
 
-	ms.interfaces = m.Interfaces
-	ms.dns = m.DNS
-
 	if len(m.Interfaces.Public) > 0 {
 		if m.Interfaces.Public[0].IPv4 != nil {
 			metadata.PublicIPv4 = net.ParseIP(m.Interfaces.Public[0].IPv4.IPAddress)
@@ -105,17 +100,11 @@ func (ms *metadataService) FetchMetadata() (metadata datasource.Metadata, err er
 	for i, key := range m.PublicKeys {
 		metadata.SSHPublicKeys[strconv.Itoa(i)] = key
 	}
+	metadata.NetworkConfig = data
 
 	return
 }
 
-func (ms metadataService) FetchNetworkConfig(filename string) ([]byte, error) {
-	return json.Marshal(Metadata{
-		Interfaces: ms.interfaces,
-		DNS:        ms.dns,
-	})
-}
-
 func (ms metadataService) Type() string {
 	return "digitalocean-metadata-service"
 }

datasource/metadata/digitalocean/metadata_test.go

@@ -90,6 +90,34 @@ func TestFetchMetadata(t *testing.T) {
 					"0": "publickey1",
 					"1": "publickey2",
 				},
+				NetworkConfig: []byte(`{
+  "droplet_id": 1,
+  "user_data": "hello",
+  "vendor_data": "hello",
+  "public_keys": [
+    "publickey1",
+    "publickey2"
+  ],
+  "region": "nyc2",
+  "interfaces": {
+    "public": [
+      {
+        "ipv4": {
+          "ip_address": "192.168.1.2",
+          "netmask": "255.255.255.0",
+          "gateway": "192.168.1.1"
+        },
+        "ipv6": {
+          "ip_address": "fe00::",
+          "cidr": 126,
+          "gateway": "fe00::"
+        },
+        "mac": "ab:cd:ef:gh:ij",
+        "type": "public"
+      }
+    ]
+  }
+}`),
 			},
 		},
 		{