Add MergeMetadata and MergeMetadataAsync functions for metadata (#473)

Also refactor metadata CRUD functions

Signed-off-by: abarreiro <abarreiro@vmware.com>

Author: adambarreiro

.changes/v2.16.0/473-features.md

@@ -0,0 +1,7 @@
+* Added `AdminCatalog.MergeMetadata`,`AdminCatalog.MergeMetadataAsync`, `AdminOrg.MergeMetadata`, `AdminOrg.MergeMetadataAsync`, 
+`CatalogItem.MergeMetadata`, `CatalogItem.MergeMetadataAsync`, `Disk.MergeMetadata`, `Disk.MergeMetadataAsync`, `Media.MergeMetadata`, 
+`Media.MergeMetadataAsync`, `MediaRecord.MergeMetadata`, `MediaRecord.MergeMetadataAsync`, `OpenAPIOrgVdcNetwork.MergeMetadata`, 
+`OpenAPIOrgVdcNetwork.MergeMetadataAsync`, `OrgVDCNetwork.MergeMetadata`, `OrgVDCNetwork.MergeMetadataAsync`, 
+`VApp.MergeMetadata`, `VApp.MergeMetadataAsync`, `VAppTemplate.MergeMetadata`, `VAppTemplate.MergeMetadataAsync`, 
+`VM.MergeMetadata`, `VM.MergeMetadataAsync`, `Vdc.MergeMetadata`, `Vdc.MergeMetadataAsync` to merge metadata, 
+which both updates existing metadata with same key and adds new entries for the non-existent ones [GH-473]

govcd/api.go

@@ -768,6 +768,11 @@ func (client *Client) RemoveProvidedCustomHeaders(values map[string]string) {
 	}
 }
 
+// Retrieves the administrator URL of a given HREF
+func getAdminURL(href string) string {
+	return strings.ReplaceAll(href, "/api/", "/api/admin/")
+}
+
 // ---------------------------------------------------------------------
 // The following functions are needed to avoid strict Coverity warnings
 // ---------------------------------------------------------------------

govcd/api_vcd_test.go

@@ -1703,28 +1703,21 @@ func (vcd *TestVCD) findFirstVapp() VApp {
 		return VApp{}
 	}
 	wantedVapp := vcd.vapp.VApp.Name
-	vappName := ""
-	for _, res := range vdc.Vdc.ResourceEntities {
-		for _, item := range res.ResourceEntity {
-			// Finding a named vApp, if it was defined in config
-			if wantedVapp != "" {
-				if item.Name == wantedVapp {
-					vappName = item.Name
-					break
-				}
-			} else {
-				// Otherwise, we get the first vApp from the vDC list
+	if wantedVapp == "" {
+		// As no vApp is defined in config, we search for one randomly
+		for _, res := range vdc.Vdc.ResourceEntities {
+			for _, item := range res.ResourceEntity {
 				if item.Type == "application/vnd.vmware.vcloud.vApp+xml" {
-					vappName = item.Name
+					wantedVapp = item.Name
 					break
 				}
 			}
 		}
 	}
-	if wantedVapp == "" {
+	vapp, err := vdc.GetVAppByName(wantedVapp, false)
+	if err != nil {
 		return VApp{}
 	}
-	vapp, _ := vdc.GetVAppByName(vappName, false)
 	return *vapp
 }