ui: fix add Vmware cluster (#4663)

When adding a cluster from existing host-datacenter UI shoudl list and autofill host, DC name while making addCluster API call.

Signed-off-by: Abhishek Kumar <abhishek.mrt22@gmail.com>

ui/src/views/infra/ClusterAdd.vue

@@ -216,11 +216,35 @@ export default {
 
       if (this.hypervisor === 'VMware') {
         this.clustertype = 'ExternalManaged'
+        if ((this.host === null || this.host.length === 0) &&
+          (this.dataCenter === null || this.dataCenter.length === 0)) {
+          api('listVmwareDcs', {
+            zoneid: this.zoneId
+          }).then(response => {
+            var vmwaredcs = response.listvmwaredcsresponse.VMwareDC
+            if (vmwaredcs !== null) {
+              this.host = vmwaredcs[0].vcenter
+              this.dataCenter = vmwaredcs[0].name
+            }
+            this.addCluster()
+          }).catch(error => {
+            this.$notification.error({
+              message: `${this.$t('label.error')} ${error.response.status}`,
+              description: error.response.data.listvmwaredcsresponse.errortext,
+              duration: 0
+            })
+          })
+          return
+        }
+      }
+      this.addCluster()
+    },
+    addCluster () {
+      if (this.hypervisor === 'VMware') {
         const clusternameVal = this.clustername
         this.url = `http://${this.host}/${this.dataCenter}/${clusternameVal}`
         this.clustername = `${this.host}/${this.dataCenter}/${clusternameVal}`
       }
-
       this.loading = true
       this.parentToggleLoading()
       api('addCluster', {}, 'POST', {