Add Host is failing in SDDC Manager UI with the error "Failed to load Host cluster details"

Products

• VMware Cloud Foundation 5.x

Issue/Introduction

Failed to load Host cluster details. Http failure response for https://xxxxxx.xxxx.xxx/ui/api/v1/clusters/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/hosts/queries/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx: 504 Gateway Timeout

Environment

VMware Cloud Foundation 5.2
VMware Cloud Foundation 5.2.1

Cause

The Host Discovery API takes longer than expected to return status code "200 OK" due to which a timeout is received on the UI. 

Resolution

Workaround:

Add the VxRail host(s) via the API explorer method.

1. Take a snapshot of the SDDC Manager VM.

2. Fill out the clusterExpansionSpec with the ipAddress, hostName, and root password for each host. 

{
"clusterExpansionSpec": {
"hostSpecs": [
{
"ipAddress": "xx.xx.xx.xxx",
"hostName" : "xxxxx.xxxxx.xxxxxx.xxxxx",
"username" : "root",
"password" : "xxxxxxxxx"
},
{
"ipAddress": "xx.xx.xx.xxx",
"hostName" : "xxxxx.xxxxx.xxxxxx.xxxxx",
"username" : "root",
"password" : "xxxxxxxxx"
}
]
}
}

3. Record the cluster ID where the hosts will be added to.

Developer Center > API Explorer > Clusters > GET /v1/clusters

4. Initiate the Add Host Validation from the API Explorer

SDDC Manager UI > Go to Developer Center > API Explorer > Clusters > POST /v1/clusters/{id}/validations

5.  Fetch the validation id from step-4 and poll on the Add Host Validation GET API until Validation is completed successfully

SDDC Manager UI > Go to Developer Center > API Explorer > Clusters > GET /v1/clusters/validations/{validationId}

6. Initiate the Add Host from the API Explorer

Developer Center > API Explorer > Clusters > PATCH /v1/clusters/{id}

7. Monitor the status of Add Host workflow from SDDC Manager UI task panel

Additional Information

The following error message may be present during the validation step (step 4):

"missing_inter_rack_expansion_data"

As such, the following value must be added to the end of the spec:

 ],
  "interRackExpansion":false
  }
}

Example:

{
"clusterExpansionSpec": {
"hostSpecs": [
{
"ipAddress": "xx.xx.xx.xxx",
"hostName" : "xxxxx.xxxxx.xxxxxx.xxxxx",
"username" : "root",
"password" : "xxxxxxxxx"
},
{
"ipAddress": "xx.xx.xx.xxx",
"hostName" : "xxxxx.xxxxx.xxxxxx.xxxxx",
"username" : "root",
"password" : "xxxxxxxxx"
}
],
  "interRackExpansion":false
}
}