Exception when creating a Databricks cluster via REST API - powershell

Question

I can successfully create a Databricks cluster via REST API using the following in Postman:
POST /api/2.0/clusters/create HTTP/1.1
Host: adb-xxxxxxxxxxxxxxxx.xx.azuredatabricks.net
Authorization: Bearer eyJ <REMOVED> EJA
Content-Type: application/json
{
"cluster_name": "xxxxxxx-xxxxx-xx-x-xxx-##-xxxxxxx-####",
"spark_version": "5.5.x-scala2.11",
"node_type_id": "Standard_DS3_v2",
"autoscale" : {
"min_workers": 2,
"max_workers": 10
},
"autotermination_minutes": 30
}
When I convert the above for use with PowerShell's Invoke-RestMethod, I get a WebException. When running the script in the Windows PowerShell ISE (running as Administrator) the following results:
The remote server returned an error: (400) Bad Request.
at <ScriptBlock>, <No file>: line 91
System.Net.WebException: The remote server returned an error: (400) Bad Request.
at Microsoft.PowerShell.Commands.WebRequestPSCmdlet.GetResponse(WebRequest request)
at Microsoft.PowerShell.Commands.WebRequestPSCmdlet.ProcessRecord()
The Azure AD token generated in PowerShell is the same token used successfully in Postman. This issue doesn't appear to be related to a bad token.
Here is the PowerShell that results in the exception:
<SCRIPT>
... API calls re: AAD Token omitted ...
Write-Host "Create Databricks Cluster"
$body = #{
cluster_name = "xxxxxxx-xxxxx-xx-x-xxx-##-xxxxxxx-####"
spark_version = "5.5.x-scala2.11"
node_type_id = "Standard_DS3_v2"
autoscale = #{
min_workers = 2
max_workers = 10
}
autotermination_minutes = 30
}
$headers = #{
"Authorization"="Bearer " + "$apiKey";
"Content-Type"="application/json";
}
$uri = "$uriroot/2.0/clusters/create"
Write-Host $uri
Write-Host $headers
try { $response = Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body $body }
catch {
Write-Host $_
Write-Host $_.ScriptStackTrace
Write-Host $_.Exception
Write-Host $_.ErrorDetails
}
Write-Host $response
</SCRIPT>
What is the PowerShell version missing but present in Postman?

Answer 1

Here's a solution I found. Use ConvertTo-Json on the $body variable passed to the -Body command-line argument.
try { $response = Invoke-RestMethod -Method 'Post' -Uri $uri -Headers $headers -Body (ConvertTo-Json $body) }