Powershell Invoke-RestMethod - api

Question

I'm trying to create a powershell script to access DYN's API and perform checks/updates on DNS zones I use/test.
I'm following their API details and here's the first link, https://help.dyn.com/session-log-in/
Here's the beginning of the REST script I've put together:
$url = "https://api2.dynect.net/REST/Session/"
$body = #{customer_name='mahcompany';user_name='mahname';password='mahpass'}
Invoke-RestMethod -Method Post -Uri $url -Body $body
This produces the following results:
Invoke-RestMethod : The remote server returned an error: (406) Not Acceptable.
At line:12 char:9
+ $test = Invoke-RestMethod -Method Post -Uri $url -Body $body
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-> RestMethod], WebException
+ FullyQualifiedErrorId :
WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand
This is supposed to be a JSON query according to the DYN information, and so I've tried sevveral other examples of DYN's using CURL as a basis:
$json = #"{"customer_name":"yourcustomer","user_name":"youruser","password":"yourpass"}'
However this doesn't work either.
Can anyone point me in the right direction here? This can't be that crazy, I'm just trying to pass the parameters into a rest-method query string. Any help would be very much appreciated at this point.
-Sean

Answer 1

Content Type
Invoke-RestMethod -Method Post -Uri $url -Body $body -ContentType 'application/json'
This might be the problem if dyn.com is expecting a proper content type.
According to the documentation on Invoke-RestMethod:
If this parameter is omitted and the request method is POST, Invoke-RestMethod sets the content type to "application/x-www-form-urlencoded". Otherwise, the content type is not specified in the call.
ConvertTo-JSON
You don't have to create your JSON string manually. You can create a hashtable and then convert it:
$data = #{
customer = 'something'
name = 'whatever'
}
$data | ConvertTo-JSON
I'm not saying that you are definitely making malformed JSON, but this can help prevent that.