converting system.array object into json object in powershell

Question

I am logging into Azure using azure cli as follows:

$login = az login

The output is as follows:

[
  {
    "cloudName": "AzureCloud",
    "id": "xxxxxxxxxxxxxxxxxxx",
    "isDefault": false,
    "name": "ABC",
    "state": "Enabled",
    "tenantId": "yyyyyyyyyyyyy",
    "user": {
      "name": "xxxxxxx",
      "type": "user"
    }
  },
  {
    "cloudName": "AzureCloud",
    "id": "xxxxxxxxxxxxxxxxxxxx",
    "isDefault": true,
    "name": "PQR",
    "state": "Enabled",
    "tenantId": "yyyyyyyyyyyyyyyyyyyyyyyyyyyyy",
    "user": {
      "name": "xxxxxxxxxx",
      "type": "user"
    }
  }
]

I want to fetch the id value whose name is PQR. I was expecting i could do this as follows:

$login[1].id

But turns out $login is not a json object. I tried doing $login | ConvertTo-Json. Not working as i want.

Answer 1

az login in this case will just give you an array of lines of the output. You can check this with $login.GetType(), which will give you System.Object[]. You can use ConvertFrom-Json to convert the array to a PowerShell custom object. Then you can simply access the second object's subscription id property.

$login = az login

$json = $login | ConvertFrom-Json

Write-Output $json[1].id
# ID should be printed here

You can view the PSCustomObject properties with Get-Member:

PS C:\> $json | Get-Member

    TypeName: System.Management.Automation.PSCustomObject

Name        MemberType   Definition                                                                                
----        ----------   ----------                                                                                
Equals      Method       bool Equals(System.Object obj)                                                            
GetHashCode Method       int GetHashCode()                                                                         
GetType     Method       type GetType()                                                                            
ToString    Method       string ToString()                                                                         
cloudName   NoteProperty string cloudName=AzureCloud                                                               
id          NoteProperty string id=xxxx-xxxx-xxxx-xxxx                                        
isDefault   NoteProperty bool isDefault=True                                                                       
name        NoteProperty string name=xxxxxxx                                                 
state       NoteProperty string state=Enabled                                                                      
tenantId    NoteProperty string tenantId=xxxx-xxxx-xxxx-xxxx                               
user        NoteProperty System.Management.Automation.PSCustomObject user=@{name=xxxx@something.com; type=user}

You can also have a look at Connect-AzAccount, which is the Azure PowerShell way of logging in. A full tutorial can be found at Sign in with Azure PowerShell. az login is the Azure CLI method of logging in, which is cross platform compatible.