Microsoft Azure (Automation): Runbook passing Hash as Parameter - powershell

Question

I'm trying to pass a hash like {"server":"database","server2":"database_b"} as a parameter to a runbook on Microsoft Azure. But neither
[parameter(Mandatory=$true)] [hashtable]$ServersWithCorrespondingDatabase,
nor
[parameter(Mandatory=$true)] [object]$ServersWithCorrespondingDatabase,
seems to work?
In this example Runbook Gallery they go with the argument ChildRunbookInputParams as hashtable, like:
Start-ChildRunbook `
-ChildRunbookName "Update-VM" `
-ChildRunbookInputParams #{'VMName'='VM204';'Retries'=3} `
-AzureConnectionName "Visual Studio Ultimate with MSDN"
-AutomationAccountName "Contoso IT Automation Production" `
-WaitForJobCompletion $true `
-ReturnJobOutput $true `
-JobPollingIntervalInSeconds 20 `
-JobPollingTimeoutInSeconds 120
But somehow I can not pass the string #{"Server"="DB";"Server2"="DB3"} to my azure runbook as a parameter... Any idea?

Answer 1

In the runbook, you should define the parameter as [object] type, not [hashtable]. Are you starting the runbook through the Azure Automation portal, or inline via another runbook?
Assuming this is your runbook:
workflow a {
param(
[object] $obj
)
$obj
}
If via the portal, you need to specify the object parameter as JSON, ex:
{"server":"database","server2":"database_b"}
If via a runbook calling this runbook inline, specify it as a PowerShell object or hashtable:
a -Obj #{"server"="database";"server2"="database_b"}
For more info see http://azure.microsoft.com/blog/2014/08/12/azure-automation-runbook-input-output-and-nested-runbooks/
Edit: If you are trying to start this runbook specifically by calling the Start-ChildRunbook runbook within a runbook, it would look like this, since the Start-ChildRunbook runbook takes the parameters of the runbook to start as a hashtable, and in this case the value of one of those parameters is a hashtable/object itself:
$ValueForObjParam = #{"server"="database";"server2"="database_b"}
Start-ChildRunbook `
-ChildRunbookName "a" `
-ChildRunbookInputParams #{"obj"=$ValueForObjParam} `
-AzureConnectionName "Visual Studio Ultimate with MSDN" `
-AutomationAccountName "Contoso IT Automation Production" `
-WaitForJobCompletion $true `
-ReturnJobOutput $true `
-JobPollingIntervalInSeconds 20 `
-JobPollingTimeoutInSeconds 120

Answer 2

The script you refer to in the gallery uses a hashtable to specify all the params to the child runbook, not a single param of type hashtable. So, the child runbook probably has a param block like so:
workflow start-update-vm
{
param ($VMName, $retries)
#rest of code
}
You can, however, take a stringed json input and it will be converted into a hashtable/array as described here: http://blogs.technet.com/b/orchestrator/archive/2014/01/10/sma-capabilities-in-depth-runbook-input-output-and-nested-runbooks.aspx.