How to pass hashtables / objects from template to runbooks - json

Question

I have written a template and accompanying runbook. The template triggers the runbook. The template and the runbook are working fine, until I try and pass an object to one of the runbook's parameters. The Azure error is:
Error
"content":
{
"status": "Failed",
"error":
{
"code": "DeploymentFailed",
"message": "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/arm-debug for usage details.",
"details":
[
{
"code": "BadRequest",
"message": "{\r\n \"code\": \"BadRequest\",\r\n \"message\": \"{\\\"Message\\\":\\\"The request is invalid.\\\",\\\"ModelState\\\":{\\\"job.properties.parameters.MyTags\\\":[\\\"An error has occurred.\\\"]}}\"\r\n}"
}
]
}
}
I'm not sure what is meant by ModelState, however the job.properties.parameters.MyTags is pointing to the troublesome parameter.
I am sure it is something to do with the datatype. It may be because the parameter is being passed as a JSON object and the runbook cannot understand it. I'm more used to passing objects from PowerShell to templates.
Runbook (Update-ResourceGroupTags.ps1)
For testing, the runbook looks like:
param
(
[string]$ResourceGroupId,
$MyTags
)
Write-Output "ResourceGroupId: $ResourceGroupId"
Write-Output "MyTags: $($MyTags | Out-String)"
Write-Output "MyTagsType: $($MyTags.GetType() | Out-String)"
No authentication as it's not required yet and I have deliberately not typed $MyTags, although I have tried [object] and using `[parameter(Mandatory = $true)] just in case there's an unwritten / missed rule.
Goal
In brief, I create a complex object as a variable in the template and I want to pass it to a runbook's parameter as a single object. The values are dynamic and not known until deploy-time. Having to specify each parameter (test 8) in the runbook breaks this requirement.
I start a template with the New-AzureRmResourceGroupDeployment cmdlet.
I create a "complex object" variable:
"rolesTagObject": {
"db": "TestVm1",
"Server": "TestVm1",
"Client": "TestVm1"
}
The template runs a resource of "type" : "jobs".
The Runbook, run by jobs has a parameter MyTags which needs to take roleTagObject which I pass to jobs.properties.parameters.MyTags thus:
,
"parameters": {
"MyTags": "[variable('roleTagObject')]"
}
This is what's not working. If I break it down into each key (Test 8) it works.
My initial thought is to convert it to a single string and pass it to the runbook using json() function, but I don't know of a way to do that in a template.
Template (testRunRunbook.json)
I've put the template in a GIST so as not to make this question any longer.
https://gist.github.com/arcotek-ltd/7c606540980a45a3a7915ccae2e0b140
The template has been written so I can copy out the "resources":[] section into a different template. Hence why some variables and parameters may appear to be oddly named. As I said, the template works, apart from this issue.
PowerShell
I am calling the template with PowerShell, thus:
$Ticks = (Get-Date).Ticks.ToString()
$RGID = (Get-AzureRmResourceGroup -Name "MyResourceGroup").ResourceId
$MyTags = #{"TestTag2"="TestValue2"}
$JsonTagsHash = ($MyTags | ConvertTo-Json -Depth 20 | Out-String) -replace '\s',''
$TemplateParametersObject = #{
currentDateTimeInTicks = $Ticks
runbookParameters = #{
ResourceGroupId = $RGID
#"MyTags" = $MyTags #$JsonTagsHash
}
}
New-AzureRmResourceGroupDeployment `
-Name "Test_Runbook" `
-ResourceGroupName "MyResourceGroup" `
-Mode Incremental `
-DeploymentDebugLogLevel All `
-Force `
-TemplateFile "D:temp\testRunRunbook.json" `
-Verbose `
-TemplateParameterObject $TemplateParametersObject
I've tried the following tests:
Test 1
Uncomment $TemplateParametersObject.runbookParameters.MyTags:
$MyTags = #{"TestTag1"="TestValue1"}
$TemplateParametersObject = #{
currentDateTimeInTicks = $Ticks
runbookParameters = #{
ResourceGroupId = $RGID
MyTags = $MyTags
}
}
Result Fail - See error above.
Test 2
Replace $MyTags with $JsonTagsHash:
$MyTags = #{"TestTag2"="TestValue2"}
$JsonTagsHash = ($MyTags | ConvertTo-Json -Depth 20 | Out-String) -replace '\s',''
$TemplateParametersObject = #{
currentDateTimeInTicks = $Ticks
runbookParameters = #{
ResourceGroupId = $RGID
MyTags = $JsonTagsHash
}
}
Result: PASS Works as expected. Parameters are passed to runbook.
Test 2 works, but I need to be able to pass the parameters to the runbook that are generated inside the template at runtime. In other words, I can't use PowerShell. Inside the template at job.properties.parameters (Line 103 in the gist)
Test 3
To prove it's MyTags causing the issue, take it out completely:
"parameters": {
"ResourceGroupId": "[parameters('runbookParameters').ResourceGroupId]"
}
Result: No error, however, myTags are not passed (obviously).
Test 4
Create a variable object and pass that to the parameter:
"variables" : {
"rolesTagObject": {
"db": "TestVm1",
"Server": "TestVm1",
"Client": "TestVm1"
}
}
And back in job.properties.parameters:
"parameters": {
"ResourceGroupId": "[parameters('runbookParameters').ResourceGroupId]",
"MyTags": "[variables('rolesTagObject')]"
}
Result Fail - See error above.
Test 5
Try directly:
"parameters": {
"ResourceGroupId": "[parameters('runbookParameters').ResourceGroupId]",
"MyTags": {
"testTag5" : "testValue5"
}
}
Result Fail - See error above.
Test 6
Use the json() template function. Not that I expect it to work as it needs a string.
"parameters": {
"ResourceGroupId": "[parameters('runbookParameters').ResourceGroupId]",
"MyTags": "[json(variables('rolesTagObject'))]"
}
Result Fail. As predicted:
'The template language function 'json' expects an argument of type 'string'. The provided value is of type 'Object'.
Test 7
Try with the example provided my MS for json() template function:
"parameters": {
"ResourceGroupId": "[parameters('runbookParameters').ResourceGroupId]",
"MyTags": "[json('{\"a\": \"b\"}')]"
}
Result Fail- See error above. Interesting! But why? The working PowerShell test suggests it needs to be a JSON object. Is this not what json() does?
Test 8
Breaking out the object into individual key / values:
"parameters": {
"db": "[variables('rolesTagObject').db]",
"server": "[variables('rolesTagObject').server]",
"client": "[variables('rolesTagObject').client]"
}
I also have to change the parameters in the runbook from one to three.
Result Pass - but the idea of being able to pass an object is that it can have any number of key / value pairs. This way, not only does the variable and parameter have to be hardcoded, so does the runbook. Not very flexible.
I'm out of ideas. Any suggestions please?

Answer 1

The automation job parameters does not understand complex objects so you would want to pass in the parameter as a string and then convert back to Json within your runbook.
In your example, you could put quotes around the json object $MyTags so that it comes through as a string.
From
$TemplateParametersObject = #{
currentDateTimeInTicks = $Ticks
runbookParameters = #{
ResourceGroupId = $RGID
"MyTags" = $MyTags
}
}
to
$TemplateParametersObject = #{
currentDateTimeInTicks = $Ticks
runbookParameters = #{
ResourceGroupId = $RGID
"MyTags" = "$MyTags"
}
}
Then inside your runbook you could do
$MyTags = ConvertFrom-Json $MyTags
to get it back to a json object that you can use as needed.
If you are converting an object inside a template to a string, then you can just use the string function https://learn.microsoft.com/en-us/azure/azure-resource-manager/resource-group-template-functions-string#string
Example as shown in the comments:
"myParams": {
"Hello": "World",
"Location": {
"Country": "USA",
"State": "WA"
}
},
and then you can pass in this template object by just converting it to a string:
"properties": {
"runbook": {
"name": "[variables('runbookName')]"
},
"parameters": {
"ResourceGroupId": "[variables('myParams').Hello]",
"MyTags": "[String(variables('myParams'))]"
}
If the string function doesn't work, please let me know.
Hope this help,
Eamon