Thursday, 18 November 2021

ADF Release - Use script to enable certain Triggers

Case
During deployment of Azure Data Factory (ADF) via Azure DevOps pipelines I want to make sure that a certain trigger is only executed on Production and not on the lower environments like acceptance or test. How can we accomplish that without any manual operations? 
ADF Trigger
























Solution
This is possible with an extra PowerShell step. The standard deployment stages consists of three steps:
  • a pre-deployment script that stops all triggers.
  • the actual deployment
  • a post-deployment script that starts all triggers and cleans up old parts.
You could adjust the standard pre- and post deployment PowerShell script from Microsoft or create an additional PowerShell script if you don't want to mess around with the standard script from Microsoft. 

1) PowerShell
Below that additional script. Feel free to merge it with the standard script. The PowerShell file should be stored in the repository in the \CICD\PowerShell folder (see setup post).
PowerShell file for setting trigger status
























The new PowerShell script has five parameters which will be provided by the YAML pipeline (or release pipeline):
  1. DataFactoryName
    [string] Name of your Data Factory
  2. DataFactoryResourceGroup
    [string] Name of the Resource Group holding your ADF
  3. DataFactorySubscriptionId
    [string] Guid of the Azure Subscription hosting your ADF
  4. DisableAllTriggers
    [boolean] True or false indicating whether all triggers should be disabled (except triggers mentioned in next parameter)
  5. EnabledTriggers
    [string] Comma separated list with triggernames that should be enabled: "trigger1,trigger2"
The script consists of three parts. The first part checks all parameters. If one of them is incorrect then the scripts fails and stops. The second part is the optional disabling of all triggers (except the ones that we need enabled) and the last part of the script checks the list of triggers that should be enabled. If they are still disabled they will be enabled.
param
(
    [parameter(Mandatory = $true)] [String] $DataFactoryName,
    [parameter(Mandatory = $true)] [String] $DataFactoryResourceGroup,
    [parameter(Mandatory = $true)] [String] $DataFactorySubscriptionId,
    [parameter(Mandatory = $false)] [Bool] $DisableAllTriggers = $true,
    [parameter(Mandatory = $true)] [String] $EnabledTriggers # comma separated list
)



##############################################
# Check provided information
##############################################
$ErrorActionPreference = "Stop"

# Setting one subscription on active (fails with non existing)
Write-Host "Checking existance Subscription Id [$($DataFactorySubscriptionId)]."
$Subscription = Get-AzSubscription -SubscriptionId $DataFactorySubscriptionId `
                                   -WarningAction Ignore
Write-Host "- Subscription [$($Subscription.Name)] found."
Set-AzContext -Subscription $DataFactorySubscriptionId `
              -WarningAction Ignore > $null
Write-Host "- Subscription [$($Subscription.Name)] is active."


# Checking whether resource group exists (fails with non existing)
Write-Host "Checking existance Resource Group [$($DataFactoryResourceGroup)]."
Get-AzResourceGroup -Name $DataFactoryResourceGroup > $null
Write-Host "- Resource Group [$($DataFactoryResourceGroup)] found."


# Checking whether provided data factory exists (fails with non existing)
Write-Host "Checking existance Data Factory [$($DataFactoryName)]."
Get-AzDataFactoryV2 -ResourceGroupName $DataFactoryResourceGroup `
                    -Name $DataFactoryName > $null
Write-Host "- Data Factory [$($DataFactoryName)] found."


# Checking provided triggernames, first split into array
$EnabledTriggersArray = $EnabledTriggers.Split(",")
Write-Host "Checking existance of ($($EnabledTriggersArray.Count)) provided triggernames."


# Loop through all provided triggernames
foreach ($EnabledTrigger in $EnabledTriggersArray)
{ 
    # Get Trigger by name
    $CheckTrigger = Get-AzDataFactoryV2Trigger -ResourceGroupName $DataFactoryResourceGroup `
                                               -DataFactoryName $DataFactoryName `
                                               -Name $EnabledTrigger `
                                               -ErrorAction Ignore # To be able to provide more detailed error

    # Check if trigger was found
    if (!$CheckTrigger)
    {
        throw "Trigger $($EnabledTrigger) not found in data dactory $($DataFactoryName) within resource group $($DataFactoryResourceGroup)"
    }
}
Write-Host "- All ($($EnabledTriggersArray.Count)) provided triggernames found in data dactory $($DataFactoryName) within resource group $($DataFactoryResourceGroup)"



##############################################
# Disable triggers
##############################################
# Check if all trigger should be disabled
if ($DisableAllTriggers)
{
    # Get all enabled triggers and stop them (unless they should be enabled)
    Write-Host "Getting all enabled triggers that should be disabled."
    $CurrentTriggers = Get-AzDataFactoryV2Trigger -ResourceGroupName $DataFactoryResourceGroup `
                                                   -DataFactoryName $DataFactoryName `
                       | Where-Object {$_.RuntimeState -ne 'Stopped'} `
                       | Where-Object {$EnabledTriggersArray.Contains($_.Name) -eq $false}

    # Loop through all found triggers
    Write-Host "- Number of triggers to disable: $($CurrentTriggers.Count)."
    foreach ($CurrentTrigger in $CurrentTriggers)
    {
        # Stop trigger
        Write-Host "- Stopping trigger [$($CurrentTrigger.Name)]."
        Stop-AzDataFactoryV2Trigger -ResourceGroupName $DataFactoryResourceGroup -DataFactoryName $DataFactoryName -Name $CurrentTrigger.Name -Force > $null
    }
}



##############################################
# Enable triggers
##############################################
# Loop through provided triggernames and enable them
Write-Host "Enable all ($($EnabledTriggersArray.Count)) provided triggers."
foreach ($EnabledTrigger in $EnabledTriggersArray)
{                   
    # Get trigger details
    $CheckTrigger = Get-AzDataFactoryV2Trigger -ResourceGroupName $DataFactoryResourceGroup `
                                               -DataFactoryName $DataFactoryName `
                                               -Name $EnabledTrigger

    # Check status of trigger
    if ($CheckTrigger.RuntimeState -ne "Started")
    {
        Write-Host "- Trigger [$($EnabledTrigger)] starting"
        Start-AzDataFactoryV2Trigger -ResourceGroupName $DataFactoryResourceGroup `
                                     -DataFactoryName $DataFactoryName `
                                     -Name $EnabledTrigger `
                                     -Force > $null
    }
    else
    {
        Write-Host "- Trigger [$($EnabledTrigger)] already started"
    }
}

2) YAML Pipeline
You can now extend the existing YAML pipeline with an extra step. Make sure that all parameters for this script are available as variables in the variable group (under Pipelines, Library) and make sure to pass them to the second YAML pipeline as parameters. If you followed the previous blogs then you only need to add EnabledTriggers as variable and a YAML parameter.
          ###################################
          # Enable certain triggers and disable rest
          ###################################
          - task: AzurePowerShell@5
            displayName: '6 Enable certain triggers and disable rest'
            inputs:
              azureSubscription: 'sc_adf-devopssp'
              pwsh: true
              azurePowerShellVersion: LatestVersion
              scriptType: filePath
              scriptPath: '$(Pipeline.Workspace)\s\CICD\powershell\SetTriggers.ps1'
              scriptArguments: > # Use this to avoid newline characters in multiline string
                -DataFactoryName $(DataFactoryName)
                -DataFactoryResourceGroup $(DataFactoryResourceGroupName)
                -DataFactorySubscriptionId $(DataFactorySubscriptionId)
                -DisableAllTriggers $true
                -EnabledTriggers $(EnabledTriggers) # format: "prd_daily_4am,prd_daily_1pm"
The result of running the pipeline










Conclusion

In this post you learned how to enable only certain triggers for a specific environment. This makes it easy to generate a trigger in development for the production environment. The downside (for some) is ofcourse that you get an extra piece of code to maintain. In a next post we will show that you can also accomplish this without writing code via the ARM template. However the trigger property runtimeState cannot be set via the ARM template, so a workaroumd is necessary for the nocode variant.


No comments:

Post a Comment

All comments will be verified first to avoid URL spammers