Terraform breaking Azure Logic App connections - azure

Question

I am creating an Azure Logic App (using it to unzip to a blob storage). For this I need the Logic App workflow and a connection to the blob storage. I create the empty Logic App Workflow with Terraform and the actual Logic App implementation with Visual Studio that I just then deploy to the Logic App created with tf.
I use following tf code to create the empty Logic App Workflow:
resource "azurerm_logic_app_workflow" "logic_unzip" {
name = "ngh-${var.deployment}-unziplogic"
resource_group_name = "${azurerm_resource_group.rg.name}"
location = "${azurerm_resource_group.rg.location}"
}
As the Logic App needs connection to the Blob storage I will use following template to create it:
resource "azurerm_template_deployment" "depl_connection_azureblob" {
name = "azureblob"
resource_group_name = "${azurerm_resource_group.rg.name}"
template_body = <<DEPLOY
{
"$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"connection_name": {"type": "string"},
"storage_name": {"type": "string"},
"storage_access_key": {"type": "string"},
"location": {"type": "string"},
"api_id": {"type": "string"}
},
"resources": [{
"type": "Microsoft.Web/connections",
"name": "[parameters('connection_name')]",
"apiVersion": "2016-06-01",
"location": "[parameters('location')]",
"scale": null,
"properties": {
"displayName": "[parameters('connection_name')]",
"api": {
"id": "[parameters('api_id')]"
},
"parameterValues": {
"accountName": "[parameters('storage_name')]",
"accessKey": "[parameters('storage_access_key')]"
}
},
"dependsOn": []
}]
}
DEPLOY
parameters = {
"connection_name" = "azureblob"
"storage_name" = "${azurerm_storage_account.sa-main.name}"
"storage_access_key" = "${azurerm_storage_account.sa-main.primary_access_key}"
"location" = "${azurerm_resource_group.rg.location}"
"api_id" = "${data.azurerm_subscription.current.id}/providers/Microsoft.Web/locations/${azurerm_resource_group.rg.location}/managedApis/azureblob"
}
deployment_mode = "Incremental"
}
Running plan and apply, these work perfect. In Visual Studio I can then create the Logic App and use the azureblob connection to select the correct blob storage.
Now, when I have deployed the Logic App Workflow from Visual Studio and run terraform plan I get following changes:
An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
~ update in-place
Terraform will perform the following actions:
~ azurerm_logic_app_workflow.logic_unzip
parameters.$connections: "" => ""
parameters.%: "1" => "0"
Plan: 0 to add, 1 to change, 0 to destroy.
Running the apply command now will break the Logic App as it removes the bound connection. Clearly the Visual Studio deploy has created the binding between the Logic App and the connection.
How can I tell Terraform not to remove the connections (created by the Visual Studio deploy) from the Logic App?

Answer 1

Terraform is not aware of the resources deployed in the arm template, so it detects the state change and tries to "fix" that. I dont see any CF resources for logic app connections, so seeing how it detects that parameters.connections changed from 0 to 1 adding your connection directly to the workflow resource might work, but CF mentions : Any parameters specified must exist in the Schema defined in workflow_schema, but I dont see connections in the schema, which is a bit weird, but I assume I'm misreading the schema
you can also use ignore_changes:
lifecycle {
ignore_changes = [
"parameters.$connections"
]
}
according to the comments and this
reading:
https://www.terraform.io/docs/configuration/resources.html#ignore_changes