Merged PR 2: Terraform script for EventHub

Since ability to manage eventhub namespace firewall and virtual network rules from Terraform is not supported yet (hashicorp/terraform-provider-azurerm#2579) we need to use ARM templates.

Another challenge - azurerm_template_deployment fails to pass "array" type parameters properly with error
Error: azurerm_template_deployment.eventhub: parameters (subnetIds): '' expected type 'string', got unconvertible type '[]interface {}’
(hashicorp/terraform-provider-azurerm#2579 closed but doesn’t seem resolved)

Related work items: #47

.gitignore

@@ -12,7 +12,8 @@ crash.log
 # .tfvars files are managed as part of configuration and so should be included in
 # version control.
 #
-# example.tfvars
+*.tfvars
+!sample.tfvars
 
 # Ignore override files as they are usually used to override resources locally and so
 # are not checked in

terraform/azure/eventhub.tf

@@ -0,0 +1,103 @@
+
+resource "azurerm_template_deployment" "eventhub" {
+  name                = "${var.prefix}-eventhub"
+  resource_group_name = "${azurerm_resource_group.rg.name}"
+
+  template_body = <<DEPLOY
+  {
+    "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "parameters": {
+      "prefix": {
+        "type": "string",
+        "defaultValue": "[take(tolower(uniqueString(resourceGroup().id)), 12)]"
+      },
+      "subnetIds": {
+        "type": "array",
+        "defaultValue": ${var.subnetIds}
+      },
+      "messageRetentionInDays": {
+        "type": "string",
+        "defaultValue": "1"
+      },
+      "partitionCount": {
+        "type": "string",
+        "defaultValue": "4"
+      }
+    },
+    "variables": {
+      "ehNamespace": "[concat('eh-', parameters('prefix'))]",
+      "ehName": "telemetry",
+      "consumerGroups": [
+        "databricks"
+      ]
+    },
+    "resources": [
+      {
+        "apiVersion": "2017-04-01",
+        "type": "Microsoft.EventHub/namespaces",
+        "name": "[variables('ehNamespace')]",
+        "location": "[resourceGroup().location]",
+        "sku": {
+          "name": "Standard",
+          "tier": "Standard"
+        },
+        "properties": {
+          "kafkaEnabled": true
+        }
+      },
+      {
+        "dependsOn": [
+          "[resourceId('Microsoft.EventHub/namespaces', variables('ehNamespace'))]"
+        ],
+        "apiVersion": "2017-04-01",
+        "type": "Microsoft.EventHub/namespaces/eventhubs",
+        "name": "[concat(variables('ehNamespace'), '/', variables('ehName'))]",
+        "properties": {
+          "messageRetentionInDays": "[parameters('messageRetentionInDays')]",
+          "partitionCount": "[parameters('partitionCount')]"
+        }
+      },
+      {
+        "dependsOn": [
+          "[resourceId('Microsoft.EventHub/namespaces/eventHubs', variables('ehNamespace'), variables('ehName'))]"
+        ],
+        "copy": {
+          "name": "cgCopy",
+          "count": "[length(variables('consumerGroups'))]"
+        },
+        "apiVersion": "2017-04-01",
+        "type": "Microsoft.EventHub/namespaces/eventhubs/consumergroups",
+        "name": "[concat(variables('ehNamespace'), '/', variables('ehName'), '/', variables('consumerGroups')[copyIndex()])]",
+        "properties": {}
+      },
+      {
+        "dependsOn": [
+          "[resourceId('Microsoft.EventHub/namespaces', variables('ehNamespace'))]"
+        ],
+        "copy": {
+          "name": "networkRuleCopy",
+          "count": "[length(parameters('subnetIds'))]"
+        },
+        "apiVersion": "2018-01-01-preview",
+        "type": "Microsoft.EventHub/namespaces/virtualnetworkrules",
+        "name": "[concat(variables('ehNamespace'), '/vnet-', copyIndex())]",
+        "properties": {
+          "virtualNetworkSubnetId": "[parameters('subnetIds')[copyIndex()]]"
+        }
+      }
+    ],
+    "outputs": {}
+  }
+
+DEPLOY
+
+  # these key-value pairs are passed into the ARM Template's `parameters` block
+  parameters = {
+    "prefix" = "${var.prefix}",
+    "messageRetentionInDays" = "${var.messageRetentionInDays}",
+    "partitionCount" = "${var.partitionCount}"
+  }
+
+  deployment_mode = "Incremental"
+}

terraform/azure/main.tf

@@ -0,0 +1,10 @@
+provider "azurerm" {
+  version = "~>1.24"
+}
+
+resource "azurerm_resource_group" "rg" {
+  name     = "${var.resource_group_name}"
+  location = "${var.location}"
+}
+
+

terraform/azure/sample.tfvars

@@ -0,0 +1,6 @@
+resource_group_name = "rg"
+location = "westus2"
+prefix = "foo"
+partitionCount = 4
+messageRetentionInDays = 1
+subnetIds = "[\"/subscriptions/<SUBSCRIPTION_ID>/resourceGroups/<RG_NAME>/providers/Microsoft.Network/virtualNetworks/databricks-vnet/subnets/<SUBNET_NAME>\",\"/subscriptions/<SUBSCRIPTION_ID>/resourceGroups/<RG_NAME>/providers/Microsoft.Network/virtualNetworks/databricks-vnet/subnets/<SUBNET_NAME>\"]"

terraform/azure/vars.tf

@@ -0,0 +1,30 @@
+# Common properties
+
+variable "resource_group_name" {
+  description = "The name of the resource group."
+}
+
+variable "location" {
+  description = "The location/region where the resources are created."
+}
+
+variable "prefix" {
+  description = "The Prefix used for resources."
+}
+
+
+# EventHub
+
+variable "subnetIds" {
+  description = "IDs of subnets. Event Hub Namespace will only accept connections from these subnets."
+  type = "string"
+}
+
+variable "partitionCount" {
+  description = "The number of partitions must be between 2 and 32. The partition count is not changeable."
+  type = "string"
+}
+variable "messageRetentionInDays" {
+  description = "The Event Hubs Standard tier allows message retention period for a maximum of seven days."
+  type = "string"
+}