Same ARM template that is at https://azure.microsoft.com/en-us/documentation/articles/service-bus-resource-manager-namespace-event-hub/#comment-2695399156, but includes an auth rule

ARM_EventHub_AuthRule.json

{
    "$schema": "http://schema.management.azure.com/schemas/2014-04-01-preview/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "serviceBusNamespaceName": {
            "type": "string",
            "metadata": {
                "description": "Name of the EventHub namespace"
            }
        },
        "serviceBusEventHubName": {
            "type": "string",
            "metadata": {
                "description": "Name of the Event Hub"
            }
        },
        "serviceBusConsumerGroupName": {
            "type": "string",
            "metadata": {
                "description": "Name of the Consumer Group"
            }
        },
        "serviceBusApiVersion": {
            "type": "string",
            "defaultValue": "2015-08-01",
            "metadata": {
                "description": "Service Bus ApiVersion used by the template"
            }
        },
        "eventHubAuthRule": {
            "type": "string",
            "metadata": {
                "description": "Name of the SAS Rule"
            }
        }
    },
    "variables": {
        "location": "[resourceGroup().location]",
        "ehVersion": "[parameters('serviceBusApiVersion')]",
        "defaultSASKeyName": "RootManageSharedAccessKey",
        "authRuleResourceId": "[resourceId('Microsoft.ServiceBus/namespaces/authorizationRules', parameters('serviceBusNamespaceName'), variables('defaultSASKeyName'))]"
    },
    "resources": [
        {
            "apiVersion": "[variables('ehVersion')]",
            "name": "[parameters('serviceBusNamespaceName')]",
            "type": "Microsoft.ServiceBus/Namespaces",
            "location": "[variables('location')]",
            "kind": "EventHub",
            "sku": {
                "name": "StandardSku",
                "tier": "Standard"
            },
            "resources": [
                {
                    "apiVersion": "[variables('ehVersion')]",
                    "name": "[parameters('serviceBusEventHubName')]",
                    "type": "EventHubs",
                    "dependsOn": [
                        "[concat('Microsoft.ServiceBus/namespaces/', parameters('serviceBusNamespaceName'))]"
                    ],
                    "properties": {
                        "path": "[parameters('serviceBusEventHubName')]"
                    },
                    "resources": [
                        {
                            "apiVersion": "[variables('ehVersion')]",
                            "name": "[parameters('serviceBusConsumerGroupName')]",
                            "type": "ConsumerGroups",
                            "dependsOn": [
                                "[parameters('serviceBusEventHubName')]"
                            ],
                            "properties": {}
                        },
                        {
                            "apiVersion": "[variables('ehVersion')]",
                            "name": "[parameters('eventHubAuthRule')]",
                            "type": "authorizationRules",
                            "dependsOn": [
                                "[parameters('serviceBusEventHubName')]"
                            ],
                            "properties": {
                                "Rights": ["Send"]
                            }
                        }
                    ]
                }
            ]
        }
    ],
    "outputs": {
        "NamespaceConnectionString": {
            "type": "string",
            "value": "[listkeys(variables('authRuleResourceId'), variables('ehVersion')).primaryConnectionString]"
        },
        "SharedAccessPolicyPrimaryKey": {
            "type": "string",
            "value": "[listkeys(variables('authRuleResourceId'), variables('ehVersion')).primaryKey]"
        }
    }
}

This is the authRule part:

                    {
                        "apiVersion": "[variables('ehVersion')]",
                        "name": "[parameters('eventHubAuthRule')]",
                        "type": "authorizationRules",
                        "dependsOn": [
                            "[parameters('serviceBusEventHubName')]"
                        ],
                        "properties": {
                            "Rights": ["Send"]
                        }
                    }