EventBridge:Use Terraform to manage event buses

Before you start

• Make sure that the following services are activated:

  • EventBridge is activated. For more information, see Activate EventBridge and grant permissions to a RAM user.

  • Simple Message Queue (SMQ, formerly MNS) is activated. For more information, see Activate SMQ and authorize RAM users to access SMQ.

• We recommend that you use a RAM user that has the minimum required permissions to perform the operations in this topic. This reduces the risk of leaking the AccessKey pair of your Alibaba Cloud account. For more information, see Create a RAM user and Grant permissions to a RAM user. In this topic, the following policy is attached to the RAM user:

  {
    "Version": "1",
    "Statement": [
      {
        "Effect": "Allow",
        "Action": "mns:*",
        "Resource": "*"
      },
      {
        "Effect": "Allow",
        "Action": [
          "eventbridge:GetEventBus",
          "eventbridge:ListEventBuses",
          "eventbridge:CreateEventBus",
          "eventbridge:DeleteEventBus",
          "eventbridge:UpdateEventBus",
          "eventbridge:ListApiDestinations",
          "eventbridge:ListUserDefinedEventSources",
          "eventbridge:CreateEventSource",
          "eventbridge:DeleteEventSource",
          "eventbridge:UpdateEventSource",
          "eventbridge:ListPartnerEventSources",
          "eventbridge:GetRule",
          "eventbridge:ListRules",
          "eventbridge:CreateRule",
          "eventbridge:DeleteRule",
          "eventbridge:EnableRule",
          "eventbridge:UpdateRule",
          "eventbridge:ListConnections",
          "eventbridge:CreateConnection",
          "eventbridge:DeleteConnection",
          "eventbridge:UpdateConnection",
          "eventbridge:GetConnection",
          "eventbridge:GetApiDestination",
          "eventbridge:CreateApiDestination",
          "eventbridge:DeleteApiDestination",
          "eventbridge:UpdateApiDestination"
        ],
        "Resource": "*"
      }
    ]
  }

• The runtime environment for Terraform is prepared by using one of the following methods:

  • Use Terraform in Terraform Explorer: Alibaba Cloud provides an online runtime environment for Terraform. You can log on to the environment and use Terraform without needing to install it. Suitable for scenarios where you need to use and debug Terraform in a low-cost, efficient, and convenient manner.

  • Use Terraform in Cloud Shell: Cloud Shell is preinstalled with Terraform and configured with your identity credentials. You can run Terraform commands in Cloud Shell. Suitable for scenarios where you need to use and access Terraform in a low-cost, efficient, and convenient manner.

  • Install and configure Terraform on your on-premises machine: Suitable for scenarios where network connections are unstable or a custom development environment is needed.

Resources

Step 1: Create an event bus and an event source

1. Create a working directory that contains a configuration file named main.tf. Then, copy the following code to the main.tf configuration file. The code is used to create an event bus and an SMQ queue and specify the SMQ queue as the event source.

   variable "region" {
     default = "cn-shanghai"
   }
   
   provider "alicloud" {
     region = var.region
   }
   
   variable "api_key_name"{
     default = "<The username of the API key that you use for authentication>"
   }
   
   
   variable "api_key_value"{
     default = "<The value of the API key that you use for authentication>"
   }
   
   # The URL of the API destination.
   variable "endpoint"{
     default = "http://xxxx:8080/putEventsByAPiKey"
   }
   
   data "alicloud_account" "default" {
   }
   
   resource "random_integer" "default" {
     min = 10000
     max = 99999
   }
   
   # The custom event bus.
   resource "alicloud_event_bridge_event_bus" "example" {
     event_bus_name = "event_bus_name_${random_integer.default.result}"
   }
   
   # The SMQ queue. The queue is used as the event source.
   resource "alicloud_mns_queue" "source" {
     name = "queue-name-source-${random_integer.default.result}"
   }
   
   # The custom event source.
   resource "alicloud_event_bridge_event_source" "default" {
     event_bus_name         = alicloud_event_bridge_event_bus.example.event_bus_name
     event_source_name      = "event_source_name_${random_integer.default.result}"
     description            = "description_${random_integer.default.result}"
     linked_external_source = true
     external_source_type   = "MNS"
     external_source_config = {
       QueueName = alicloud_mns_queue.source.name
     }
   }

2. Run the following command to initialize the Terraform runtime environment:

   terraform init

   If the following information is returned, Terraform is initialized.

   Terraform has been successfully initialized!
   
   You may now begin working with Terraform. Try running "terraform plan" to see
   any changes that are required for your infrastructure. All Terraform commands
   should now work.
   
   If you ever set or change modules or backend configuration for Terraform,
   rerun this command to reinitialize your working directory. If you forget, other
   commands will detect it and remind you to do so if necessary.

3. Run the following command to start code execution:

   terraform apply

   During the code execution, enter yes as prompted and press the Enter key. Wait until the command is complete. If the following information is returned, the code is successfully run.

   You can apply this plan to save these new output values to the Terraform state, without changing any real infrastructure.
   
   Do you want to perform these actions?
     Terraform will perform the actions described above.
     Only 'yes' will be accepted to approve.
   
     Enter a value: yes
   
   
   Apply complete!  Resources: 4 added, 0 changed, 0 destroyed.

4. Verify the result.

   Use the terraform show command

   Run the following command in the working directory to query the details of the resources that you created by using Terraform:

   terraform show

   

   Use the EventBridge console

   1. Log on to the EventBridge console and go to the Event Buses page. In the top navigation bar, select the region where the custom event bus that you created resides. In this example, China (Shanghai) is selected. Then, in the event bus list, view the custom event bus that you created.

      

   2. On the Event Buses page, click the name of the custom event bus that you created. In the left-side navigation pane of the event bus details page, click to view the event source that you created.

      

Step 2: Create a connection and an API destination

1. In the main.tf file, add the following content:

   # The connection.
   resource "alicloud_event_bridge_connection" "defaultConnection" {
     connection_name = "connection_name_${random_integer.default.result}"
     description     = "description_alicloud_event_bridge_connection_${random_integer.default.result}"
     network_parameters {
       network_type      = "PublicNetwork"
     }
     auth_parameters {
       authorization_type = "API_KEY_AUTH"
       api_key_auth_parameters {
         api_key_name  = var.api_key_name
         api_key_value = var.api_key_value
       }
     }
   }
   
   # The API destination.
   resource "alicloud_event_bridge_api_destination" "default" {
     description = "description_alicloud_event_bridge_api_destinationn_${random_integer.default.result}"
     http_api_parameters {
       endpoint = var.endpoint
       method   = "POST"
     }
     api_destination_name = "api_destination_name_${random_integer.default.result}"
     connection_name = alicloud_event_bridge_connection.defaultConnection.connection_name
   }

2. Create an execution plan and preview the changes.

   terraform plan

3. Run the following command to start code execution:

   terraform apply

   During the code execution, enter yes as prompted and press the Enter key. Wait until the command is complete. If the following information is returned, the code is successfully run.

   Apply complete!  Resources: 2 added, 0 changed, 0 destroyed.

4. Verify the result.

   Use the terraform show command

   Run the following command in the working directory to query the details of the resources that you created by using Terraform:

   terraform show

   

   Use the EventBridge console

   1. Log on to the EventBridge console. In the left-side navigation pane, choose Integration Center > API Destination. In the top navigation bar, select the region where the connection that you created resides. In this example, China (Shanghai) is selected. Then, click the Connection tab to view the connection that you created.

      

   2. Click the API Destination tab to view the API destination that you created.

      

Step 3: Create an event rule

1. In the main.tf file, add the following content:

   # The event rule.
   resource "alicloud_event_bridge_rule" "default" {
     event_bus_name = alicloud_event_bridge_event_bus.example.event_bus_name
     rule_name      = "rule_name_${random_integer.default.result}"
     description    = "description_${random_integer.default.result}"
     filter_pattern = "{\n \"source\": [\n \"tf-test-api-key\"\n ]\n}"
     targets {
       target_id = "tf_example_${random_integer.default.result}"
       endpoint  = "acs:api-destination:${var.region}:${data.alicloud_account.default.id}:name/${alicloud_event_bridge_api_destination.default.api_destination_name}"
       type      = "acs.api.destination"
       param_list {
         resource_key = "Name"
         form         = "CONSTANT"
         value        = "terraform-api_destination-name-api-key"
       }
       param_list {
         resource_key = "QueryStringParameters"
         form         = "TEMPLATE"
         value        = "{\"queryKey1\":\"id\",\"queryValue1\":\"$.data.name\"}"
         # ${} is used to specify variables in EventBridge, and $${} is used to specify variables in Terraform files. 
         template     = "{\"$${queryKey1}\":\"$${queryValue1}\"}"
       }
     }
   }

2. Create an execution plan and preview the changes.

   terraform plan

3. Run the following command to start code execution:

   terraform apply

   During the code execution, enter yes as prompted and press the Enter key. Wait until the command is complete. If the following information is returned, the code is successfully run.

   Apply complete!  Resources: 1 added, 0 changed, 0 destroyed.

4. Verify the result.

   Use the terraform show command

   Run the following command in the working directory to query the details of the resource that you created by using Terraform:

   terraform show

   

   Use the EventBridge console

   1. Log on to the EventBridge console and go to the Event Buses page. In the top navigation bar, select the region where the event rule that you created resides. In this example, China (Shanghai) is selected. Then, in the event bus list, find the custom event bus that you created and click Event Rule in the Actions column to view the event rule that you created.

      

Release resources

If you no longer require the preceding resources that are created or managed by using Terraform, run the following command to release the resources. For more information about the terraform destroy command, see Common commands.

terraform destroy

Complete sample code

variable "region" {
  default = "cn-shanghai"
}

provider "alicloud" {
  region = var.region
}

variable "api_key_name"{
  default = "<The username of the API key that you use for authentication>"
}


variable "api_key_value"{
  default = "<The value of the API key that you use for authentication>"
}

# The URL of the API destination.
variable "endpoint"{
  default = "http://xxxx:8080/putEventsByAPiKey"
}

data "alicloud_account" "default" {
}

resource "random_integer" "default" {
  min = 10000
  max = 99999
}

# The custom event bus.
resource "alicloud_event_bridge_event_bus" "example" {
  event_bus_name = "event_bus_name_${random_integer.default.result}"
}

# The SMQ queue. The queue is used as the event source.
resource "alicloud_mns_queue" "source" {
  name = "queue-name-source-${random_integer.default.result}"
}

# The custom event source.
resource "alicloud_event_bridge_event_source" "default" {
  event_bus_name         = alicloud_event_bridge_event_bus.example.event_bus_name
  event_source_name      = "event_source_name_${random_integer.default.result}"
  description            = "description_${random_integer.default.result}"
  linked_external_source = true
  external_source_type   = "MNS"
  external_source_config = {
    QueueName = alicloud_mns_queue.source.name
  }
}

# The connection.
resource "alicloud_event_bridge_connection" "defaultConnection" {
  connection_name = "connection_name_${random_integer.default.result}"
  description     = "description_alicloud_event_bridge_connection_${random_integer.default.result}"
  network_parameters {
    network_type      = "PublicNetwork"
  }
  auth_parameters {
    authorization_type = "API_KEY_AUTH"
    api_key_auth_parameters {
      api_key_name  = var.api_key_name
      api_key_value = var.api_key_value
    }
  }
}

# The API destination.
resource "alicloud_event_bridge_api_destination" "default" {
  description = "description_alicloud_event_bridge_api_destinationn_${random_integer.default.result}"
  http_api_parameters {
    endpoint = var.endpoint
    method   = "POST"
  }
  api_destination_name = "api_destination_name_${random_integer.default.result}"
  connection_name = alicloud_event_bridge_connection.defaultConnection.connection_name
}

# The event rule
resource "alicloud_event_bridge_rule" "default" {
  event_bus_name = alicloud_event_bridge_event_bus.example.event_bus_name
  rule_name      = "rule_name_${random_integer.default.result}"
  description    = "description_${random_integer.default.result}"
  filter_pattern = "{\n \"source\": [\n \"tf-test-api-key\"\n ]\n}"
  targets {
    target_id = "tf_example_${random_integer.default.result}"
    endpoint  = "acs:api-destination:${var.region}:${data.alicloud_account.default.id}:name/${alicloud_event_bridge_api_destination.default.api_destination_name}"
    type      = "acs.api.destination"
    param_list {
      resource_key = "Name"
      form         = "CONSTANT"
      value        = "terraform-api_destination-name-api-key"
    }
    param_list {
      resource_key = "QueryStringParameters"
      form         = "TEMPLATE"
      value        = "{\"queryKey1\":\"id\",\"queryValue1\":\"$.data.name\"}"
      # ${} is used to specify variables in EventBridge, and $${} is used to specify variables in Terraform files. 
      template     = "{\"$${queryKey1}\":\"$${queryValue1}\"}"
    }
  }
}

To view more examples, visit the Event_Bridge folder in GitHub.