Sometimes there are specific business requirements to be able to add metadata to EC2 instances. To meet such requirements, the AWS cloud controller facilitates adding custom tags to the instances upon launch.

Tags can be specified via the launch configuration schema. The launch configuration has two types of arbitrary data holders – properties and metadata. Tag data must be specified using metadata attribute.

The AWS cloud controller automatically specifies a few tags by default to new instances. Those tags are :

• identifier:The instance identifier generated by the controller
• role:The instance role
• connectionCapacity:The instance’s assumed capacity as specified in the launch configuration

Example:

{
  "launchconfig": {
    "name": "default-v2",
    "description": "This is a sample launch configuration for demonstrating the aws tagging",
    "image": "{red5pro-ami}",
    "version": "0.0.2",

  "targets": {
      "target": [
    {
      "role": "origin",
      "instanceType": "t2.micro",
      "connectionCapacity": "2000"
    },
    {
      "role": "edge",
      "instanceType": "t2.micro",
      "connectionCapacity": "2000"
    }
     ]
    },

    "properties": {
      "property": [
      ]
    },
    "metadata": {
      "meta": [
        {
          "key": "environment",
          "value": "production"
        }
      ]
    }
  }
}

Tags can then be viewed from the EC2 console, under the Tags tab. For more information refer to the AWS documentation on EC2 tags https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html.