Cloudwatch log_stream_name {instance_id} is sending over hostname instead

Hi,

I am trying to set up CloudWatch log streaming for custom logs for a multi-container application running on elastic beanstalk.

The issue that I am facing is when the log stream is sent over from an instance instead of being the instance id such as i-123456789a1234567 it is sending the hostname which is like ip-00-0-000-000.eu-west-1.compute.internal

Following the documentation here https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/AWSHowTo.cloudwatchlogs.html#AWSHowTo.cloudwatchlogs.loggroups under Custom log file streaming

and the following configuration block (found on the elastic beanstalk samples - https://github.com/awsdocs/elastic-beanstalk-samples/blob/master/configuration-files/aws-provided/instance-configuration/logs-streamtocloudwatch-linux.config)

packages:
  yum:
    awslogs: []

files:
  "/etc/awslogs/awscli.conf" :
    mode: "000600"
    owner: root
    group: root
    content: |
      [plugins]
      cwlogs = cwlogs
      [default]
      region = `{"Ref":"AWS::Region"}`

  "/etc/awslogs/awslogs.conf" :
    mode: "000600"
    owner: root
    group: root
    content: |
      [general]
      state_file = /var/lib/awslogs/agent-state

  "/etc/awslogs/config/logs.conf" :
    mode: "000600"
    owner: root
    group: root
    content: |
      [/var/log/messages]
      log_group_name = `{"Fn::Join":["/", ["/aws/elasticbeanstalk", { "Ref":"AWSEBEnvironmentName" }, "var/log/messages"]]}`
      log_stream_name = {instance_id}
      file = /var/log/messages

      [/var/log/dmesg]
      log_group_name = `{"Fn::Join":["/", ["/aws/elasticbeanstalk", { "Ref":"AWSEBEnvironmentName" }, "var/log/dmesg"]]}`
      log_stream_name = {instance_id}
      file = /var/log/dmesg

commands:
  "01":
    command: systemctl enable awslogsd.service
  "02":
    command: systemctl restart awslogsd

Any ideas on how I can get this to stream through the reference of the EC2 instance rather than the hostname?

Thanks