ConfigSets

ConfigSet.yml

# Definition of json configuration of AmazonCloudWatchAgent
02_config-amazon-cloudwatch-agent:
  files:
    '/opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json':
      content: !Sub |
        {
          "metrics": {
            "append_dimensions": {
              "AutoScalingGroupName": "${!aws:AutoScalingGroupName}",
              "ImageId": "${!aws:ImageId}",
              "InstanceId": "${!aws:InstanceId}",
              "InstanceType": "${!aws:InstanceType}"
            },
            "aggregation_dimensions" : [["AutoScalingGroupName"]],
            "metrics_collected": {
              "mem": {
                "measurement": [
                  "mem_used_percent"
                ]
              }
            }
          }
        }
# Invoke amazon-cloudwatch-agent-ctl to restart the AmazonCloudWatchAgent.
03_restart_amazon-cloudwatch-agent:
  commands:
    01_stop_service:
      command: /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a stop
    02_start_service:
      command: /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -c file:/opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json -s
# Cfn-hup setting, it is to monitor the change of metadata.
# When there is change in the contents of json file in the metadata section, cfn-hup will call cfn-init to restart the AmazonCloudWatchAgent.
01_setupCfnHup:
  files:
    '/etc/cfn/cfn-hup.conf':
      content: !Sub |
        [main]
        stack=${AWS::StackId}
        region=${AWS::Region}
        interval=1
      mode: '000400'
      owner: root
      group: root
    '/etc/cfn/hooks.d/amazon-cloudwatch-agent-auto-reloader.conf':
      content: !Sub |
        [cfn-auto-reloader-hook]
        triggers=post.update
        path=Resources.ASGLaunchConfiguration.Metadata.AWS::CloudFormation::Init.02_config-amazon-cloudwatch-agent
        action=/opt/aws/bin/cfn-init -v --stack ${AWS::StackId} --resource ASGLaunchConfiguration --region ${AWS::Region} --configsets UpdateEnvironment
        runas=root
      mode: '000400'
      owner: root
      group: root
    '/lib/systemd/system/cfn-hup.service':
      content: |
        [Unit]
        Description=cfn-hup daemon
        [Service]
        Type=simple
        ExecStart=/opt/aws/bin/cfn-hup
        Restart=always
        [Install]
        WantedBy=multi-user.target
  commands:
    01enable_cfn_hup:
      command: |
        systemctl enable cfn-hup.service
    02start_cfn_hup:
      command: |
        systemctl start cfn-hup.service