EC2 instance setup

Using ECS ContainerInsights?

This section may not be required for your setup. For instance, if you plan to monitor ECS containers that report the metrics with ECS ContainerInsights.

In order to use the tool a CloudWatchAgent process must be running on the EC2 instance to be monitored.

Please refer to this page to learn how to install and start the CloudWatchAgent on an EC2 instance.

Configuration

CloudWatchAgent is a powerful tool and can be configured to report variety of metrics.

Here is an example of the configuration file:

{
  "agent": {
    "metrics_collection_interval": 10
  },
  "metrics": {
    "namespace": "ExampleNamespace",
    "metrics_collected": {
      "mem": {
        "measurement": ["mem_used", "mem_cached", "mem_total"],
        "metrics_collection_interval": 1
      }
    },
    "append_dimensions": {
      "InstanceId": "${aws:InstanceId}"
    }
  }
}

The above configuration file is used to colect 3 memory metrics every second:

• mem_used
• mem_cached
• mem_total

EC2 userdata

The tool can be configured to be launched automatically by the EC2 instance userdata. Here are the steps to configure the tool to be launched automatically:

1. Download CloudWatchAgent appropriate for your EC2 instance type; learn more here.
2. Install CloudWatchAgent on the EC2 instance.
3. Create/copy a CloudWatchAgent configuration file.
4. Start the CloudWatchAgent service pointing to the created configuration file.

For a Debian EC2 instance, the steps can be achieved by executing the following commands:

#!/bin/bash
CLOUDWATCH_CFG_SRC=<path-in-repo>/config.json
CLOUDWATCH_CFG_FILE=/opt/aws/amazon-cloudwatch-agent/bin/config.json

wget https://s3.amazonaws.com/amazoncloudwatch-agent/debian/amd64/latest/amazon-cloudwatch-agent.deb
dpkg -i -E ./amazon-cloudwatch-agent.deb
cp $CLOUDWATCH_CFG_SRC $CLOUDWATCH_CFG_FILE
/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c file:$CLOUDWATCH_CFG_FILE