I will assume that you want to install the CloudWatch agent on an EC2 instance. I took the example of sending Apache logs to CloudWatch Logs.
Ssh to your EC2 instance running Ubuntu 18.04 and running the following:
$ wget https://s3.amazonaws.com/amazoncloudwatch-agent/ubuntu/amd64/latest/amazon-cloudwatch-agent.deb $ sudo dpkg -i amazon-cloudwatch-agent.deb
NB: Do not modify any installed files, especially the ones in /opt/aws/amazon-cloudwatch-agent/etc.
You can run the configuration wizard /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-config-wizard, or edit the configuration file manually which gives you more control. The documentation is available here.
For example:
$ sudo vi /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json $ cat /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json
For example:
{
"agent": {
"metrics_collection_interval": 60, // Default metrics collection interval in seconds
"logfile": "/var/log/amazon-cloudwatch-agent.log", // Where should the CloudWatch Agent writes its logs
"debug": false // Should CloudWatch Agent run in debug mode
},
"logs": {
"logs_collected": {
"files": {
"collect_list": [
{
"file_path": "/var/log/apache2/access.log", // File where logs are written that should be forwarded to CloudWatch Logs
"log_group_name": "apache-access", // Log group to save logs to
"log_stream_name": "{instance_id}" // Log stream to save logs to
},
{
"file_path": "/var/log/apache2/error.log",
"log_group_name": "apache-error",
"log_stream_name": "{instance_id}"
}
]
}
}
},
"metrics": {
"append_dimensions": { // Dimensions to add to all metrics
"AutoScalingGroupName": "${aws:AutoScalingGroupName}",
"InstanceId": "${aws:InstanceId}"
},
"aggregation_dimensions": [["AutoScalingGroupName"]], // Dimensions on which metrics are to be aggregated
"metrics_collected": {
"collectd": { // Collect metrics through collectd; you must install collectd for this to work
"metrics_aggregation_interval": 60
},
"statsd": { // CloudAgent will act as a statsd server to allow collection of additional metrics
"metrics_aggregation_interval": 60,
"metrics_collection_interval": 10,
"service_address": ":8125"
},
"cpu": {
"measurement": [
"cpu_usage_idle",
"cpu_usage_iowait",
"cpu_usage_user",
"cpu_usage_system"
],
"totalcpu": true // Set to `false` to show each CPU, `true` to aggregate all CPUs
},
"disk": {
"measurement": [
"used_percent",
"inodes_free"
],
"resources": [
"*"
]
},
"diskio": {
"measurement": [
"io_time",
"write_bytes",
"read_bytes",
"writes",
"reads"
],
"resources": [
"*"
]
},
"mem": {
"measurement": [
"mem_used_percent"
]
},
"netstat": {
"measurement": [
"tcp_established",
"tcp_time_wait"
]
},
"swap": {
"measurement": [
"swap_used_percent"
]
}
}
}
}
To start the CloudWatch agent, run the following:
$ sudo /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
Please note this will convert the JSON config file into a TOML file which is actually used by the CloudWatch Agent; the original JSON file will be deleted.
The CloudWatch agent is integrated with systemd. It will start automatically after a reboot, and you can restart it like so:
$ sudo systemctl restart amazon-cloudwatch-agent
Restarting the agent using systemd will use the existing TOML file and will ignore any new JSON file. If you create a new configuration JSON file, you will need to use the amazon-cloudwatch-agent-ctl command.