Managing Amazon EC2 instances#

This Python example shows you how to:

  • Get basic information about your Amazon EC2 instances

  • Start and stop detailed monitoring of an Amazon EC2 instance

  • Start and stop an Amazon EC2 instance

  • Reboot an Amazon EC2 instance

The scenario#

In this example, Python code is used perform several basic instance management operations. The code uses the AWS SDK for Python to manage the instances by using these methods of the EC2 client class:

For more information about the lifecycle of Amazon EC2 instances, see Instance Lifecycle in the Amazon EC2 User Guide for Linux Instances or Instance Lifecycle in the Amazon EC2 User Guide for Windows Instances.

All the example code for the Amazon Web Services (AWS) SDK for Python is available here on GitHub.

Prerequisite tasks#

To set up and run this example, you must first configure your AWS credentials, as described in Quickstart.

Describe instances#

An EC2 instance is a virtual server in Amazon’s Elastic Compute Cloud (EC2) for running applications on the Amazon Web Services (AWS) infrastructure.

The example below shows how to:

All the example code for the Amazon Web Services (AWS) SDK for Python is available here on GitHub.

Example#

import boto3

ec2 = boto3.client('ec2')
response = ec2.describe_instances()
print(response)

Monitor and unmonitor instances#

Enable or disable detailed monitoring for a running instance. If detailed monitoring is not enabled, basic monitoring is enabled. For more information, see Monitoring Your Instances and Volumes in the Amazon Elastic Compute Cloud User Guide.

The example below shows how to:

Example#

import sys
import boto3


ec2 = boto3.client('ec2')
if sys.argv[1] == 'ON':
    response = ec2.monitor_instances(InstanceIds=['INSTANCE_ID'])
else:
    response = ec2.unmonitor_instances(InstanceIds=['INSTANCE_ID'])
print(response)

Start and stop instances#

Instances that use Amazon EBS volumes as their root devices can be quickly stopped and started. When an instance is stopped, the compute resources are released and you are not billed for hourly instance usage. However, your root partition Amazon EBS volume remains, continues to persist your data, and you are charged for Amazon EBS volume usage. You can restart your instance at any time. Each time you transition an instance from stopped to started, Amazon EC2 charges a full instance hour, even if transitions happen multiple times within a single hour.

The example below shows how to:

  • Start an Amazon EBS-backed AMI that you’ve previously stopped using start_instances.

  • Stop an Amazon EBS-backed instance using stop_instances.

Example#

import sys
import boto3
from botocore.exceptions import ClientError

instance_id = sys.argv[2]
action = sys.argv[1].upper()

ec2 = boto3.client('ec2')


if action == 'ON':
    # Do a dryrun first to verify permissions
    try:
        ec2.start_instances(InstanceIds=[instance_id], DryRun=True)
    except ClientError as e:
        if 'DryRunOperation' not in str(e):
            raise

    # Dry run succeeded, run start_instances without dryrun
    try:
        response = ec2.start_instances(InstanceIds=[instance_id], DryRun=False)
        print(response)
    except ClientError as e:
        print(e)
else:
    # Do a dryrun first to verify permissions
    try:
        ec2.stop_instances(InstanceIds=[instance_id], DryRun=True)
    except ClientError as e:
        if 'DryRunOperation' not in str(e):
            raise

    # Dry run succeeded, call stop_instances without dryrun
    try:
        response = ec2.stop_instances(InstanceIds=[instance_id], DryRun=False)
        print(response)
    except ClientError as e:
        print(e)

Reboot instances#

Request a reboot of one or more instances. This operation is asynchronous; it only queues a request to reboot the specified instances. The operation succeeds if the instances are valid and belong to you. Requests to reboot terminated instances are ignored.

The example below shows how to:

Example#

import boto3
from botocore.exceptions import ClientError


ec2 = boto3.client('ec2')

try:
    ec2.reboot_instances(InstanceIds=['INSTANCE_ID'], DryRun=True)
except ClientError as e:
    if 'DryRunOperation' not in str(e):
        print("You don't have permission to reboot instances.")
        raise

try:
    response = ec2.reboot_instances(InstanceIds=['INSTANCE_ID'], DryRun=False)
    print('Success', response)
except ClientError as e:
    print('Error', e)