aws lambda python function to reboot ec2 instances not working

Question

I have a Lambda function to reboot instances:

import boto3
region = 'us-east-1'
instances = ['i-xxxxxxxxxxxxxxxxxxxxxxxxxx']
ec2 = boto3.client('ec2', region_name=region)

def lambda_handler(event, context):
    response = ec2.reboot_instances(
        InstanceIds=[
        'i-xxxxxxxxxxxxxxxxxxxxxx',
    ],
    )
    print(response)

It just refuses to work.

The response when I trigger it:

{'ResponseMetadata': {'RequestId': '12994c92-98ab-4b62-bc10-a0e0b4881aaa', 'HTTPStatusCode': 200, 'HTTPHeaders': {'x-amzn-requestid': '12994c92-98ab-4b62-bc10-a0e0b4881aaa', 'content-type': 'text/xml;charset=UTF-8', 'content-length': '231', 'date': 'Sun, 30 Aug 2020 15:44:40 GMT', 'server': 'AmazonEC2'}, 'RetryAttempts': 0}}

The interesting part: if I change ec2.reboot_instances to ec2.start_instances then it works.

So I am trying to find out why would a reboot command be refused and a start/stop command be accepted?

Note: I included the permission in IAM to reboot instances. The instance is a linux openvpn server AMI bundle

Are you sure its not working? Check CloudTrail to see if the API action is fired — Chris Williams
So you've got 200 response can you kindly check the server started time with below command > uptime after invoking the lambda again? — Prashanna
You say that it works with start_instances() -- does that mean the instance was in a Stopped state? How are you confirming whether the reboot worked -- I don't think it appears in the system status, you would need to connect to the instance to know if it is working. — John Rotenstein
@ChrisWilliams Thanks for your reply. Created a cloudtrail log, but it doesn't log any action. — Kuitogu67

hackups33 hackups33 · Accepted Answer · 2021-01-27T01:05:24

I have used the same code as you, just one step more for you to check: Add the "RebootInstances" access right in your IAM account assigned for Lambda. If you created IAM policy following the documentation, it will be like:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "logs:CreateLogGroup",
        "logs:CreateLogStream",
        "logs:PutLogEvents"
      ],
      "Resource": "arn:aws:logs:*:*:*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:Start*",
        "ec2:Stop*",
        "ec2:Reboot*"   // <-----Add this
      ],
      "Resource": "*"
    }
  ]
}

aws lambda python function to reboot ec2 instances not working

1 Answers