starting amazon ec2 instance python boto3 on cygwin

Question

I am trying to launch an amazon ec2 instance via python3 on cygwin. Normally on cygwin command line I can start instance with following command

aws ec2 start-instances --instance-ids i-03e7f6391a0f523ee

But now programming in python3 and trying to start instance via python script gives me error. Here is code

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)

I run it on cygwin

 python3 start_instance.py i-03e7f6391a0f523ee on
Traceback (most recent call last):
  File "start_instance.py", line 28, in <module>
    ec2.stop_instances(InstanceIds=[instance_id], DryRun=True)
  File "/usr/lib/python3.6/site-packages/botocore/client.py", line 314, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/usr/lib/python3.6/site-packages/botocore/client.py", line 612, in _make_api_call
    raise error_class(parsed_response, operation_name)
botocore.exceptions.ClientError: An error occurred (InvalidInstanceID.Malformed) when calling the StopInstances operation: Invalid id: "on" (expecting "i-...")

What is the mistake in my code above.

Answer 1

There was error the way I was executing the script. Rather than using it

python3 start_instance.py i-03e7f6391a0f523ee on

I should have typed

python3 start_instance.py on i-03e7f6391a0f523ee 

This won't give errors.