Boto Execute shell command on ec2 instance

Question

I am newbie to EC2 and boto. I have an EC2 running instance and I want to execute a shell command like e.g. apt-get update through boto.

I searched a lot and found a solution using user_data in the run_instances command, but what if the instance is already launched?

I don't even know if it is possible. Any clue in this reference will be a great help.

Thanks Steffen for the editing. Will remember the corrections. — vibhor, Mar 21 '13 at 18:41
Related: [How to SSH and run commands in EC2 using boto3?](https://stackoverflow.com/q/42645196/55075) — kenorb, Feb 07 '18 at 16:41

score 21 · Accepted Answer · edited Mar 20 '16 at 13:23

21

The boto.manage.cmdshell module can be used to do this. To use it, you must have the paramiko package installed. A simple example of it's use:

import boto.ec2
from boto.manage.cmdshell import sshclient_from_instance

# Connect to your region of choice
conn = boto.ec2.connect_to_region('us-west-2')

# Find the instance object related to my instanceId
instance = conn.get_all_instances(['i-12345678'])[0].instances[0]

# Create an SSH client for our instance
#    key_path is the path to the SSH private key associated with instance
#    user_name is the user to login as on the instance (e.g. ubuntu, ec2-user, etc.)
ssh_client = sshclient_from_instance(instance,
                                     '<path to SSH keyfile>',
                                     user_name='ec2-user')
# Run the command. Returns a tuple consisting of:
#    The integer status of the command
#    A string containing the output of the command
#    A string containing the stderr output of the command
status, stdout, stderr = ssh_client.run('ls -al')

That was typed from memory but I think it's correct.

You could also check out Fabric (http://docs.fabfile.org/) which has similar functionality but also has much more sophisticated features and capabilities.

edited Mar 20 '16 at 13:23

Nikolay Fominyh

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answered Mar 19 '13 at 15:42

garnaat

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Thanks for the link and a succinct comparison – Forethinker Jul 08 '13 at 18:34
If you want to use ``cmdshell`` you need to install paramiko. It is not listed as a dependency in boto because it can be difficult to install on some platforms and ``cmdshell`` is not core to boto functionality. – garnaat Jul 14 '15 at 12:28
Might also want to checkout out the EC2 RunCommand (https://aws.amazon.com/about-aws/whats-new/2015/12/ec2-run-command-now-supports-linux/) – garnaat Dec 16 '15 at 01:20
This is great, however I have one question: if I were to execute this for multiple instances, in a loop, would each `ssh_client.run('ls -al')` have to finish before the next instance ran the command? – Ryan Erwin Jun 13 '16 at 21:13
in 12th Line, what if i want to fetch ssh user from boto, is it possible to not to hardcode username? :-/ – Mr. Pundir Sep 22 '17 at 15:02

score 3 · Answer 2 · answered Mar 21 '13 at 18:31

3

I think you can use fabric for your requirements. Just check the fabric wrapper once . You can execute the command on remote server shell through fabric library.

It is very easy to use and you can integrate both boto and fabric . Together they work brilliant.

Plus the same command can executed to n number of nodes. Which I believe could be your requirements

Just check it out.

answered Mar 21 '13 at 18:31

Yes george that you were correct. It was really a great help but my problem was already solved . and i use fabric only . Anyways +1 from my side and i am accepting your answerr too – vibhor Mar 21 '13 at 18:34

score 1 · Answer 3 · answered Sep 28 '18 at 08:26

Yes, you can do this with AWS Systems manager. AWS Systems Manager Run Command allows you to remotely and securely run set of commands on EC2 as well on-premise server. Below are high-level steps to achieve this.

Attach Instance IAM role: The ec2 instance must have IAM role with policy AmazonSSMFullAccess. This role enables the instance to communicate with the Systems Manager API.

Install SSM Agent: The EC2 instance must have SSM agent installed on it. The SSM Agent process the run command requests & configure the instance as per command.

Execute command : Example usage via AWS CLI:

Execute the following command to retrieve the services running on the instance. Replace Instance-ID with ec2 instance id.

aws ssm send-command --document-name "AWS-RunShellScript" --comment "listing services" --instance-ids "Instance-ID" --parameters commands="service --status-all" --region us-west-2 --output text

More detailed information: https://www.justdocloud.com/2018/04/01/run-commands-remotely-ec2-instances/

Boto Execute shell command on ec2 instance

3 Answers3

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