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.
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.
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.
ssh_client.run('ls -al') have to finish before the next instance ran the command?
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.
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/
