

There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Run a shell script to install libraries on Amazon EMR instances using an AWS SDK
<a name="emr_example_emr_Usage_InstallLibrariesWithSsm_section"></a>

The following code example shows how to use AWS Systems Manager to run a shell script on Amazon EMR instances that installs additional libraries. This way, you can automate instance management instead of running commands manually through an SSH connection.

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#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/emr#code-examples). 

```
import argparse
import time
import boto3


def install_libraries_on_core_nodes(cluster_id, script_path, emr_client, ssm_client):
    """
    Copies and runs a shell script on the core nodes in the cluster.

    :param cluster_id: The ID of the cluster.
    :param script_path: The path to the script, typically an Amazon S3 object URL.
    :param emr_client: The Boto3 Amazon EMR client.
    :param ssm_client: The Boto3 AWS Systems Manager client.
    """
    core_nodes = emr_client.list_instances(
        ClusterId=cluster_id, InstanceGroupTypes=["CORE"]
    )["Instances"]
    core_instance_ids = [node["Ec2InstanceId"] for node in core_nodes]
    print(f"Found core instances: {core_instance_ids}.")

    commands = [
        # Copy the shell script from Amazon S3 to each node instance.
        f"aws s3 cp {script_path} /home/hadoop",
        # Run the shell script to install libraries on each node instance.
        "bash /home/hadoop/install_libraries.sh",
    ]
    for command in commands:
        print(f"Sending '{command}' to core instances...")
        command_id = ssm_client.send_command(
            InstanceIds=core_instance_ids,
            DocumentName="AWS-RunShellScript",
            Parameters={"commands": [command]},
            TimeoutSeconds=3600,
        )["Command"]["CommandId"]
        while True:
            # Verify the previous step succeeded before running the next step.
            cmd_result = ssm_client.list_commands(CommandId=command_id)["Commands"][0]
            if cmd_result["StatusDetails"] == "Success":
                print(f"Command succeeded.")
                break
            elif cmd_result["StatusDetails"] in ["Pending", "InProgress"]:
                print(f"Command status is {cmd_result['StatusDetails']}, waiting...")
                time.sleep(10)
            else:
                print(f"Command status is {cmd_result['StatusDetails']}, quitting.")
                raise RuntimeError(
                    f"Command {command} failed to run. "
                    f"Details: {cmd_result['StatusDetails']}"
                )


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("cluster_id", help="The ID of the cluster.")
    parser.add_argument("script_path", help="The path to the script in Amazon S3.")
    args = parser.parse_args()

    emr_client = boto3.client("emr")
    ssm_client = boto3.client("ssm")

    install_libraries_on_core_nodes(
        args.cluster_id, args.script_path, emr_client, ssm_client
    )


if __name__ == "__main__":
    main()
```
+  For API details, see [ListInstances](https://docs.aws.amazon.com/goto/boto3/elasticmapreduce-2009-03-31/ListInstances) in *AWS SDK for Python (Boto3) API Reference*. 

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