Remotely Run Commands on an Amazon EC2 Instance

With Amazon Systems Manager

In this hands-on tutorial, you will learn how to use Amazon Systems Manager to remotely run commands on your Amazon EC2 instances. Systems Manager is a Management Tool that enables you gain operational insights and take action on Amazon Web Services resources safely and at scale. Using the run command, one of the automation features of Systems Manager, you can simplify management tasks by eliminating the need to use bastion hosts, SSH, or remote PowerShell.

In our example scenario, as a System Administrator, you need to update the packages on your Amazon EC2 instances. To complicate this normally simple admin task, your security team does not allow you to direct access production servers via SSH or allow you use bastion hosts. Fortunately, you can use Systems Manager to remotely run commands, like update packages, on your Amazon EC2 instances.

To solve this challenging scenario, you will create an Identity and Access Management (IAM) role, enable an agent on your instance that communicates with Systems Manager, then follow best practices by running the AWS-UpdateSSMAgent document to upgrade your Systems Manager Agent, and finally use Systems Manager to run a command on your instance.

Open the Amazon Web Services Management Console, so you can keep this step-by-step guide open. When the screen loads, enter your user name and password to get started.  

Manage Your Amazon Web Services Resources


Step 1. Create an Identity and Access Management (IAM) role

In this step, you will create an IAM role that will be used to give Systems Manager permission to perform actions on your instances.


a.  Click here, open the IAM console.

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b.  In the left navigation pane, choose Roles, and then choose Create role.

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c.  On the Select type of trusted entity page, under Amazon Web Services Service, choose Amazon EC2, and then choose Next: Permissions.

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d.  On the Attached permissions policy page, in the search bar type AmazonEC2RoleforSSM then from the policy list select AmazonEC2RoleforSSM, and then choose Next: Review.

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e.  On the Review page, in the Role name box type in EnablesEC2ToAccessSystemsManagerRole. In the Role description box type in Enables an EC2 instance to access Systems Manager. Choose Create role.

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Step 2. Create an Amazon EC2 instance

In this step you will you will create an Amazon EC2 instance using the EnablesEC2ToAccessSystemsManagerRole role. This will allow the Amazon EC2 instance to be managed by Systems Manager.


a.  Open the Amazon EC2 console. From the Amazon EC2 console select your preferred region. Systems Manager is supported in all Amazon Web Services Regions. Now choose Launch Instance

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b.  Select the Amazon Linux AMI. Make sure you select Amazon Linux base AMI dated 2017.09 or later which includes the Systems Manager Agent by default. You can also install the Systems Manger Agent on your own Windows or Linux system.

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c.  On the Step 2: Choose an Instance Type page, choose the t2.micro instance type and then click Next: Configure Instance Details.

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d.  On the Step 3: Configure Instance Details page, In the IAM role dropdown choose the EnablesEC2ToAccessSystemsManagerRole role you created earlier. Leave everything else as default. Choose Review and Launch.

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e.  On the Step 7: Review Instance Launch page, choose Launch to launch your instance.

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f.  Next the Select an existing keypair or create a new key pair dialog will appear. You will not need a keypair to use Systems Manager to remotely run commands. From the Choose an existing pair dropdown choose Proceed without a key pair and tick the I acknowledge that… checkbox.

Next select Launch Instance.

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Step 3. Update the Systems Manager Agent

Now that you have an Amazon EC2 instance running the Systems Manager agent, you can automate administration tasks and manage the instance. In this step, you run a pre-packaged command, called a document, that will upgrade the agent. It is best practice to update the System Manager Agent when you create a new instance.


a.  In the top menu click on Services. Then, under Management Tools, select Systems Manager to open the Systems Manager console.

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b.  Under the Shared Resources section on the left navigation bar, choose Managed Instances.

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c.  On the Managed instances page, in the Actions drop down select Run Command.

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d.  On the Run a command page, click in the search bar and select, Document name prefix, then click on Equal, then type in AWS-UpdateSSMAgent.

Now click on the radio button on the left of AWS-UpdateSSMAgent. This document will upgrade Systems Management agent on the instance.

Scroll down to the Targets panel and click the check box next to your managed Amazon EC2 instance.

Finally, scroll down and select Run.

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e.  Next you will see page documenting your running command then and overall success in green. Congrats, you have just run your first remote command using Systems Manager.

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Step 4. Run a Remote Shell Script

Now that your Amazon EC2 instance has the latest Systems Manager Agent, you can upgrade the packages on the Amazon EC2 instance. In this step, you will run a shell script through Run Command.


a.  From the Systems Management console, in the left nav under Shared Resources select Managed instances. Then in the Actions menu, select the Run Command menu item. 

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b.  On the Run a command page, click in the search bar and select, Document name prefix, then click on Equal, then type in AWS-RunShellScript.

Now click on the radio button on the left of AWS-RunShellScript. This document will upgrade Systems Management agent on the instance.

Scroll down to the Targets panel and click the check box next to your managed Amazon EC2 instance.

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c.  Scroll down to the Command Parameters panel and insert the following command in the Commands text box:

sudo yum update -y

Finally, scroll down and select Run.

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d.  While your script is running remotely on the managed Amazon EC2 instance, the Overall status will be In Progress. Soon the Overall status will turn to Success. When it does, scroll down to the Targets and outputs panel and click on the Instance ID of your instance. Your Instance ID will be different than the one pictured.

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e.  From the Output on: i-XX page click on the header of the Step 1 - Output panel to view the output of the update command from the instance.

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Step 5. Terminate Your Resources

In this step you will terminate your Systems Manager and Amazon EC2 related resources. Important: Terminating resources that are not actively being used reduces costs and is a best practice. Not terminating your resources can result in a charge.


a.  Open the Amazon EC2 console and from the left nav under the Instances heading select Instances.

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b.  Select your instance's checkbox and click Actions, then Instance State, then Terminate. This will terminate your instance completely.

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Congratulations!

Congratulations, you have successfully created a managed instance and remotely run a command using Amazon Systems Manager. You first set up the correct permissions through IAM. Next you launched an Amazon Linux instance that was preinstalled with the Systems Manager agent. Finally, you used Run Command to update the agent and remotely perform a yum update.

Systems Manager is a good choice when you need to view operation data for groups of resources, automate operational actions, understand and control the current state of your resources, manage hybrid environments, and maintain security and compliance.