Install SSM Agent on hybrid Linux nodes - AWS Systems Manager
Setting up private key auto rotationDeregister and reregister a managed node (Linux)Troubleshooting SSM Agent installation on non-EC2 Linux machines

Install SSM Agent on hybrid Linux nodes

This topic describes how to install AWS Systems Manager SSM Agent on non-EC2 (Amazon Elastic Compute Cloud) Linux machines in a hybrid and multicloud environment. For information about installing SSM Agent on EC2 instances for Linux, see Manually installing and uninstalling SSM Agent on EC2 instances for Linux.

Before you begin, locate the Activation Code and Activation ID that were generated during the hybrid activation process, as described in Create a hybrid activation to register nodes with Systems Manager. You specify the Code and ID in the following procedure.

To install SSM Agent on non-EC2 machines in a hybrid and multicloud environment

  1. Log on to a server or VM in your hybrid and multicloud environment.

  2. If you use an HTTP or HTTPS proxy, you must set the http_proxy or https_proxy environment variables in the current shell session. If you aren't using a proxy, you can skip this step.

    For an HTTP proxy server, enter the following commands at the command line:

    export http_proxy=http://hostname:port
export https_proxy=http://hostname:port

    For an HTTPS proxy server, enter the following commands at the command line:

    export http_proxy=http://hostname:port
export https_proxy=https://hostname:port

  3. Copy and paste one of the following command blocks into SSH. Replace the placeholder values with the Activation Code and Activation ID generated during the hybrid activation process and with the identifier of the AWS Region you want to download SSM Agent from, then press Enter.

    Important

    Note the following important details:

    • Using ssm-setup-cli for non-EC2 installations maximizes the security of your Systems Manager installation and configuration.

    • sudo isn't necessary if you're a root user.

    • Download ssm-setup-cli from the same AWS Region as where your hybrid activation was created.

    • ssm-setup-cli supports a manifest-url option that determines the source where the agent is downloaded from. Don't specify a value for this option unless required by your organization.

    • When registering instances, only use the provided download link provided for ssm-setup-cli. ssm-setup-cli shouldn’t be stored separately for future use.

    • You can use the script provided here to validate the signature of ssm-setup-cli.

    region represents the identifier for an AWS Region supported by AWS Systems Manager, such as us-east-2 for the US East (Ohio) Region. For a list of supported region values, see the Region column in Systems Manager service endpoints in the Amazon Web Services General Reference.

    Additionally, ssm-setup-cli includes the following options:

    • version - Valid values are latest and stable.

    • downgrade - Allows the SSM Agent to be downgraded to an earlier version. Specify true to install an earlier version of the agent.

    • skip-signature-validation - Skips the signature validation during the download and installation of the agent.

mkdir /tmp/ssm
curl https://amazon-ssm-region.s3.region.amazonaws.com/latest/linux_amd64/ssm-setup-cli -o /tmp/ssm/ssm-setup-cli
sudo chmod +x /tmp/ssm/ssm-setup-cli
sudo /tmp/ssm/ssm-setup-cli -register -activation-code "activation-code" -activation-id "activation-id" -region "region"
mkdir /tmp/ssm
curl https://amazon-ssm-region.s3.region.amazonaws.com/latest/linux_amd64/ssm-setup-cli -o /tmp/ssm/ssm-setup-cli
sudo chmod +x /tmp/ssm/ssm-setup-cli
sudo /tmp/ssm/ssm-setup-cli -register -activation-code "activation-code" -activation-id "activation-id" -region "region"
mkdir /tmp/ssm
curl https://amazon-ssm-region.s3.region.amazonaws.com/latest/debian_amd64/ssm-setup-cli -o /tmp/ssm/ssm-setup-cli
sudo chmod +x /tmp/ssm/ssm-setup-cli
sudo /tmp/ssm/ssm-setup-cli -register -activation-code "activation-code" -activation-id "activation-id" -region "region"

  • Using .deb packages

    mkdir /tmp/ssm
curl https://amazon-ssm-region.s3.region.amazonaws.com/latest/debian_amd64/ssm-setup-cli -o /tmp/ssm/ssm-setup-cli
sudo chmod +x /tmp/ssm/ssm-setup-cli
sudo /tmp/ssm/ssm-setup-cli -register -activation-code "activation-code" -activation-id "activation-id" -region "region"

  • Using Snap packages

    You don't need to specify a URL for the download, because the snap command automatically downloads the agent from the Snap app store at https://snapcraft.io.

    On Ubuntu Server 20.04, 18.04, and 16.04 LTS, SSM Agent installer files, including agent binaries and config files, are stored in the following directory: /snap/amazon-ssm-agent/current/. If you make changes to any configuration files in this directory, then you must copy these files from the /snap directory to the /etc/amazon/ssm/ directory. Log and library files haven't changed (/var/lib/amazon/ssm, /var/log/amazon/ssm).

    sudo snap install amazon-ssm-agent --classic
sudo systemctl stop snap.amazon-ssm-agent.amazon-ssm-agent.service
sudo /snap/amazon-ssm-agent/current/amazon-ssm-agent -register -code "activation-code" -id "activation-id" -region "region" 
sudo systemctl start snap.amazon-ssm-agent.amazon-ssm-agent.service
    Important

    The candidate channel in the Snap store contains the latest version of SSM Agent; not the stable channel. If you want to track SSM Agent version information on the candidate channel, run the following command on your Ubuntu Server 18.04 and 16.04 LTS 64-bit managed nodes.

    sudo snap switch --channel=candidate amazon-ssm-agent

The command downloads and installs SSM Agent onto the hybrid-activated machine in your hybrid and multicloud environment. The command stops SSM Agent, and then registers the machine with the Systems Manager service. The machine is now a managed node. Amazon EC2 instances configured for Systems Manager are also managed nodes. In the Systems Manager console, however, your hybrid-activated nodes are distinguished from Amazon EC2 instances with the prefix "mi-".

Continue to Install SSM Agent on hybrid Windows Server nodes.

Setting up private key auto rotation

To strengthen your security posture, you can configure AWS Systems Manager Agent (SSM Agent) to automatically rotate the private key for your hybrid and multicloud environment. You can access this feature using SSM Agent version 3.0.1031.0 or later. Turn on this feature using the following procedure.

To configure SSM Agent to rotate the private key for a hybrid and multicloud environment

  1. Navigate to /etc/amazon/ssm/ on a Linux machine or C:\Program Files\Amazon\SSM for a Windows machine.

  2. Copy the contents of amazon-ssm-agent.json.template to a new file named amazon-ssm-agent.json. Save amazon-ssm-agent.json in the same directory where amazon-ssm-agent.json.template is located.

  3. Find Profile, KeyAutoRotateDays. Enter the number of days that you want between automatic private key rotations.

  4. Restart SSM Agent.

Every time you change the configuration, restart SSM Agent.

You can customize other features of SSM Agent using the same procedure. For an up-to-date list of the available configuration properties and their default values, see Config Property Definitions.

Deregister and reregister a managed node (Linux)

You can deregister a hybrid-activated managed node by calling the DeregisterManagedInstance API operation from either the AWS CLI or Tools for Windows PowerShell. Here's an example CLI command:

aws ssm deregister-managed-instance --instance-id "mi-1234567890"

To remove the remaining registration information for the agent, remove the IdentityConsumptionOrder key in the amazon-ssm-agent.json file. Then, depending on your installation type, run one of the following commands.

On Ubuntu Server nodes where SSM Agent was installed using Snap packages:

sudo /snap/amazon-ssm-agent/current/amazon-ssm-agent -register -clear

On all other Linux installations:

amazon-ssm-agent -register -clear
Note

You can reregister an on-premises server, edge device, or VM using the same activation code and ID as long as you haven't reached the instance limit for the designated activation code and ID. You can verify the instance limit for an activation code and ID by calling the describe-activations API using the AWS CLI. After you run the command, verify that the value of RegistrationCount doesn't exceed RegistrationLimit. If it does, you must use a different activation code and ID.

To reregister a managed node on a non-EC2 Linux machine

  1. Connect to your machine.

  2. Run the following command. Be sure to replace the placeholder values with the Activation Code and Activation ID generated when you created a managed-node activation, and with the identifier of the Region you want to download the SSM Agent from.

    echo "yes" | sudo /tmp/ssm/ssm-setup-cli -register -activation-code "activation-code" -activation-id "activation-id" -region "region

Troubleshooting SSM Agent installation on non-EC2 Linux machines

Use the following information to help you troubleshoot problems installing SSM Agent on hybrid-activated Linux machines in a hybrid and multicloud environment.

You receive DeliveryTimedOut error

Problem: While configuring a machine in one AWS account as a managed node for a separate AWS account, you receive DeliveryTimedOut after running the commands to install SSM Agent on the target machine.

Solution: DeliveryTimedOut is the expected response code for this scenario. The command to install SSM Agent on the target node changes the node ID of the source node. Because the node ID has changed, the source node isn't able to reply to the target node that the command failed, completed, or timed out while executing.

Unable to load node associations

Problem: After running the install commands, you see the following error in the SSM Agent error logs:

Unable to load instance associations, unable to retrieve associations unable to retrieve associations error occurred in RequestManagedInstanceRoleToken: MachineFingerprintDoesNotMatch: Fingerprint doesn't match

You see this error when the machine ID doesn't persist after a reboot.

Solution: To solve this problem, run the following command. This command forces the machine ID to persist after a reboot.

umount /etc/machine-id
systemd-machine-id-setup