Patch Management

Systems Manager: Patch Manager

AWS Systems Manager Patch Manager automates the process of patching managed instances with security related updates.

NoteFor Linux-based instances, you can also install patches for non-security updates.

You can patch fleets of Amazon EC2 instances or your on-premises servers and virtual machines (VMs) by operating system type. This includes supported versions of Windows, Ubuntu Server, Red Hat Enterprise Linux (RHEL), SUSE Linux Enterprise Server (SLES), and Amazon Linux. You can scan instances to see only a report of missing patches, or you can scan and automatically install all missing patches. You can target instances individually or in large groups by using Amazon EC2 tags.

Warning

  • AWS does not test patches for Windows or Linux before making them available in Patch Manager .
  • If any updates are installed by Patch Manager the patched instance is rebooted.
  • Always test patches thoroughly before deploying to production environments.

Patch Baselines

Patch Manager uses patch baselines, which include rules for auto-approving patches within days of their release, as well as a list of approved and rejected patches. Later in this lab we will schedule patching to occur on a regular basis using a Systems Manager Maintenance Window task. Patch Manager integrates with AWS Identity and Access Management (IAM), AWS CloudTrail, and Amazon CloudWatch Events to provide a secure patching experience that includes event notifications and the ability to audit usage.

WarningThe operating systems supported by Patch Manager may vary from those supported by the SSM Agent.

5.1 Create a Patch Baseline

  1. Under Instances and Nodes in the AWS Systems Manager navigation bar, choose Patch Manager.
  2. Click the View predefined patch baselines link under the Configure patching button on the upper right.
  3. Choose Create patch baseline.
  4. On the Create patch baseline page in the Provide patch baseline details section:
    1. Enter a Name for your custom patch baseline, such as AmazonLinuxSecAndNonSecBaseline.
    2. Optionally enter a description, such as Amazon Linux patch baseline including security and non-security patches.
    3. Select Amazon Linux from the list.
  5. In the Approval rules section:
    1. Examine the options in the lists and ensure that Product, Classification, and Severity have values of All.
    2. Leave the Auto approval delay at its default of 0 days.
    3. Change the value of Compliance reporting - optional to Critical.
    4. Choose Add another rule.
    5. In the new rule, change the value of Compliance reporting - optional to Medium.
    6. Check the box under Include non-security updates to include all Amazon Linux updates when patching.

If an approved patch is reported as missing, the option you choose in Compliance reporting, such as Critical or Medium, determines the severity of the compliance violation reported in System Manager Compliance.

  1. In the Patch exceptions section in the Rejected patches - optional text box, enter system-release.* This will reject patches to new Amazon Linux releases that may advance you beyond the Patch Manager supported operating systems prior to your testing new releases.
  2. For Linux operating systems, you can optionally define an alternative patch source repository. Choose the X in the Patch sources area to remove the empty patch source definition.
  3. Choose Create patch baseline and you will go to the Patch Baselines page where the AWS provided default patch baselines, and your custom baseline, are displayed.

Patch Groups

A patch group is an optional method to organize instances for patching. For example, you can create patch groups for different operating systems (Linux or Windows), different environments (Development, Test, and Production), or different server functions (web servers, file servers, databases). Patch groups can help you avoid deploying patches to the wrong set of instances. They can also help you avoid deploying patches before they have been adequately tested.

You create a patch group by using Amazon EC2 tags. Unlike other tagging scenarios across Systems Manager, a patch group must be defined with the tag key: Patch Group (tag keys are case sensitive). You can specify any value (for example, web servers) but the key must be Patch Group.

NoteAn instance can only be in one patch group.

After you create a patch group and tag instances, you can register the patch group with a patch baseline. By registering the patch group with a patch baseline, you ensure that the correct patches are installed during the patching execution. When the system applies a patch baseline to an instance, the service checks if a patch group is defined for the instance.

  • If the instance is assigned to a patch group, the system checks to see which patch baseline is registered to that group.
  • If a patch baseline is found for that group, the system applies that patch baseline.
  • If an instance isn’t assigned to a patch group, the system automatically uses the currently configured default patch baseline.

5.2 Assign a Patch Group

  1. Choose the Baseline ID of your newly created baseline to enter the details screen.
  2. Choose Actions in the top right of the window and select Modify patch groups.
  3. In the Modify patch groups window under Patch groups, enter Critical, choose Add, and then choose Close to be returned to the Patch Baseline details screen.

AWS-RunPatchBaseline

AWS-RunPatchBaseline is a command document that enables you to control patch approvals using patch baselines. It reports patch compliance information that you can view using the Systems Manager Compliance tools. For example,you can view which instances are missing patches and what those patches are.

For Linux operating systems, compliance information is provided for patches from both the default source repository configured on an instance and from any alternative source repositories you specify in a custom patch baseline. AWS-RunPatchBaseline supports both Windows and Linux operating systems.

AWS Systems Manager: Document

An AWS Systems Manager document defines the actions that Systems Manager performs on your managed instances. Systems Manager includes many pre-configured documents that you can use by specifying parameters at runtime, including ‘AWS-RunPatchBaseline’. These documents use JavaScript Object Notation (JSON) or YAML, and they include steps and parameters that you specify.

All AWS provided Automation and Run Command documents can be viewed in AWS Systems Manager Documents. You can create your own documents or launch existing scripts using provided documents to implement custom operations as code activities.

5.3 Examine AWS-RunPatchBaseline in Documents

To examine AWS-RunPatchBaseline in Documents:

  1. In the AWS Systems Manager navigation bar under Shared Resources, choose Documents.
  2. Click in the search box, select Document name prefix, and then Equal.
  3. Type AWS-Run into the text field and press Enter on your keyboard to start the search.
  4. Select AWS-RunPatchBaseline and choose View details.
  5. Review the content of each tab in the details page of the document.

AWS Systems Manager: Run Command

AWS Systems Manager Run Command lets you remotely and securely manage the configuration of your managed instances. Run Command enables you to automate common administrative tasks and perform ad hoc configuration changes at scale. You can use Run Command from the AWS Management Console, the AWS Command Line Interface, AWS Tools for Windows PowerShell, or the AWS SDKs.

5.4 Scan Your Instances with AWS-RunPatchBaseline via Run Command

  1. Under Instances and Nodes in the AWS Systems Manager navigation bar, choose Run Command. In the Run Command dashboard, you will see previously executed commands including the execution of AWS-RefreshAssociation, which was performed when you set up inventory.
  2. (Optional) choose a Command ID from the list and examine the record of the command execution.
  3. Choose Run Command in the top right of the window.
  4. In the Run a command window, under Command document:
    • Choose the search icon and select Platform types, and then choose Linux to display all the available commands that can be applied to Linux instances.
    • Choose AWS-RunPatchBaseline in the list.
  5. In the Command parameters section, leave the Operation value as the default Scan.
  6. In the Targets section:
    • Under Specify targets by, choose Specifying a tag to reveal the Tags sub-section.
    • Under Enter a tag key, enter Workload, and under Enter a tag value, enter Test and click Add.

The remaining Run Command features enable you to:

  • Specify Rate control, limiting Concurrency to a specific number of targets or a calculated percentage of systems, or to specify an Error threshold by count or percentage of systems after which the command execution will end.
  • Specify Output options to record the entire output to a preconfigured S3 bucket and optional S3 key prefix.

NoteOnly the last 2500 characters of a command document’s output are displayed in the console.

  • Specify SNS notifications to a specified SNS Topic on all events or on a specific event type for either the entire command or on a per-instance basis. This requires Amazon SNS to be preconfigured.
  • View the command as it would appear if executed within the AWS Command Line Interface.
  1. Choose Run to execute the command and return to its details page.
  2. Scroll down to Targets and outputs to view the status of the individual targets that were selected through your tag key and value pair. Refresh your page to update the status.
  3. Choose an Instance ID from the targets list to view the Output from command execution on that instance.
  4. Choose Step 1 - Output to view the first 2500 characters of the command output from Step 1 of the command, and choose Step 1 - Output again to conceal it.
  5. Choose Step 2 - Output to view the first 2500 characters of the command output from Step 2 of the command. The execution step for PatchWindows was skipped as it did not apply to your Amazon Linux instance.
  6. Choose Step 1 - Output again to conceal it.

5.5 Review Initial Patch Compliance

  1. Under Instances & Nodes in the the AWS Systems Manager navigation bar, choose Compliance.
  2. On the Compliance page in the Compliance resources summary, you will now see that there are 4 systems that have critical severity compliance issues. In the Resources list, you will see the individual compliance status and details.

5.6 Patch Your Instances with AWS-RunPatchBaseline via Run Command

  1. Under Instances and Nodes in the AWS Systems Manager navigation bar, choose Run Command.
  2. Choose Run Command in the top right of the window.
  3. In the Run a command window, under Command document:
    1. Choose the search icon, select Platform types, and then choose Linux to display all the available commands that can be applied to Linux instances.
    2. Choose AWS-RunPatchBaseline in the list.
  4. In the Targets section:
    1. Under Specify targets by, choose Specifying a tag to reveal the Tags sub-section.
    2. Under Enter a tag key, enter Workload and under Enter a tag value enter Test.
  5. In the Command parameters section, change the Operation value to Install.
  6. In the Targets section, choose Specify a tag using Workload and Test.

Note You could have choosen Manually selecting instances and used the check box at the top of the list to select all instances displayed, or selected them individually.

Note there are multiple pages of instances. If manually selecting instances, individual selections must be made on each page.

  1. In the Rate control section:
    1. For Concurrency, ensure that targets is selected and specify the value as 1.

    TipLimiting concurrency will stagger the application of patches and the reboot cycle, however, to ensure that your instances are not rebooting at the same time, create separate tags to define target groups and schedule the application of patches at separate times.

    1. For Error threshold, ensure that error is selected and specify the value as 1.
  2. Choose Run to execute the command and to go to its details page.
  3. Refresh the page to view updated status and proceed when the execution is successful.

WarningRemember, if any updates are installed by Patch Manager, the patched instance is rebooted.

5.7 Review Patch Compliance After Patching

  1. Under Instances & Nodes in the the AWS Systems Manager navigation bar, choose Compliance.
  2. The Compliance resources summary will now show that there are 4 systems that have satisfied critical severity patch compliance.

In the optional Scheduling Automated Operations Activities section of this lab you can set up Systems Manager Maintenance Windows and schedule the automated application of patches.

The Impact of Operations as Code

In a traditional environment, you would have had to set up the systems and software to perform these activities. You would require a server to execute your scripts. You would need to manage authentication credentials across all of your systems.

Operations as code reduces the resources, time, risk, and complexity of performing operations tasks and ensures consistent execution. You can take operations as code and automate operations activities by using scheduling and event triggers. Through integration at the infrastructure level you avoid “swivel chair” processes that require multiple interfaces and systems to complete a single operations activity.