Amazon SSM Agent

The Amazon EC2 Simple Systems Manager (SSM) Agent is software developed for the Simple Systems Manager Service. The SSM Agent is the primary component of a feature called Run Command.

Overview

The SSM Agent runs on EC2 instances and enables you to quickly and easily execute remote commands or scripts against one or more instances. The agent uses SSM documents. When you execute a command, the agent on the instance processes the document and configures the instance as specified. Currently, the agent and Run Command enable you to quickly run Shell scripts on an instance using the AWS-RunShellScript SSM document. SSM Agent also enables the Session Manager capability that lets you manage your Amazon EC2 instance through an interactive one-click browser-based shell or through the AWS CLI. The first time a Session Manager session is started on an instance, the agent will create a user called "ssm-user" with sudo or administrator privilege. Session Manager sessions will be launched in context of this user.

Verify Requirements

• SSM Run Command Prerequisites
• SSM Session Manager Prerequisites and supported Operating Systems
• Linux systems require kernel version 3.2 or above

Setup

• Configuring IAM Roles and Users for SSM Run Command
• Configuring the SSM Agent
• Configuring IAM Roles for Session Manager
• Configuring Users for Session Manager

Executing Commands

SSM Run Command Walkthrough Using the AWS CLI

Starting Sessions

Session Manager Walkthrough Using the AWS Console and CLI

Troubleshooting

Troubleshooting SSM Run Command Troubleshooting SSM Session Manager

Feedback

Thank you for helping us to improve Systems Manager, Run Command and Session Manager. Please send your questions or comments to Systems Manager Forums

Building inside docker container (Recommended)

• Install docker: Install CentOS

• Build image

docker build -t ssm-agent-build-image .

• Build the agent

docker run -it --rm --name ssm-agent-build-container -v `pwd`:/amazon-ssm-agent ssm-agent-build-image make build-release

Building on Linux

• Install go Getting started

• Install rpm-build and rpmdevtools

• Cross Compile SSM Agent

• Run make build to build the SSM Agent for Linux, Debian, Windows environment.

• Run make build-release to build the agent and also packages it into a RPM, DEB and ZIP package.

The following folders are generated when the build completes:

bin/debian_386
bin/debian_amd64
bin/linux_386
bin/linux_amd64
bin/linux_arm
bin/linux_arm64
bin/windows_386
bin/windows_amd64

• To enable the Agent for Session Manager scenario on Windows instances
  • Clone the repo from https://github.com/masatma/winpty.git
  • Follow instructions on https://github.com/rprichard/winpty to build winpty 64-bit binaries
  • Copy the winpty.dll and winpty-agent.exe to the bin/SessionManagerShell folder For the Windows Operating System, Session Manager is only supported on Windows Server 2008 R2 through Windows Server 2019 64-bit versions.

Please follow the user guide to copy and install the SSM Agent

Code Layout

• Source code
  • Core functionality such as worker management is under core/
  • Agent worker code is under agent/
  • Other functionality such as IPC is under common/
• Vendor package source code is under vendor/src
• rpm and dpkg artifacts are under packaging
• build scripts are under Tools/src

Linting

To lint the entire module call the lint-all target. This executes golangci-lint on all packages in the module. You can configure golangci-lint with different linters using the .golangci.yml file.

For golangci-lint installation instructions see https://golangci-lint.run/usage/install/ For more information on the golangci-lint configuration file see https://golangci-lint.run/usage/configuration/ For more information on the linters used see https://golangci-lint.run/usage/linters/

GOPATH

To use vendor dependencies, the suggested GOPATH format is :<packagesource>/vendor:<packagesource>

Make Targets

The following targets are available. Each may be run with make <target>.

Make Target	Description
build	(Default) build builds the agent for Linux, Debian, Darwin and Windows amd64 and 386 environment
build-release	build-release checks code style and coverage, builds the agent and also packages it into a RPM, DEB and ZIP package
release	release checks code style and coverage, runs tests, packages all dependencies to the bin folder.
package	package packages build result into a RPM, DEB and ZIP package
pre-build	pre-build goes through Tools/src folder to make sure all the script files are executable
checkstyle	checkstyle runs the checkstyle script
analyze-install	analyze-install install static analysis dependencies for local use
analyze	analyze runs static analysis script to find possible vulnerabilities
quick-integtest	quick-integtest runs all tests tagged with integration using go test
quick-test	quick-test runs all the tests including integration and unit tests using go test
coverage	coverage runs all tests and calculate code coverage
build-linux	build-linux builds the agent for execution in the Linux amd64 environment
build-windows	build-windows builds the agent for execution in the Windows amd64 environment
build-darwin	build-darwin builds the agent for execution in the Darwin amd64 environment
build-linux-386	build-linux-386 builds the agent for execution in the Linux 386 environment
build-windows-386	build-windows-386 builds the agent for execution in the Windows 386 environment
build-darwin-386	build-darwin-386 builds the agent for execution in the Darwin 386 environment
build-arm	build-arm builds the agent for execution in the arm environment
build-arm64	build-arm64 builds the agent for execution in the arm64 environment
lint-all	lint-all runs golangci-lint on all packages. golangci-lint is configured by .golangci.yml
package-rpm	package-rpm builds the agent and packages it into a RPM package for Linux amd64 based distributions
package-deb	package-deb builds the agent and packages it into a DEB package Debian amd64 based distributions
package-win	package-win builds the agent and packages it into a ZIP package Windows amd64 based distributions
package-rpm-386	package-rpm-386 builds the agent and packages it into a RPM package for Linux 386 based distributions
package-deb-386	package-deb-386 builds the agent and packages it into a DEB package Debian 386 based distributions
package-win-386	package-win-386 builds the agent and packages it into a ZIP package Windows 386 based distributions
package-rpm-arm64	package-rpm-arm64 builds the agent and packages it into a RPM package Linux arm64 based distributions
package-deb-arm	package-deb-arm builds the agent and packages it into a DEB package Debian arm based distributions
package-deb-arm64	package-deb-arm64 builds the agent and packages it into a DEB package Debian arm64 based distributions
package-linux	package-linux create update packages for Linux and Debian based distributions
package-windows	package-windows create update packages for Windows based distributions
package-darwin	package-darwin create update packages for Darwin based distributions
get-tools	get-tools gets gocode and oracle using go get
clean	clean removes build artifacts

Contributing

Contributions and feedback are welcome! Proposals and Pull Requests will be considered and responded to. Please see the CONTRIBUTING.md file for more information.

Amazon Web Services does not currently provide support for modified copies of this software.

Runtime Configuration

To set up your own custom configuration for the agent:

• Navigate to /etc/amazon/ssm/ (or C:\Program Files\Amazon\SSM for windows)
• Copy the contents of amazon-ssm-agent.json.template to a new file amazon-ssm-agent.json
• Restart agent

Config Property Definitions:

• Profile - represents configurations for aws credential profile used to get managed instance role and credentials
  • ShareCreds (boolean)
    • Default: true
  • ShareProfile (string)
  • ForceUpdateCreds (boolean) - overwrite shared credentials file if existing one cannot be parsed
    • Default: false
  • KeyAutoRotateDays (int) - defines the maximum age in days for on-prem private key, default value might change to 30 in the close future
    • Default: 0 (never rotate)
• Mds - represents configuration for Message delivery service (MDS) where agent listens for incoming messages
  • CommandWorkersLimit (int)
    • Default: 5
  • StopTimeoutMillis (int64)
    • Default: 20000
  • Endpoint (string)
  • CommandRetryLimit (int)
    • Default: 15
• Ssm - represents configuration for Simple Systems Manager (SSM)
  • Endpoint (string)
  • HealthFrequencyMinutes (int)
    • Default: 5
  • CustomInventoryDefaultLocation (string)
  • AssociationLogsRetentionDurationHours (int)
    • Default: 24
  • RunCommandLogsRetentionDurationHours (int)
    • Default: 336
  • SessionLogsRetentionDurationHours (int)
    • Default: 336
  • SessionLogsDestination (string) - Configure where you want Session Manager to write session data.
    • Default: "none" - Don't write session data anywhere when CloudWatch and S3 logging are disabled.
    • OptionalValue: "disk" - Write session data to disk.
  • PluginLocalOutputCleanup (string) - Configure when after execution it is safe to delete local plugin output logs in orchestration folder
    • Default: "" - Don't delete logs immediately after execution. Fall back to AssociationLogsRetentionDurationHours, RunCommandLogsRetentionDurationHours, and SessionLogsRetentionDurationHours
    • OptionalValue: "after-execution" - Delete plugin output file locally after plugin execution
    • OptionalValue: "after-upload" - Delete plugin output locally after successful s3 or cloudWatch upload
  • OrchestrationDirectoryCleanup (string) - Configure only when it is safe to delete orchestration folder after document execution. This config overrides PluginLocalOutputCleanup when set.
    • Default: "" - Don't delete orchestration folder after execution
    • OptionalValue: "clean-success" - Deletes the orchestration folder only for successful document executions.
    • OptionalValue: "clean-success-failed" - Deletes the orchestration folder for successful and failed document executions.
• Mgs - represents configuration for Message Gateway service
  • Region (string)
  • Endpoint (string)
  • StopTimeoutMillis (int64)
    • Default: 20000
  • SessionWorkersLimit (int)
    • Default: 1000
  • DeniedPortForwardingRemoteIPs ([]string)
    • Default: [ "169.254.169.254", "fd00:ec2::254", "169.254.169.253", "fd00:ec2::253", "169.254.169.123", "fd00:ec2::123", "169.254.169.250", "169.254.169.251", "fd00:ec2::240"]
• Agent - represents metadata for amazon-ssm-agent
  • Region (string)
  • OrchestrationRootDir (string)
    • Default: "orchestration"
  • SelfUpdate (boolean)
    • Default: false
  • TelemetryMetricsToCloudWatch (boolean)
    • Default: false
  • TelemetryMetricsToSSM (boolean)
    • Default: true
  • AuditExpirationDay (int)
    • Default: 7
  • LongRunningWorkerMonitorIntervalSeconds (int)
    • Default: 60
  • GoMaxProcForAgentWorker (int)
    • Default: 0
• Os - represents os related information, will be logged in reply messages
  • Lang (string)
    • Default: "en-US"
  • Name (string)
  • Version (string)
    • Default: 1
• S3 - represents configurations related to S3 bucket and key for SSM. Endpoint and region are typically determined automatically, and should only be set if a custom endpoint is required. LogBucket and LogKey are currently unused.
  • Endpoint (string)
    • Default: ""
  • Region (string) - Ignored
  • LogBucket (string) - Ignored
  • LogKey (string) - Ignored
• Kms - represents configuration for Key Management Service if encryption is enabled for this session (i.e. kmsKeyId is set or using "Port" plugin)
  • Endpoint (string)
  • RequireKMSChallengeResponse (boolean) - if true, enforces that Session Manager clients support enhanced challenge-response authentication
    • Default: false

Release

After the SSM Agent source code has been released to github, it can take up to 2 weeks for the install packages to propagate to all AWS regions.

The following commands can be used to pull the VERSION file and check the latest agent available in a region.

• Regional Bucket (Non-CN) - curl https://s3.{region}.amazonaws.com/amazon-ssm-{region}/latest/VERSION
  • Replace {region} with region code like us-east-1.
• Regional Bucket (CN) - curl https://s3.{region}.amazonaws.com.cn/amazon-ssm-{region}/latest/VERSION
  • Replace {region} with region code cn-north-1, cn-northwest-1.
• Global Bucket - curl https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/VERSION

License

The Amazon SSM Agent is licensed under the Apache 2.0 License.