Systems Manager Documents. Another central idea of Systems Manager relates to Documents. Many of the Systems Manager features like the run command define the actions steps to be performed via Documents. Documents are independent resources written in JSON or YAML and allow you to include action steps and parameter values to be used. Systems Manager supports over half a dozen document types. In our case, we discussed the most common type of document used by Systems Manager, and it is called a Command document.

Command documents are used with the run command to define the actions to execute on instances and what specific values to use. Command documents are also used by the State Manager feature of Systems Manager to apply configurations to your instances. Finally, Maintenance Windows use Command documents to apply configurations based on a predefined schedule. With a Command document, you can run a shell script, configure CloudWatch, configure Docker, or perform any administrative tasks on a managed instance.

There are more than 100 preconfigured Systems Manager documents that you can use by specifying parameters at runtime. You can also modify a document or use it as is. Commonly used documents with the run command are the AWS run Shell Scripts for Linux and AWS run PowerShell Script document for Windows Systems. Documents live in the Systems Manager Documents Store and are a shared resource. We will be mostly dealing with Command documents, which are used by the run command and State Manager features of Systems Manager.

Now that we are clear with the setup and documents, let's review some of the fundamental operations we can perform with Systems Manager.