Working with parameter hierarchies in Parameter Store
Managing dozens or hundreds of parameters as a flat list is time consuming and prone to errors. It can also be difficult to identify the correct parameter for a task. This means you might accidentally use the wrong parameter, or you might create multiple parameters that use the same configuration data.
You can use parameter hierarchies to help you organize and manage parameters. A hierarchy is a parameter name that includes a path that you define by using forward slashes (/).
Topics
Understanding parameter hierarchy through examples
The following example uses three hierarchy levels in the name to identify the following:
/Environment/Type of computer/Application/Data
/Dev/DBServer/MySQL/db-string13
You can create a hierarchy with a maximum of 15 levels. We suggest that you create hierarchies that reflect an existing hierarchical structure in your environment, as shown in the following examples:
-
Your Continuous integration
and Continuous delivery environment (CI/CD workflows) /Dev/DBServer/MySQL/db-string/Staging/DBServer/MySQL/db-string/Prod/DBServer/MySQL/db-string -
Your applications that use containers
/MyApp/.NET/Libraries/my-password -
Your business organization
/Finance/Accountants/UserList/Finance/Analysts/UserList/HR/Employees/EU/UserList
Parameter hierarchies standardize the way you create parameters and make it easier to manage parameters over time. A parameter hierarchy can also help you identify the correct parameter for a configuration task. This helps you to avoid creating multiple parameters with the same configuration data.
You can create a hierarchy that allows you to share parameters across different environments, as shown in the following examples that use passwords in development and staging environment.
/DevTest/MyApp/database/my-password
You could then create a unique password for your production environment, as shown in the following example:
/prod/MyApp/database/my-password
You aren't required to specify a parameter hierarchy. You can create parameters at level one. These are called root parameters. For backward compatibility, all parameters created in Parameter Store before hierarchies were released are root parameters. The systems treats both of the following parameters as root parameters.
/parameter-name
parameter-name
Querying parameters in a hierarchy
Another benefit of using hierarchies is the ability to query for all parameters within a hierarchy by using the GetParametersByPath API operation. For example, if you run the following command from the AWS Command Line Interface (AWS CLI), the system returns all parameters in the IIS level.
aws ssm get-parameters-by-path --path /Dev/Web/IIS
To view decrypted SecureString parameters in a hierarchy, you
specify the path and the --with-decryption parameter, as shown in
the following example.
aws ssm get-parameters-by-path --path /Prod/ERP/SAP --with-decryption
Managing parameters using hierarchies using the AWS CLI
This procedure shows how to work with parameters and parameter hierarchies by using the AWS CLI.
To manage parameters using hierarchies
Install and configure the AWS Command Line Interface (AWS CLI), if you haven't already.
For information, see Installing or updating the latest version of the AWS CLI.
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Run the following command to create a parameter that uses the
allowedPatternparameter and theStringparameter type. The allowed pattern in this example means the value for the parameter must be between 1 and 4 digits long.The command returns the version number of the parameter.
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Run the following command to attempt to overwrite the parameter you just created with a new value.
The system returns the following error because the new value doesn't meet the requirements of the allowed pattern you specified in the previous step.
An error occurred (ParameterPatternMismatchException) when calling the PutParameter operation: Parameter value, cannot be validated against allowedPattern: \d{1,4} -
Run the following command to create a
SecureStringparameter that uses an AWS managed key. The allowed pattern in this example means the user can specify any character, and the value must be between 8 and 20 characters. -
Run the following commands to create more parameters that use the hierarchy structure from the previous step.
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Run the following command to get the value of two parameters.
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Run the following command to query for all parameters within a single level.
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Run the following command to delete two parameters.
