CLIrrus and Cirrus Deployments

CLIrrus is designed around interacting with a different cirrus deployments. Many of the commands are focused on interacting with a specific cirrus ‘deployment’, like invoking a specific workflow to run in a specific deployment. A ‘cirrus deployment’ can be considered to be the collection of related AWS resources for a single cirrus deployment. For CLIrrus, a ‘deployment’ is represented as a collection of essential environment variables that are necessary to interact with the correct AWS resources for a deployment, like relevant ARNs or SQS queue URLs. These environment variables for connecting to the correct resources are stored in the AWS Parameter Store

Deployments and Parameter Store

As previously mentined, using CLIrrus requires knowing deployment specific environment variables to make AWS API calls to the correct resources. These environment variables are stored in the AWS Parameter Store. For example, the process lambda requires the “CIRRUS_PAYLOAD_BUCKET” environment variable to know what bucket to dump payloads into for storage. When running commands on a specific deployment CLIrrus will automatically retrieve these environment variables based on the deployment name you pass.

Parameter Store

The parameter store has a hierarchical storage system centered around the use of / in parameter names. More information on parameter hierachies can be found on the AWS parameter store documentation. This hierarchial organization is used to ensure deployments can be found under common prefixes, and enables for easy use if you wish to directly search the parameter store yourself.

CLIrrus utilizes the parameter store to store these critical environment variables for different deployments. When you run a command on a specific named cirrus deployment CLIrrus first retrieves the environmental variables for that cirrus deployment from the parameter store and then uses them to execute commands like list-lambdas

A pointer system is used to identify the parameter store prefix for a given deployment to ensure that we can search and retrieve only the enviroment variables for a given deployment without having to parse a large amount of returned parameters. Using this pointer CLIrrus can then retrieve the related environment variables.