SSM Parameter Size Limit Hit for Runner Matcher Config

[edersonbrilhante]

Description:

Currently, when updating the SSM Parameter /github-action-runners/my-prefix/webhook/runner-matcher-config, we occasionally hit the AWS SSM size limit for standard parameters:

Error: updating SSM Parameter (/github-action-runners/my-prefix/webhook/runner-matcher-config): 
operation error SSM: PutParameter, https response error StatusCode: 400, RequestID: ..., 
api error ValidationException: Standard tier parameters support a maximum parameter value of 4096 characters. 
To create a larger parameter value, upgrade the parameter to use the advanced-parameter tier.

This is caused by the number of labels per runner type combined with the number of runner types exceeding the 4096-character limit.

Proposed Solutions / Improvements:

1. Support multiple SSM parameters via environment variable:
   Update PARAMETER_RUNNER_MATCHER_CONFIG_PATH to accept multiple parameter paths, separated by a colon. Example:

   /github-action-runners/my-prefix/webhook/runner-matcher-config-1:/github-action-runners/my-prefix/webhook/runner-matcher-config-2
   

   This would allow the matcher config to be split across multiple SSM parameters.

2. Use S3 for storing the matcher config:
   Instead of storing the full JSON in a single SSM parameter, allow the environment variable to point to an S3 path containing the matcher config JSON.

Impact:

• Avoid hitting SSM size limits for large runner configurations.
• Improve scalability as the number of labels and runner types grows.

References:

• [AWS SSM Parameter Store Advanced Parameters](https://docs.aws.amazon.com/systems-manager/latest/userguide/parameter-store-advanced-parameters.html)