fix(cmd): Out of Bounds int32 Check in AWS Lambda Autoscale

[andrew-kline]

Description

• Fix security finding for incorrect conversion between integer types (https://github.com/brexhq/substation/security/code-scanning/34 and https://github.com/brexhq/substation/security/code-scanning/35). This adds the upper bound check.

Motivation and Context

Solves potential overflow issue if the Kinesis downscale and upscale datapoints values are outside the upper bound for int32. This occurs in init - failure should occur pre-runtime if the env var(s) are set incorrectly.

How Has This Been Tested?

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[jshlbrd]

The max value can be any integer, so I think borrowing this logic from your first commit may work better:

if dps <= math.MaxInt32 && dps >= 1 {

Same for the other line, too.

[andrew-kline]

sounds good, adjusted - i was basing off of the readme-defined maxes

[jshlbrd]

I think that README might have been accurate at one time, but not anymore. It could use an update.