Tiering Storage Configuration Improvements

[bensoer]

Background
Currently storage uses 3 tiers, Standard, Infrequent Access and Glacier. This is all set using the switchToWhateverTierAfterDays parameters.

Tiering is also assumed to be from most expensive to cheapest: Standard > Infrequent Access > Glacier . This functionality is assumed when viewing the settings

Problem
When switchToWhateverTierAfterDays is set to 0. The behavior is that the entry is not added to the lifecycle. This works if you want to skip InfrequentAccess and go straight to Glacier after X number of days. But if both settings are 0. Then everything will stay in Standard Tier. This is confusing and does not reflect intuitively to the expected functionality

Code Sample of the current functionality

if(switchToInfrequentAccessTierAfterDays !== undefined 
    && switchToInfrequentAccessTierAfterDays > 0){

    transitions.push(
        {
            storageClass: s3.StorageClass.INFREQUENT_ACCESS,
            transitionAfter: Duration.days(switchToInfrequentAccessTierAfterDays)
        }
    )
}else if(switchToInfrequentAccessTierAfterDays === undefined){
    transitions.push(
        {
            storageClass: s3.StorageClass.INFREQUENT_ACCESS,
            transitionAfter: defaultInfrequentAccessTransitionDuration
        }
    )
}

Resolution
Having 0 days should mean that it is then immediatly sent to the next storage tier. If all parameters have 0 days, then everything should be going straight to Glacier storage.

IF switchToInfrequentAccessTierAfterDays is 0. Then any upload should immediatly go into InfrequentAccess
IF switchToGlacierAccessTierAfterDays is 0. Then any upload should immediatly go into Glacier

IF switchToInfrequentAccessTierAfterDays is 0 AND switchToGlacierAccessTierAfterDays is 0. Then any upload should immediatly go info Glacier