BuildCacheCleanup
Controls whether the Rack attaches an ECR lifecycle policy that expires old images in the build cache repository. When enabled, cache images older than BuildCacheRetentionDays are expired automatically. This parameter has effect only when BuildCache is set to Yes.
| Default value | No |
| Allowed values | Yes, No |
Use Cases
- Bounding the storage footprint (and ECR storage cost) of a long-lived build cache repository
- Pruning cache layers that are no longer referenced by recent Builds
- Keeping the cache repository small without manually deleting images
Additional Information
When BuildCache is set to Yes, the Rack provisions a dedicated ECR repository named {rack}-build-cache to hold persistent build cache images. BuildCacheCleanup governs the retention behavior of that repository.
When set to Yes, Convox attaches a CloudFormation-managed ECR lifecycle policy to the {rack}-build-cache repository. The policy expires any cache image older than BuildCacheRetentionDays (counted from the date each image was pushed).
When set to No, no expiry policy is attached and cache images are kept indefinitely. The cache repository grows over time. This is a storage-cost consideration, not data loss, because cache images are regenerable on the next Build.
$ convox rack params set BuildCacheCleanup=Yes
Pair this with BuildCacheRetentionDays to choose how long cache images are retained before they expire. The retention window defaults to 30 days and accepts values from 1 to 365.
Prerequisites
BuildCacheCleanup has effect only when BuildCache is Yes. With BuildCache=No, the {rack}-build-cache repository does not exist, so there is nothing for the cleanup policy to apply to. Enable the build cache first, then set the cleanup behavior:
$ convox rack params set BuildCache=Yes BuildCacheCleanup=Yes BuildCacheRetentionDays=30
Gen1 Apps do not use the build cache, so this parameter has no effect on gen1 Builds.
Disable
Set BuildCacheCleanup=No to stop expiring cache images. The lifecycle policy is removed from the {rack}-build-cache repository on the next Rack update, and existing cache images are retained from that point forward.
$ convox rack params set BuildCacheCleanup=No
See Also
