BuildCacheRetentionDays
Number of days to retain cache images in the {rack}-build-cache ECR repository before the lifecycle policy expires them. This value applies only when BuildCacheCleanup is Yes. With cleanup off there is no expiry policy and this value has no effect.
| Default value | 30 |
| Allowed values | 1 to 365 |
Use Cases
- Capping storage cost in the build cache repository by expiring stale layers on a fixed schedule
- Keeping recent cache layers long enough to stay warm across frequent Builds while still trimming old ones
- Aligning cache retention with an organization's image retention or compliance window
Additional Information
When BuildCache is Yes, the Rack provisions a dedicated ECR repository named {rack}-build-cache that stores intermediate cache images shared across Builds. By default these images are kept indefinitely. Setting BuildCacheCleanup to Yes attaches an ECR lifecycle policy to that repository, and BuildCacheRetentionDays controls the age threshold the policy uses.
The lifecycle policy expires any cache image more than BuildCacheRetentionDays days past its push time, measured from when the image was last pushed. Lower the value to reclaim ECR storage sooner, or raise it to keep cache layers warm for longer between Builds.
$ convox rack params set BuildCacheRetentionDays=14
Setting this parameter while cleanup is off changes the stored value but has no operational effect until cleanup is enabled. To turn on expiry and set the window in one update, batch both parameters into a single command.
$ convox rack params set BuildCacheCleanup=Yes BuildCacheRetentionDays=14
Prerequisites
The build cache repository only exists when BuildCache is Yes. With the build cache disabled there is no repository, no lifecycle policy, and this parameter has no effect. Gen1 Apps do not use the build cache, so this parameter does not apply to them.
Related Rack parameters
- BuildCache creates the dedicated build cache repository
- BuildCacheCleanup attaches the lifecycle policy that expires cache images (this parameter has no effect unless that one is
Yes)
See Also
