Description

This PR adds the following preset variables to the secondary storage selectors of TEMPLATE resources:

Using them, it is possible to define heuristics to avoid the redownload/copy of public templates, for instance:

for (i = 0; i < template.downloadDetails.length; i++) {
  details = template.downloadDetails[i];
  if (template.isPublic && ['NOT_DOWNLOADED', 'DOWNLOAD_IN_PROGRESS', 'DOWNLOADED'].indexOf(details.downloadState) !== -1) {
    details.dataStoreId;
    break;
  }
}

The selector above will direct the template to a secondary storage that the template is already present when it is marked as public and downloaded/downloading. Hence, it will not be duplicated to other secondary storages.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)
• build/CI
• test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Feature/Enhancement Scale

• Major
• Minor

Screenshots (if appropriate):

How Has This Been Tested?

In an environment with a single secondary storage, sec-nfs-1:

1. I created a secondary storage selector for templates with the heuristic rule available above.
2. I registered some public templates and waited until they finished downloading to sec-nfs-1.
3. I added another secondary storage, sec-nfs-2, and verified that the existing public templates were not copied/downloaded to sec-nfs-2 because the secondary storage selector was directing them to sec-nfs-1.