Controlling qbec behavior

qbec usually does the right thing when applying objects. Sometimes this behavior needs tweaking. Qbec allows you to annotate objects with specific directives to control its behavior. All annotations are in the namespace.

Updating and deleting objects

Usually qbec will update and delete objects as required. You can “lock” objects from being updated or deleted using the following annotations:

  • never
  • never

The first is useful when dealing with jobs that typically should not be updated. The second is useful for preventing storage objects like persistent volume claims from ever being deleted.

Note that qbec will look for these annotations on the object that is already present on the cluster and will ignore the annotations from source code when implementing these policies. This ensures, for example, that you do not accidentally start updating and deleting objects by removing these annotations from source code.

In addition if you lock a namespaced object from being deleted, qbec will automatically ensure that the corresponding namespace, if it exists, is also never deleted.

Controlling apply order

qbec apply evaluates all components in source code and internally assigns an “apply order” to every object. It then sorts this list and applies objects in order, one at a time. The default ordering applies cluster objects before namespaced objects, config maps and secrets before deployments etc.

For specific objects, you can control the apply order by setting the annotation to a numeric value as a string (e.g. "1000").

This feature should be used with care since it is possible to get nonsensical ordering (e.g. trying to apply a namespaced object before the namespace is created). The most common use of this feature is to provide a high number to delay processing of a specific object (typically a custom resource) until the end. Even in this case, qbec default processing may be enough since it automatically delays the apply of resources having unknown types to the end.

If you have many instances of a resource that needs a custom apply order, consider using a post-processor to set the annotation for all instances of the type instead of annotating each instance.