diff options
| author | Janet Kuo <chiachenk@google.com> | 2018-08-23 10:48:25 -0700 |
|---|---|---|
| committer | Janet Kuo <chiachenk@google.com> | 2018-08-23 10:48:25 -0700 |
| commit | dd4ae8273f289e490bc0b95caad574f2d9ed90ed (patch) | |
| tree | 6c351ac9c2b61601376215ae4f7f42f38628d0c8 | |
| parent | ca492c06556dbec4df1e5ac167f17124e771a746 (diff) | |
Further clarify defaulting rules & remove example
| -rw-r--r-- | contributors/devel/api_changes.md | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/contributors/devel/api_changes.md b/contributors/devel/api_changes.md index 3daf8eac..b4bc8c67 100644 --- a/contributors/devel/api_changes.md +++ b/contributors/devel/api_changes.md @@ -297,10 +297,14 @@ was added. apiserver doesn't render resources in etcd undecodable after rollback. * Any field with a default value in one API version must have *non-nil default - values* in all API versions. If a new field with a default value is introduced - in a new API version, it is required to add a default value semantically - equivalent to an unset value in old API versions, to preserve the semantic - meaning of the value being unset in previous API versions. + values* in all API versions. If a default value is added to a field in one API + version, and the field didn't have a default value in previous API versions, + it is required to add a default value semantically equivalent to an unset + value to the field in previous API versions, to preserve the semantic + meaning of the value being unset. This includes: + * a new optional field with a default value is introduced in a new API version + * an old optional field without a default value (i.e. can be nil) has a + default value in a new API version ## Incompatible API changes @@ -377,10 +381,7 @@ need to add cases to `pkg/apis/<group>/<version>/defaults.go`. values in all API versions, instead of leaving new fields unset (e.g. `nil`) in old API versions. This is required because defaulting happens whenever a serialized version is read (see [#66135]). When possible, pick meaningful values -as sentinels for unset values. For example, -`DeploymentSpec.ProgressDeadlineSeconds *int32` can have "max int32" (i.e. -2^31-1) as its default value, which is semantically equivalent to unset. When -using max int, be careful not to exceed 2^53-1 (see [#17095]). +as sentinels for unset values. In the past the core v1 API was special. Its `defaults.go` used to live at `pkg/api/v1/defaults.go`. @@ -399,7 +400,6 @@ pick a default. Don't forget to run the tests! [#66135]: https://github.com/kubernetes/kubernetes/issues/66135 -[#17095]: https://github.com/kubernetes/kubernetes/issues/17095 ### Edit conversion.go |