2. Versioning and Compatibility

Client versioning

The Java client uses Semantic Versioning. We increment the major version number whenever we regenerate the client for a new Kubernetes release version (see table below). Whenever we do this there are new APIs added and possibly breaking changes in the generated Kubernetes API Stubs. Whenever you upgrade a major version, be prepared for potential breaking changes.

Compatibility

client version	1.15	1.16	1.17	1.18	1.19	1.20	1.21	1.22	1.23	1.24	1.25	1.26	1.27	1.28	1.29
7.0.x	✓	-	-	x	x	x	x	x	x	x	x	x	x	x	-
8.0.x	+	✓	-	-	x	x	x	x	x	x	x	x	x	x	-
9.0.x	+	+	✓	-	-	x	x	x	x	x	x	x	x	x	-
10.0.x	+	+	+	✓	-	-	x	x	x	x	x	x	x	x	-
11.0.x	+	+	+	+	✓	-	-	x	x	x	x	x	x	x	-
12.0.x	+	+	+	+	+	✓	-	-	x	x	x	x	x	x	-
13.0.x	+	+	+	+	+	✓	!	-	-	x	x	x	x	x	-
14.0.x	+	+	+	+	+	+	+	✓	-	-	x	x	x	x	-
15.0.x	+	+	+	+	+	+	+	+	✓	-	-	x	x	x	-
16.0.x	+	+	+	+	+	+	+	+	+	✓	-	-	x	x	-
17.0.x	+	+	+	+	+	+	+	+	+	+	✓	-	-	x	-
18.0.x	+	+	+	+	+	+	+	+	+	+	+	✓	-	-	-
19.0.x	+	+	+	+	+	+	+	+	+	+	+	+	✓	-	-
20.0.x (including legacy)	+	+	+	+	+	+	+	+	+	+	+	+	✓	-
21.0.x (including legacy)	+	+	+	+	+	+	+	+	+	+	+	+	+	✓
HEAD	+	+	+	+	+	+	+	+	+	+	+	+	+	+	+

Key:

• ✓ Exactly the same features / API objects in both java-client and the Kubernetes version.
• + java-client has features or api objects that may not be present in the Kubernetes cluster, but everything they have in common will work.
• - The Kubernetes cluster has features the java-client library can't use (additional API objects, etc).
• x The Kubernetes cluster has no guarantees to support the API client of this version, as it only promises n-2 version support. It is not tested, and operations using API versions that have been deprecated and removed in later server versions won't function correctly.
• ! There was an error in process and 13.0.0 was based on Kubernetes 1.20 rather than 1.21 as it should have been.

See the CHANGELOG for a detailed description of changes between java-client versions.