Go clients for talking to a kubernetes cluster.
We currently recommend using the v3.0.0 tag. See INSTALL.md for
detailed installation instructions. go get k8s.io/client-go/... works, but
will give you head and doesn't handle the dependencies well.
- The
kubernetespackage contains the clientset to access Kubernetes API. - The
discoverypackage is used to discover APIs supported by a Kubernetes API server. - The
dynamicpackage contains a dynamic client that can perform generic operations on arbitrary Kubernetes API objects. - The
transportpackage is used to set up auth and start a connection. - The
tools/cachepackage is useful for writing controllers.
client-go follows semver. We will not make
backwards-incompatible changes without incrementing the major version number. A
change is backwards-incompatible either if it i) changes the public interfaces
of client-go, or ii) makes client-go incompatible with otherwise supported
versions of Kubernetes clusters.
Changes that add features in a backwards-compatible way will result in bumping the minor version (second digit) number.
Bugfixes will result in the patch version (third digit) changing. PRs that are
cherry-picked into an older Kubernetes release branch will result in an update
to the corresponding branch in client-go, with a corresponding new tag
changing the patch version.
A consequence of this is that client-go version numbers will be unrelated to
Kubernetes version numbers.
We will create a new branch and tag for each increment in the major version number or minor version number. We will create only a new tag for each increment in the patch version number. See semver for definitions of major, minor, and patch.
The master branch will track HEAD in the main Kubernetes repo and
accumulate changes. Consider HEAD to have the version x.(y+1).0-alpha or
(x+1).0.0-alpha (depending on whether it has accumulated a breaking change or
not), where x and y are the current major and minor versions.
client-go follows semver, so until the major version of
client-go gets increased, your code will compile and will continue to work with
explicitly supported versions of Kubernetes clusters. You must use a dependency
management system and pin a specific major version of client-go to get this
benefit, as HEAD follows the upstream Kubernetes repo.
Since Kubernetes is backwards compatible with clients, older client-go
versions will work with many different Kubernetes cluster versions.
We will backport bugfixes--but not new features--into older versions of
client-go.
| Kubernetes 1.3 | Kubernetes 1.4 | Kubernetes 1.5 | Kubernetes 1.6 | Kubernetes 1.7 | |
|---|---|---|---|---|---|
| client-go 1.4 | + | ✓ | - | - | - |
| client-go 1.5 | + | + | - | - | - |
| client-go 2.0 | + | + | ✓ | - | - |
| client-go 3.0 | † | † | † | ✓ | - |
| client-go 4.0.beta.0 | † | † | † | + | ✓ |
| client-go HEAD | † | † | † | + | + |
Key:
✓Exactly the same features / API objects in both client-go and the Kubernetes version.+client-go has features or api objects that may not be present in the Kubernetes cluster, but everything they have in common will work. Please note that alpha APIs may vanish or change significantly in a single release.†client-go has new features or api objects, and some APIs running in the cluster may have been deprecated and removed from client-go. But everything they share in common (i.e., most APIs) will work.-The Kubernetes cluster has features the client-go library can't use (additional API objects, etc).
See the CHANGELOG for a detailed description of changes between client-go versions.
| Branch | Canonical source code location | Maintenance status |
|---|---|---|
| client-go 1.4 | Kubernetes main repo, 1.4 branch | = - |
| client-go 1.5 | Kubernetes main repo, 1.5 branch | = - |
| client-go 2.0 | Kubernetes main repo, 1.5 branch | ✓ |
| client-go 3.0 | Kubernetes main repo, 1.6 branch | ✓ |
| client-go HEAD | Kubernetes main repo, master branch | ✓ |
Key:
✓Changes in main Kubernetes repo are actively published to client-go by a bot=Maintenance is manual, only severe security bugs will be patched.-Deprecated; please upgrade.
We will maintain branches for at least six months after their first stable tag is cut. (E.g., the clock for the release-2.0 branch started ticking when we tagged v2.0.0, not when we made the first alpha.) This policy applies to every version greater than or equal to 2.0.
For the initial release of client-go, we thought it would be easiest to keep separate directories for each minor version. That soon proved to be a mistake. We are keeping the top-level folders in the 1.4 and 1.5 branches so that existing users won't be broken.
You can use go get k8s.io/client-go/... to get client-go, but you will get
the unstable master branch and client-go's vendored dependencies will not be
added to your $GOPATH. So we think most users will want to use a dependency
management system. See INSTALL.md for detailed instructions.
If your application runs in a Pod in the cluster, please refer to the in-cluster example, otherwise please refer to the out-of-cluster example.
If your application depends on a package that client-go depends on, and you let the Go compiler find the dependency in GOPATH, you will end up with duplicated dependencies: one copy from the GOPATH, and one from the vendor folder of client-go. This will cause unexpected runtime error like flag redefinition, since the go compiler ends up importing both packages separately, even if they are exactly the same thing. If this happens, you can either
- run
godep restore(godep) in the client-go/ folder, then remove the vendor folder of client-go. Then the packages in your GOPATH will be the only copy - or run
godep savein your application folder to flatten all dependencies.
Please send pull requests against the client packages in the Kubernetes main repository. Changes in the staging area will be published to this repository every day.