This client provides access to the full Kubernetes & OpenShift 3 REST APIs via a fluent DSL.

The easiest way to create a client is:

KubernetesClient client = new DefaultKubernetesClient();

DefaultKubernetesClient implements both the KubernetesClient & OpenShiftClient interface so if you need the OpenShift extensions, such as Builds, etc then simply do:

OpenShiftClient osClient = new DefaultOpenShiftClient();

This will use settings from different sources in the following order of priority:

• System properties
• Environment variables
• Kube config file
• Service account token & mounted CA certificate

System properties are preferred over environment variables. The following system properties & environment variables can be used for configuration:

• kubernetes.master / KUBERNETES_MASTER
• kubernetes.api.version / KUBERNETES_API_VERSION
• kubernetes.oapi.version / KUBERNETES_OAPI_VERSION
• kubernetes.tls.protocols / KUBERNETES_TLS_PROTOCOLS
• kubernetes.trust.certificates / KUBERNETES_TRUST_CERTIFICATES
• kubernetes.certs.ca.file / KUBERNETES_CERTS_CA_FILE
• kubernetes.certs.ca.data / KUBERNETES_CERTS_CA_DATA
• kubernetes.certs.client.file / KUBERNETES_CERTS_CLIENT_FILE
• kubernetes.certs.client.data / KUBERNETES_CERTS_CLIENT_DATA
• kubernetes.certs.client.key.file / KUBERNETES_CERTS_CLIENT_KEY_FILE
• kubernetes.certs.client.key.data / KUBERNETES_CERTS_CLIENT_KEY_DATA
• kubernetes.certs.client.key.algo / KUBERNETES_CERTS_CLIENT_KEY_ALGO
• kubernetes.certs.client.key.passphrase / KUBERNETES_CERTS_CLIENT_KEY_PASSPHRASE
• kubernetes.auth.basic.username / KUBERNETES_AUTH_BASIC_USERNAME
• kubernetes.auth.basic.password / KUBERNETES_AUTH_BASIC_PASSWORD
• kubernetes.auth.tryKubeConfig / KUBERNETES_AUTH_TRYKUBECONFIG
• kubernetes.auth.tryServiceAccount / KUBERNETES_AUTH_TRYSERVICEACCOUNT
• kubernetes.auth.token / KUBERNETES_AUTH_TOKEN
• kubernetes.watch.reconnectInterval / KUBERNETES_WATCH_RECONNECTINTERVAL
• kubernetes.watch.reconnectLimit / KUBERNETES_WATCH_RECONNECTLIMIT

Alternatively you can use the ConfigBuilder to create a config object for the Kubernetes client:

Config config = new DefaultKubernetesClient.ConfigBuilder().masterUrl("https://mymaster.com").build;
KubernetesClient client = new DefaultKubernetesClient(config);

Using the DSL is the same for all resources.

List resources:

NamespaceList myNs = client.namespaces().list();

ServiceList myServices = client.services().list();

ServiceList myNsServices = client.services().inNamespace("default").list();

Get a resource:

Namespace myns = client.namespaces().withName("myns").get();

Service myservice = client.services().inNamespace("default").withName("myservice").get();

Delete:

Namespace myns = client.namespaces().withName("myns").delete();

Service myservice = client.services().inNamespace("default").withName("myservice").delete();

Editing resources uses the inline builders from the Kubernetes Model:

Namespace myns = client.namespaces().withName("myns").edit()
                   .editMetadata()
                     .addToLabels("a", "label")
                   .endMetadata()
                   .done();

Service myservice = client.services().inNamespace("default").withName("myservice").edit()
                     .editMetadata()
                       .addToLabels("another", "label")
                     .endMetadata()
                     .done();

In the same spirit you can inline builders to create:

Namespace myns = client.namespaces().createNew()
                   .editMetadata()
                     .withName("myns")
                     .addToLabels("a", "label")
                   .endMetadata()
                   .done();

Service myservice = client.services().inNamespace("default").createNew()
                     .editMetadata()
                       .withName("myservice")
                       .addToLabels("another", "label")
                     .endMetadata()
                     .done();

The client supports plug-able adapters. An example adapter is the OpenShift Adapter which allows adapting an existing KubernetesClient instance to an OpenShiftClient one.

For example:

KuberntesClient client = new DefaultKubernetesClient();

OpenShiftClient oClient = client.adapt(OpenShiftClient.class);

The client also support the isAdaptable() method which checks if the adaptation is possible and returns true if it does.

KuberntesClient client = new DefaultKubernetesClient();
if (client.isAdaptable(OpenShiftClient.class)) {
    OpenShiftClient oClient = client.adapt(OpenShiftClient.class);
} else {
    throw new Exception("Adapting to OpenShiftClient not support. Check if adapter is present, and that env provides /oapi root path.");
}

Note that when using adapt() both the adaptee and the target will share the same resources (underlying http client, thread pools etc). This means that close() is not required to be used on every single instance created via adapt. Calling close() on any of the adapt() managed instances or the original instance, will properly clean up all the resources and thus none of the instances will be usable any longer.