Dev Services for Kubernetes
Dev Services for Kubernetes automatically starts a Kubernetes API server (plus the required etcd) in dev mode and when running tests. So you don’t have to start it manually. The application is configured automatically.
The following testcontainers are supported: kind, k3s or api only(default)
Enabling / Disabling Dev Services for Kubernetes
To use the Kubernetes Dev Service, you simply need to add the quarkus-kubernetes-client extension to your project:
quarkus extension add kubernetes-client./mvnw quarkus:add-extension -Dextensions='kubernetes-client'./gradlew addExtension --extensions='kubernetes-client'A Kubernetes API server is automatically started in dev or test modes whenever the quarkus-kubernetes-client extension is configured for a project. However, the dev service is disabled in some cases to prevent potential confusing situations:
-
if the dev service is explicitly disabled by setting
quarkus.kubernetes-client.devservices.enabledtofalse -
if the client is explicitly configured to access a given API server via
quarkus.kubernetes-client.api-server-url -
if a valid Kube config file is found, in which case that configuration will be used by the client. It is, however, possible to force the dev service to start anyway by setting
quarkus.kubernetes-client.devservices.override-kubeconfigtotrueto disregard the existing configuration -
if you include the
quarkus-test-kubernetes-clientdependency as, presumably, in that case, you have tests that rely on the Fabric8 mock server and don’t need to start a cluster
| Dev Services for Kubernetes relies on a container engine (Docker or Podman) to start the server. If your environment does not support such a container engine, you will have to start a Kubernetes cluster running in a VM, in the cloud, etc. In this case, you can configure the Kubernetes cluster access using either a Kube config file or the various properties available as specified in the Kubernetes client configuration guide. |
Shared cluster
Applications often need to share access to the same cluster. For that purpose, Dev Services for Kubernetes implements a service discovery mechanism for multiple Quarkus applications running in dev mode to share a single cluster.
Dev Services for Kubernetes starts the api server container with the quarkus-dev-service-kubernetes label which is used to identify it.
|
If you need multiple (shared) clusters, you can provide a value for the quarkus.kubernetes-client.devservices.service-name configuration property to specify the name of the cluster that will be shared among the selected applications. The dev service support will look for an already existing container with that specified name or starts a new one if none can be found.The default service name is kubernetes.
Sharing is enabled by default in dev mode, but disabled in test mode.
You can disable the sharing with quarkus.kubernetes-client.devservices.shared=false.
Configuring the cluster
Dev Services for Kubernetes provides three different flavors of Kubernetes cluster. Each flavor supports different Kubernetes API versions.
You can configure the flavor and version using the quarkus.kubernetes-client.devservices.flavor and quarkus.kubernetes-client.devservices.api-version properties:
quarkus.kubernetes-client.devservices.flavor=api-only # k3s or kind
quarkus.kubernetes-client.devservices.api-version=1.22You can also configure a custom image compatible with standard images (kind, k3s & api-server) using the quarkus.kubernetes-client.devservices.image-name property. However, it must be consistent with the flavor and api-version properties:
quarkus.kubernetes-client.devservices.flavor=api-only # k3s or kind
quarkus.kubernetes-client.devservices.api-version=1.24.1
quarkus.kubernetes-client.devservices.image-name=quay.io/giantswarm/kube-apiserver:v1.24.1api-only only starts a Kubernetes API Server (plus the required etcd). If you need a fully-featured Kubernetes cluster that can spin up Pods, you can use k3s or kind. k3s requires to start the container with privileged mode. The kind test container now also supports using podman’s rootless mode.
If api-version is not set, the latest version for the given flavor will be used. Otherwise, the version must match a version supported by the given flavor.
Once the cluster is configured, you can access it easily as you normally would, for example, by injecting a client instance in your test.
Applying manifests to the cluster
Within Quarkus it is possible to apply Kubernetes manifests to the cluster dev service on startup. This is especially useful if your application expects certain resources to be present in the cluster, such as for example a specific namespace or certain Custom Resource Definitions that the application interacts with.
You can configure the manifests to be applied using the quarkus.kubernetes-client.devservices.manifests property. This property accepts a list of files within the application’s resources directory.
As an example, to ensure the example-namespace namespace is present in the dev service, create the file /src/main/resources/kubernetes/namespace.yml:
apiVersion: v1
kind: Namespace
metadata:
name: example-namespaceAnd then add the following property to your application.properties:
quarkus.kubernetes-client.devservices.manifests=kubernetes/namespace.yamlDeploying helm charts
quarkus.kubernetes-client.devservices.manifests only supports manifests. If you want to deploy a helm chart, you can use the k3s flavor and deploy a HelmChart manifest. See https://docs.k3s.io/helm for more information on how to use helm charts with k3s.
Configuration reference
Configuration property fixed at build time - All other configuration properties are overridable at runtime
Configuration property |
Type |
Default |
|---|---|---|
If Dev Services for Kubernetes should be used. (default to true) If this is true and kubernetes client is not configured then a kubernetes cluster will be started and will be used. Environment variable: Show more |
boolean |
|
The kubernetes api server version to use. If not set, Dev Services for Kubernetes will use the latest supported version of the given flavor. Environment variable: Show more |
string |
|
The kubernetes image to use. If not set, Dev Services for Kubernetes will use default image for the specified Environment variable: Show more |
string |
|
The flavor to use (kind, k3s or api-only). If not set, Dev Services for Kubernetes will set it to: api-only. Environment variable: Show more |
|
|
By default, if a kubeconfig is found, Dev Services for Kubernetes will not start. Set this to true to override the kubeconfig config. Environment variable: Show more |
boolean |
|
A list of manifest file paths that should be applied to the Kubernetes cluster Dev Service on startup. If not set, no manifests are applied. Environment variable: Show more |
list of string |
|
Indicates if the Kubernetes cluster managed by Quarkus Dev Services is shared. When shared, Quarkus looks for running containers using label-based service discovery. If a matching container is found, it is used, and so a second one is not started. Otherwise, Dev Services for Kubernetes starts a new container. The discovery uses the Container sharing is only used in dev mode. Environment variable: Show more |
boolean |
|
The value of the This property is used when you need multiple shared Kubernetes clusters. Environment variable: Show more |
string |
|
Environment variables that are passed to the container. Environment variable: Show more |
Map<String,String> |
