Impossible de se connecter à l'API kubernetes depuis l'intérieur du cluster

Question

J'essaie d'utiliser le fabric8io/kubernetes-client dans un exemple simple sur mon minikube local où je reçois l'IP d'un pod

import io.fabric8.kubernetes.client.Config;
import io.fabric8.kubernetes.client.ConfigBuilder;
import io.fabric8.kubernetes.client.DefaultKubernetesClient;
import io.fabric8.kubernetes.client.KubernetesClient;

public class PodLogExample {

  public static void main(String[] args) throws InterruptedException {

    String podName = "some-pod-name-jnfen3";
    String namespace = "default";
    String master = "https://localhost:32780/";

    Config config = new ConfigBuilder().withMasterUrl(master).build();
    KubernetesClient client = new DefaultKubernetesClient(config);
    String podIP = client.pods().inNamespace(namespace).withName(podName).get().getStatus().getPodIP();
    System.out.println("Pod IP is: " + podIP);
    Thread.sleep(5 * 1000);
    client.close();
  }
}

some-pod-name-jnfen3 est le nom d'un pod qui a terminé son exécution et qui est visible si j'exécute kubectl get pods .

https://localhost:32780/ est un hôte API kubernetes que j'obtiens à partir de kubectl config view -o jsonpath="{.clusters[?(@.name==\"minikube\")].cluster.server}" .

• minikube n'a qu'un seul noeud.
• la version de fabric8io/kubernetes-client est 4.9.1
• Java 11

Je déploie ce code en tant que Job sur le même cluster que l'application some-pod-name-jnfen3 . Voici l'exception :

Exception in thread "main" io.fabric8.kubernetes.client.KubernetesClientException: Operation: [get]  for kind: [Pod]  with name: [some-pod-name-jnfen3]  in namespace: [default]  failed.
    at io.fabric8.kubernetes.client.KubernetesClientException.launderThrowable(KubernetesClientException.java:64)
    at io.fabric8.kubernetes.client.KubernetesClientException.launderThrowable(KubernetesClientException.java:72)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:225)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.get(BaseOperation.java:168)
    at PodLogExample.main(PodLogExample.java:16)
Caused by: java.net.ConnectException: Failed to connect to localhost/127.0.0.1:32780
    at okhttp3.internal.connection.RealConnection.connectSocket(RealConnection.java:249)
    at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:167)
    at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:258)
    at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:135)
    at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:114)
    at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:127)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at io.fabric8.kubernetes.client.utils.BackwardsCompatibilityInterceptor.intercept(BackwardsCompatibilityInterceptor.java:134)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at io.fabric8.kubernetes.client.utils.ImpersonatorInterceptor.intercept(ImpersonatorInterceptor.java:68)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at io.fabric8.kubernetes.client.utils.HttpClientUtils.lambda$createHttpClient$3(HttpClientUtils.java:112)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:257)
    at okhttp3.RealCall.execute(RealCall.java:93)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:469)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:430)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:395)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:376)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.handleGet(BaseOperation.java:845)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:214)
    ... 2 more
Caused by: java.net.ConnectException: Connection refused (Connection refused)
    at java.base/java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399)
    at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242)
    at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224)
    at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403)
    at java.base/java.net.Socket.connect(Socket.java:609)
    at okhttp3.internal.platform.Platform.connectSocket(Platform.java:129)
    at okhttp3.internal.connection.RealConnection.connectSocket(RealConnection.java:247)
    ... 34 more

Pour une raison quelconque, il ne peut pas se connecter à l'hôte API de Kubernetes.

Comment puis-je le réparer ?

UPDATE

Si je ne passe pas le config au client, il obtient l'IP correcte du maître et échoue ensuite avec l'exception suivante

Exception in thread "main" io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: GET at: https://10.96.0.1/api/v1/namespaces/default/pods/some-pod-name-jnfen3. Message: Forbidden!Configured service account doesn't have access. Service account may have been revoked. pods "some-pod-name-jnfen3" is forbidden: User "system:serviceaccount:default:default" cannot get resource "pods" in API group "" in the namespace "default".
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.requestFailure(OperationSupport.java:568)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.assertResponseCode(OperationSupport.java:505)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:471)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:430)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:395)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:376)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.handleGet(BaseOperation.java:845)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:214)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.get(BaseOperation.java:168)
    at PodLogExample.main(PodLogExample.java:17)

Answer 1

kubectl config view -o jsonpath="{.clusters[?(@.name==\"minikube\")].cluster.server}" renvoie l'IP relatif. C'est différent pour le Pod.

Ne passe pas config permettra à la bibliothèque de trouver la bonne adresse IP.

Un nouveau compte de service doit également être créé et défini dans le fichier job.yaml.

En default Le compte de service n'a pas les permissions pour récupérer les entités k8s.

Related Numéro de GitHub

Answer 2

C'est localhost du point de vue de votre ordinateur portable, mais pas de l'intérieur du cluster. Utilisez plutôt les aides InClusterConfig.