I’m trying to use the fabric8io/kubernetes-client in a simple example on my local minikube cluster where I get an IP of a 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 is a name of a pod which finished execution and visible if I execute kubectl get pods.
https://localhost:32780/ is a kubernetes API host which I get from kubectl config view -o jsonpath="{.clusters[?(@.name=="minikube")].cluster.server}".
- minikube has only 1 node.
- fabric8io/kubernetes-client version is 4.9.1
- Java 11
I deploy this code as a Job on the same cluster as the some-pod-name-jnfen3. Here’s the 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
For some reason it can’t connect to the kubernetes API host.
How can I fix it?
UPDATE
If I don’t pass the config to the client, it gets the correct master IP and then fails with the following exception
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)
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Answer
kubectl config view -o jsonpath="{.clusters[?(@.name=="minikube")].cluster.server}" returns the relative IP. It is different for the Pod.
Not passing config will make the library find the correct IP.
Also a new service account should be created and set in the job.yaml.
The default service account doesn’t have permissions to fetch k8s entities.
Related GitHub issue