SharedIndexInformer (Fabric8 kubernetes-client) 在集群中运行时仅监视其自己命名空间的 Pod

Question

我正在尝试使用用于 Java 的优秀 Fabric8 Kubernetes 客户端（ https://github.com/fabric8io/kubernetes-client ）构建一个 Kubernetes 控制器。 截至目前，我使用版本4.10.3 。

为此，我正在构建一个SharedIndexInformer来正确监视集群发出的资源事件。 我将在这里以 Pod 为资源示例。

所以SharedIndexInformer是按照这段代码构建的：

SharedIndexInformer<Pod> sharedIndexInformer = kubernetesClient.informers().sharedIndexInformerFor(
                objectClass,
                objectClassList,
                10 * 60 * 1000);

接下来，很多代码来附加事件处理程序，启动索引器，有一个协调循环等等。

当从我的本地机器启动时，索引器工作得很好，我看到所有的 pod 都被列出来了。 但是，当我在集群中的 pod 上运行它时（正确定义了 RBAC），我只能看到运行 pod 的命名空间的 pod。

我在 pod 中明确检查，使用kubectl ，关联的服务帐户能够列出集群中的所有 pod，而不仅仅是在当前命名空间中。

我错过了什么？

在此先感谢您的帮助！

Answer 1

我认为这是由于KubernetesClient在 Kubernetes Cluster 外部或Pod内部创建它的Config的方式不同。 在前一种情况下， KubernetesClient通常从您的~/.kube/config读取，并且连接信息（例如令牌和命名空间）是从您的~/.kube/config文件中的当前上下文中~/.kube/config 。

但是，当KubernetesClient在 Pod 内时； 它从加载的ServiceAccount获取连接Config信息，请参阅Config.java 。 不记名令牌从/var/run/secrets/kubernetes.io/serviceaccount/token选取，用于命名空间 API 操作的默认命名空间从/var/run/secrets/kubernetes.io/serviceaccount/namespace选取。 您可以在Kubernetes Docs: Accessing API from a Pod 中找到更多相关信息。 我认为KubernetesClient在加载Config时正在选择这个命名空间。

我认为KubernetesClient没有正确处理这种情况。 这应该在那里修复。 那里已经有一个问题： https : //github.com/fabric8io/kubernetes-client/issues/2514

我不确定现在的告密者是否可以检测到他们是在集群内还是在集群外（这只有在我们加载Config时才知道）。 现在，informers 提供了使用OperationContext指定命名空间的方法：

SharedInformerFactory sharedInformerFactory = client.informers();
SharedIndexInformer<Pod> podInformer = sharedInformerFactory.sharedIndexInformerFor(
        Pod.class,
        PodList.class,
        new OperationContext().withNamespace("default"),
        30 * 1000L);

也许为了覆盖从ServiceAccount加载的这个命名空间，我们可以允许设置null命名空间：

SharedIndexInformer<Pod> podInformer = sharedInformerFactory.sharedIndexInformerFor(
        Pod.class,
        PodList.class,
        new OperationContext().withNamespace(null), // -> Doesn't work; Ideally should Watch in all namespaces,
        30 * 1000L);

更新：

潜在问题似乎已在v4.13.0中解决。 我已经在这个演示项目中对此进行了测试： https : //github.com/r0haaaan/fabric8-kubernetes-java-informer-in-pod 。 它在项目中运行 SharedIndexInformers 并使用Kubernetes Maven Plugin部署到 Kubernetes。 当我检查日志时，我可以看到似乎列出了所有 pod：

fabric8-kubernetes-java-informers-in-pod : $ mvn k8s:log
[INFO] Scanning for projects...
[INFO] 
[INFO] --------< org.example:fabric8-kubernetes-java-informers-in-pod >--------
[INFO] Building fabric8-kubernetes-java-informers-in-pod 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- kubernetes-maven-plugin:1.0.2:log (default-cli) @ fabric8-kubernetes-java-informers-in-pod ---
[INFO] k8s: Using Kubernetes at https://192.168.39.24:8443/ in namespace default with manifest /home/rohaan/work/repos/fabric8-kubernetes-java-informers-in-pod/target/classes/META-INF/jkube/kubernetes.yml 
[INFO] k8s: Using namespace: default
[INFO] k8s: Watching pods with selector LabelSelector(matchExpressions=[], matchLabels={app=fabric8-kubernetes-java-informers-in-pod, provider=jkube, group=org.example}, additionalProperties={}) waiting for a running pod...
[INFO] k8s:  [NEW] fabric8-kubernetes-java-informers-in-pod-6f957b6b59-tpbgd status: Running Ready
[INFO] k8s:  [NEW] Tailing log of pod: fabric8-kubernetes-java-informers-in-pod-6f957b6b59-tpbgd
[INFO] k8s:  [NEW] Press Ctrl-C to stop tailing the log
[INFO] k8s:  [NEW] 
[INFO] k8s: Starting the Java application using /opt/jboss/container/java/run/run-java.sh ...
[INFO] k8s: INFO exec  java -javaagent:/usr/share/java/jolokia-jvm-agent/jolokia-jvm.jar=config=/opt/jboss/container/jolokia/etc/jolokia.properties -javaagent:/usr/share/java/prometheus-jmx-exporter/jmx_prometheus_javaagent.jar=9779:/opt/jboss/container/prometheus/etc/jmx-exporter-config.yaml -XX:+UseParallelOldGC -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MaxMetaspaceSize=100m -XX:+ExitOnOutOfMemoryError -cp "." -jar /deployments/fabric8-kubernetes-java-informers-in-pod-1.0-SNAPSHOT-jar-with-dependencies.jar  
[INFO] k8s: SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
[INFO] k8s: SLF4J: Defaulting to no-operation (NOP) logger implementation
[INFO] k8s: SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
[INFO] k8s: WARNING: An illegal reflective access operation has occurred
[INFO] k8s: WARNING: Illegal reflective access by org.jolokia.util.ClassUtil (file:/usr/share/java/jolokia-jvm-agent/jolokia-jvm.jar) to constructor sun.security.x509.X500Name(java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String)
[INFO] k8s: WARNING: Please consider reporting this to the maintainers of org.jolokia.util.ClassUtil
[INFO] k8s: WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
[INFO] k8s: WARNING: All illegal access operations will be denied in a future release
[INFO] k8s: Nov 10, 2020 5:37:50 PM io.fabric8.testing.SimpleSharedInformerRun main
[INFO] k8s: INFO: k8s.getConfiguration().getNamespace(): default
[INFO] k8s: I> No access restrictor found, access to any MBean is allowed
[INFO] k8s: Jolokia: Agent started with URL https://172.17.0.6:8778/jolokia/
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: default/fabric8-kubernetes-java-informers-in-pod-6f957b6b59-tpbgd
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: istio-system/istio-ingressgateway-64cfb9d44b-kk5ft
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: istio-system/istiod-7684b696d6-fhzwt
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/coredns-f9fd979d6-g4htj
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/etcd-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/kube-apiserver-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/kube-controller-manager-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/kube-proxy-tpsrg
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/kube-scheduler-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/metrics-server-d9b576748-4w6jz
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: kube-system/storage-provisioner
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onAdd
[INFO] k8s: INFO: ADDED: rokumar/multi-container-pod
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: default/fabric8-kubernetes-java-informers-in-pod-6f957b6b59-tpbgd
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: istio-system/istio-ingressgateway-64cfb9d44b-kk5ft
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: istio-system/istiod-7684b696d6-fhzwt
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/coredns-f9fd979d6-g4htj
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/etcd-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/kube-apiserver-minikube
[INFO] k8s:  [NEW] fabric8-kubernetes-java-informers-in-pod-6f957b6b59-tpbgd status: Running Ready
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/kube-controller-manager-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/kube-proxy-tpsrg
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/kube-scheduler-minikube
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/metrics-server-d9b576748-4w6jz
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: kube-system/storage-provisioner
[INFO] k8s: Nov 10, 2020 5:37:52 PM io.fabric8.testing.SimpleSharedInformerRun$1 onUpdate
[INFO] k8s: INFO: UPDATED: rokumar/multi-container-pod