kubernetes - kube-proxy不更新iptables

Question

我有一个运行了8天的k8s集群，然后它开始表现异常。

我的具体问题是关于kube-proxy的。 kube-proxy没有更新iptables。

从kube-proxy日志中，我可以看到它无法连接到kubernetes-apiserver(在我的情况下，连接是kube-prxy-> Haproxy-> k8s API服务器)。但是 pods 显示为“正在运行”。

问题:如果无法向apiserver注册事件，我希望kube-proxy pod能够关闭。

如何通过 Activity 探针实现此行为？

注意:杀死 pod 后，kube-proxy可以正常工作。

库贝代理日志

sudo docker logs 1de375c94fd4 -f
W0910 15:18:22.091902       1 server.go:195] WARNING: all flags other than --config, --write-config-to, and --cleanup are deprecated. Please begin using a config file ASAP.
I0910 15:18:22.091962       1 feature_gate.go:226] feature gates: &{{} map[]}
time="2018-09-10T15:18:22Z" level=warning msg="Running modprobe ip_vs failed with message: `modprobe: ERROR: ../libkmod/libkmod.c:586 kmod_search_moddep() could not open moddep file '/lib/modules/4.15.0-33-generic/modules.dep.bin'\nmodprobe: WARNING: Module ip_vs not found in directory /lib/modules/4.15.0-33-generic`, error: exit status 1"
time="2018-09-10T15:18:22Z" level=error msg="Could not get ipvs family information from the kernel. It is possible that ipvs is not enabled in your kernel. Native loadbalancing will not work until this is fixed."
I0910 15:18:22.185086       1 server.go:409] Neither kubeconfig file nor master URL was specified. Falling back to in-cluster config.
I0910 15:18:22.186885       1 server_others.go:140] Using iptables Proxier.
W0910 15:18:22.438408       1 server.go:601] Failed to retrieve node info: nodes "$(node_name)" not found
W0910 15:18:22.438494       1 proxier.go:306] invalid nodeIP, initializing kube-proxy with 127.0.0.1 as nodeIP
I0910 15:18:22.438595       1 server_others.go:174] Tearing down inactive rules.
I0910 15:18:22.861478       1 server.go:444] Version: v1.10.2
I0910 15:18:22.867003       1 conntrack.go:98] Set sysctl 'net/netfilter/nf_conntrack_max' to 2883584
I0910 15:18:22.867046       1 conntrack.go:52] Setting nf_conntrack_max to 2883584
I0910 15:18:22.867267       1 conntrack.go:83] Setting conntrack hashsize to 720896
I0910 15:18:22.893396       1 conntrack.go:98] Set sysctl 'net/netfilter/nf_conntrack_tcp_timeout_established' to 86400
I0910 15:18:22.893505       1 conntrack.go:98] Set sysctl 'net/netfilter/nf_conntrack_tcp_timeout_close_wait' to 3600
I0910 15:18:22.893737       1 config.go:102] Starting endpoints config controller
I0910 15:18:22.893749       1 controller_utils.go:1019] Waiting for caches to sync for endpoints config controller
I0910 15:18:22.893742       1 config.go:202] Starting service config controller
I0910 15:18:22.893765       1 controller_utils.go:1019] Waiting for caches to sync for service config controller
I0910 15:18:22.993904       1 controller_utils.go:1026] Caches are synced for endpoints config controller
I0910 15:18:22.993921       1 controller_utils.go:1026] Caches are synced for service config controller
W0910 16:13:28.276082       1 reflector.go:341] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: watch of *core.Endpoints ended with: very short watch: k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Unexpected watch close - watch lasted less than a second and no items received
W0910 16:13:28.276083       1 reflector.go:341] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: watch of *core.Service ended with: very short watch: k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Unexpected watch close - watch lasted less than a second and no items received
E0910 16:13:29.276678       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Endpoints: Get https://127.0.0.1:6553/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:29.276677       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Service: Get https://127.0.0.1:6553/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:30.277201       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Endpoints: Get https://127.0.0.1:6553/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:30.278009       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Service: Get https://127.0.0.1:6553/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:31.277723       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Endpoints: Get https://127.0.0.1:6553/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:31.278574       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Service: Get https://127.0.0.1:6553/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:32.278197       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Endpoints: Get https://127.0.0.1:6553/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:32.279134       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Service: Get https://127.0.0.1:6553/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:33.278684       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Endpoints: Get https://127.0.0.1:6553/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused
E0910 16:13:33.279587       1 reflector.go:205] k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion/factory.go:86: Failed to list *core.Service: Get https://127.0.0.1:6553/api/v1/services?limit=500&resourceVersion=0: dial tcp 127.0.0.1:6553: getsockopt: connection refused

Answer 1

Question: I am expecting kube-proxy pod to be down if it is not able to register with apiserver for events.

不应该使用kube-proxy。它侦听kube-apiserver上的事件，并在发生更改/部署时执行所需的任何操作。我可以想到的理由是，它可能是在缓存信息以使系统上的iptables保持一致。 Kubernetes的设计方式是，如果您的master / kube-apiserver /或master组件出现故障，那么流量仍应流向节点，而不会造成停机。

How do I achieve this behavior via liveness probes?

您始终可以将 Activity 探针添加到 kube-proxy DaemonSet中，但是不建议这样做:

spec:
  containers:
  - command:
    - /usr/local/bin/kube-proxy
    - --config=/var/lib/kube-proxy/config.conf
    image: k8s.gcr.io/kube-proxy-amd64:v1.11.2
    imagePullPolicy: IfNotPresent
    name: kube-proxy
    resources: {}
    securityContext:
      privileged: true
    livenessProbe:
      exec:
        command:
          - curl <apiserver>:10256/healthz
      initialDelaySeconds: 5
      periodSeconds: 5

确保在kube-apiserver上启用了 --healthz-port。