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初始化kubeadm时出现以下错误。kubeadm reset在做之前我也尝试过命令kubadm init。Kubelet 也在运行，我使用的命令是systemctl enable kubelet && systemctl start kubelet. 以下是执行 kubeadm init 后的日志

[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[init] Using Kubernetes version: v1.8.2
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks
[preflight] WARNING: Connection to "https://192.168.78.48:6443" uses proxy "http://user:pwd@192.168.78.15:3128/". If that is not intended, adjust your proxy settings
[preflight] WARNING: Running with swap on is not supported. Please disable swap or set kubelet's --fail-swap-on flag to false.
[preflight] Starting the kubelet service
[kubeadm] WARNING: starting in 1.8, tokens expire after 24 hours by default (if you require a non-expiring token use --token-ttl 0)
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [steller.india.com kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.140.48]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests"
[init] This often takes around a minute; or longer if the control plane images have to be pulled.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz' failed with error: Get http://localhost:10255/healthz: dial tcp [::1]:10255: getsockopt: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz' failed with error: Get http://localhost:10255/healthz: dial tcp [::1]:10255: getsockopt: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz' failed with error: Get http://localhost:10255/healthz: dial tcp [::1]:10255: getsockopt: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz/syncloop' failed with error: Get http://localhost:10255/healthz/syncloop: dial tcp [::1]:10255: getsockopt: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz/syncloop' failed with error: Get http://localhost:10255/healthz/syncloop: dial tcp [::1]:10255: getsockopt: connection refused.

以下是输出journalctl -u kubelet

-- Logs begin at Thu 2017-11-02 16:20:50 IST, end at Fri 2017-11-03 17:11:12 IST. --
Nov 03 16:36:48 steller.india.com systemd[1]: Started kubelet: The Kubernetes Node Agent.
Nov 03 16:36:48 steller.india.com systemd[1]: Starting kubelet: The Kubernetes Node Agent...
Nov 03 16:36:48 steller.india.com kubelet[52511]: I1103 16:36:48.998467   52511 feature_gate.go:156] feature gates: map[]
Nov 03 16:36:48 steller.india.com kubelet[52511]: I1103 16:36:48.998532   52511 controller.go:114] kubelet config controller: starting controller
Nov 03 16:36:48 steller.india.com kubelet[52511]: I1103 16:36:48.998536   52511 controller.go:118] kubelet config controller: validating combination of defaults and flag
Nov 03 16:36:49 steller.india.com kubelet[52511]: I1103 16:36:49.837248   52511 client.go:75] Connecting to docker on unix:///var/run/docker.sock
Nov 03 16:36:49 steller.india.com kubelet[52511]: I1103 16:36:49.837282   52511 client.go:95] Start docker client with request timeout=2m0s
Nov 03 16:36:49 steller.india.com kubelet[52511]: W1103 16:36:49.839719   52511 cni.go:196] Unable to update cni config: No networks found in /etc/cni/net.d
Nov 03 16:36:49 steller.india.com systemd[1]: kubelet.service: main process exited, code=exited, status=1/FAILURE
Nov 03 16:36:49 steller.india.com kubelet[52511]: I1103 16:36:49.846959   52511 feature_gate.go:156] feature gates: map[]
Nov 03 16:36:49 steller.india.com kubelet[52511]: W1103 16:36:49.847216   52511 server.go:289] --cloud-provider=auto-detect is deprecated. The desired cloud provider sho
Nov 03 16:36:49 steller.india.com kubelet[52511]: error: failed to run Kubelet: unable to load bootstrap kubeconfig: stat /etc/kubernetes/bootstrap-kubelet.conf: no such
Nov 03 16:36:49 steller.india.com systemd[1]: Unit kubelet.service entered failed state.
Nov 03 16:36:49 steller.india.com systemd[1]: kubelet.service failed.
Nov 03 16:37:00 steller.india.com systemd[1]: kubelet.service holdoff time over, scheduling restart.
Nov 03 16:37:00 steller.india.com systemd[1]: Started kubelet: The Kubernetes Node Agent.
Nov 03 16:37:00 steller.india.com systemd[1]: Starting kubelet: The Kubernetes Node Agent...
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.134702   52975 feature_gate.go:156] feature gates: map[]
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.134763   52975 controller.go:114] kubelet config controller: starting controller
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.134767   52975 controller.go:118] kubelet config controller: validating combination of defaults and flag
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.141273   52975 client.go:75] Connecting to docker on unix:///var/run/docker.sock
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.141364   52975 client.go:95] Start docker client with request timeout=2m0s
Nov 03 16:37:00 steller.india.com kubelet[52975]: W1103 16:37:00.143023   52975 cni.go:196] Unable to update cni config: No networks found in /etc/cni/net.d
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.149537   52975 feature_gate.go:156] feature gates: map[]
Nov 03 16:37:00 steller.india.com kubelet[52975]: W1103 16:37:00.149780   52975 server.go:289] --cloud-provider=auto-detect is deprecated. The desired cloud provider sho
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.179873   52975 certificate_manager.go:361] Requesting new certificate.
Nov 03 16:37:00 steller.india.com kubelet[52975]: E1103 16:37:00.180392   52975 certificate_manager.go:284] Failed while requesting a signed certificate from the master:
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.181404   52975 manager.go:149] cAdvisor running in container: "/sys/fs/cgroup/cpu,cpuacct/system.slice/k
Nov 03 16:37:00 steller.india.com kubelet[52975]: W1103 16:37:00.223876   52975 manager.go:157] unable to connect to Rkt api service: rkt: cannot tcp Dial rkt api servic
Nov 03 16:37:00 steller.india.com kubelet[52975]: W1103 16:37:00.224005   52975 manager.go:166] unable to connect to CRI-O api service: Get http://%2Fvar%2Frun%2Fcrio.so
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.262573   52975 fs.go:139] Filesystem UUIDs: map[17856e0b-777f-4065-ac97-fb75d7a1e197:/dev/dm-1 2dc6a878-
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.262604   52975 fs.go:140] Filesystem partitions: map[/dev/sdb:{mountpoint:/D major:8 minor:16 fsType:xfs
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.268969   52975 manager.go:216] Machine: {NumCores:56 CpuFrequency:2600000 MemoryCapacity:540743667712 Hu
Nov 03 16:37:00 steller.india.com kubelet[52975]: 967295 Mtu:1500} {Name:eno49 MacAddress:14:02:ec:82:57:30 Speed:10000 Mtu:1500} {Name:eno50 MacAddress:14:02:ec:82:57:3
Nov 03 16:37:00 steller.india.com kubelet[52975]: evel:1} {Size:262144 Type:Unified Level:2}]} {Id:13 Threads:[12 40] Caches:[{Size:32768 Type:Data Level:1} {Size:32768
Nov 03 16:37:00 steller.india.com kubelet[52975]: s:[26 54] Caches:[{Size:32768 Type:Data Level:1} {Size:32768 Type:Instruction Level:1} {Size:262144 Type:Unified Level:
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.270145   52975 manager.go:222] Version: {KernelVersion:3.10.0-229.14.1.el7.x86_64 ContainerOsVersion:Cen
Nov 03 16:37:00 steller.india.com kubelet[52975]: I1103 16:37:00.271263   52975 server.go:422] --cgroups-per-qos enabled, but --cgroup-root was not specified.  defaultin
Nov 03 16:37:00 steller.india.com kubelet[52975]: error: failed to run Kubelet: Running with swap on is not supported, please disable swap! or set --fail-swap-on flag to
Nov 03 16:37:00 steller.india.com systemd[1]: kubelet.service: main process exited, code=exited, status=1/FAILURE
Nov 03 16:37:00 steller.india.com systemd[1]: Unit kubelet.service entered failed state.
Nov 03 16:37:00 steller.india.com systemd[1]: kubelet.service failed.

4

6 回答 6

20

只需禁用机器中的交换即可。sudo swapoff -a

于 2017-12-09T10:27:09.403 回答
8

一些 Kubernetes 部署需要交换

一般来说，官方的要求是禁用swap。

原因？Kubernetes 尚不支持。IMO 他们要求您禁用交换以防止多节点集群工作负载转移的问题。

但是，我有一个有效的用例——我正在开发一个本地产品，linux 发行版，包含在 kubeadm 中。没有设计水平缩放。为了在机会性内存峰值中存活并仍然起作用（但速度很慢），我绝对需要 swap。

kubeadm在启用交换的情况下安装：

  1. 创建一个包含/etc/systemd/system/kubelet.service.d/20-allow-swap.conf内容的文件：

    [Service]
Environment="KUBELET_EXTRA_ARGS=--fail-swap-on=false"

  2. 跑

    sudo systemctl daemon-reload

  3. kubeadm用标志初始化--ignore-preflight-errors=Swap

    kubeadm init --ignore-preflight-errors=Swap
于 2020-06-02T18:03:50.890 回答
3

sudo swapoff -a 在重新启动后不会持续存在。

您可以通过在 /etc/fstab 文件中注释掉（在行前添加 #）交换条目来在重新启动后禁用交换。它将防止交换分区在重新启动后自动挂载。

脚步：

  1. 打开文件 /etc/fstab

  2. 在下面寻找一行

    # 安装期间交换在 /dev/sda5 上

    UUID=e7bf7d6e-e90d-4a96-91db-7d5f282f9363 无交换 sw 0 0

  3. 用# 注释掉上面的行并保存。它应该如下所示

    # 安装期间交换在 /dev/sda5 上

    #UUID=e7bf7d6e-e90d-4a96-91db-7d5f282f9363 无交换 sw 0 0

  4. 重新启动系统或为当前会话执行“sudo swapoff -a”以避免重新启动。

于 2019-06-23T11:34:42.060 回答
1

看起来你已经在你的服务器上启用了交换，你可以禁用它并重新运行 init 命令。

error: failed to run Kubelet: Running with swap on is not supported, please disable swap! or set --fail-swap-on flag to

这是在 centos 中禁用交换的步骤https://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-swap-removing.html

于 2017-11-03T13:29:33.910 回答
0

在 Ubuntu 上禁用 SWAP 并使其持久化：

sudo swapoff -a && sudo sed -i '/swap/d' /etc/fstab

第二个命令将通过注释掉文件/etc/fstab中的 SWAP 行来永久禁用 SWAP

于 2021-09-06T22:41:57.643 回答
0

我猜不同的用户会出于不同的原因提出这个问题，所以我会在这里添加额外的解释。

最快和最安全的解决方案是禁用交换 - 就像@Jossef_Harush 共享的链接中提到的那样，这也是 K8S 推荐的。
但正如他也提到的 - 一些工作负载需要更深入的内存管理。

如果您因为有意启用交换而遇到上述错误- 我建议在考虑启用交换之前阅读有关驱逐最终用户 Pod 的内容：

如果 kubelet 无法在节点上回收足够的资源，则 kubelet 开始驱逐 Pod。

kubelet 首先根据 Pod 对饥饿资源的使用是否超过请求，然后根据优先级，然后根据相对于 Pod 调度请求的饥饿计算资源的消耗来对 Pod 进行驱逐排名。

因此，kubelet 按以下顺序排列和驱逐 Pod：

  • BestEffort 或 Burstable Pod，其对缺乏资源的使用超过其请求。此类 pod 按优先级排序，然后使用高于请求。

  • 使用率低于请求的保证 pod 和 Burstable pod 最后被驱逐。Guaranteed Pod 仅在为所有容器指定请求和限制并且它们相等时才得到保证。这样的 Pod 保证不会因为另一个 Pod 的资源消耗而被驱逐。如果系统守护进程（例如 kubelet、docker 和 journald）消耗的资源多于通过 system-reserved 或 kube-reserved 分配保留的资源，并且节点只有 Guaranteed 或 Burstable Pod 使用的请求数少于剩余请求数，则该节点必须选择驱逐这样的 Pod 以保持节点稳定性并限制意外消耗对其他 Pod 的影响。在这种情况下，它将选择首先驱逐最低优先级的 pod。

确保您也熟悉：

1 ) 3 个 qos 类- 确保您的高优先级工作负载使用 Guaranteed（或至少 Burstable）类运行。

2) Pod 优先级和抢占。

于 2020-11-16T11:32:52.553 回答