kubernetes 添加node
韶弘壮
前置条件
1. 参考 kubernetes 权威指南 从一个简单例子开始 先部署 master
2. 部署 kubernetes 部署本地dns
3. 部署 kubernetes 部署flannel
说明
centos上已经部署好了 master , 虚拟机 ip 192.168.255.130， kubernetes是 yum安装的，版本为 1.5.2
打算在 ubuntu 16.04 上 部署个 node.， 虚拟机ip 192.168.255.129
安装kubernetes
node 只要 kubelet 和 kube-proxy 2个进程就行了。
把它们 scp 到 ubuntu /usr/bin 目录即可， 参考
/usr/bin # scp kube-proxy wangjunsheng@192.168.255.129:/home/wangjunsheng/kubernetes/config
/usr/bin # scp kubelet wangjunsheng@192.168.255.129:/home/wangjunsheng/kubernetes/config 然后在ubuntu, sudo mv kubelet 和 kube-proxy 到 /usr/bin 目录
写给自己的 emacs 下打开文件参考
(opo "/sudo:localhost:/lib/systemd/system/kube-proxy.service")
(opo "/sudo:localhost:/lib/systemd/system/kubelet.service")新建它们的启动配置文件
/lib/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
ExecStart=/usr/bin/kube-proxy \
--hostname-override=192.168.255.130 \
--master=http://192.168.255.130:8080 \
--logtostderr=true
Restart=on-failure
[Install]
WantedBy=multi-user.target
/lib/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service
[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/usr/bin/kubelet \
--hostname-override=192.168.255.130 \
--api-servers=http://192.168.255.130:8080 \
--cluster-dns=10.254.0.2 \
--cluster-domain=cluster.local \
--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest\
--logtostderr=true
Restart=on-failure
KillMode=process
[Install]
WantedBy=multi-user.target
systemctl daemon-reload
systemctl start kubelet
systemctl start kube-proxy注意 把 ip 改成适合自己的。 10.254.0.2 是我部署的dns的 集群ip
注意: kube-proxy 和 kubelet 的 --hostname-override=192.168.255.129 必须完全一致，且是正确的虚拟机ip。
我第一次填错了ip，结果 kubectl logs 或 exec 时总是出错，怎么也找不到原因。
可能的报错
kub exec kubia-n8snl env
error: unable to upgrade connection: pod does not existpod does not exist 其实是 kubelet 反馈的错误。kube-apiserver 已经找到了然后下发给node，node反馈找不到这个po。当然找不到啦，我的ip配置错了，问了错误的node。我刚好把2个node的 hostname-override 配反了，所以就提示找不到pod。如果不是配反，而是配错，估计就是报类似下面的错误。无法建立连接。
kubectl exec -ti myweb-99lfw -- /bin/bash
Error from server: error dialing backend: dial tcp 192.168.255.129:10250: getsockopt: connection refused首先确定它们配对了，还是不行的话 kubectl delete no 后，再重启 所有的进程 : master的3个进程和 node的 kube-proxy kubelet
可以通过 kubectl get svc 查看
~/kubernetes/docker $ kubectl get svc --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.254.0.1 <none> 443/TCP 18d
kube-system kube-dns ClusterIP 10.254.0.2 <none> 53/UDP,53/TCP 12d
可以查看到新部署上去的node
kubectl get node
NAME STATUS ROLES AGE VERSION
127.0.0.1 Ready <none> 18d v1.5.2
192.168.255.130 Ready <none> 18h v1.5.2
安装指定版本的docker
1.5.2 的kubernete 无法驾驭 我已经装好的 18.09的 docker-ce， 查看 centos 下 docker 版本号 (docker -v) 发现是1.13.1的。
我在ubuntu下安装 1.13.1版本的 docker
卸载原先的，我装的 18.09的ce，需要如下卸载
sudo apt-get purge docker-ce如果你装的不是ce, 则 sudo apt-get remove docker 应该就可以了
然后到下面这个链接找到适合k8s的发行版本，我要找 1.13.1 的，翻了一页才找到(下面有个 next 翻页按钮)
https://github.com/moby/moby/releases
Linux 64bits tgz: https://get.docker.com/builds/Linux/x86_64/docker-1.13.1.tgzwget https://get.docker.com/builds/Linux/x86_64/docker-1.13.1.tgz
sudo tar --strip-components=1 -xvzf docker-1.13.1.tgz -C /usr/local/bin
制作开机启动
写给自己的 emacs 参考
(opo "/sudo:localhost:/lib/systemd/system/docker.service")/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
BindsTo=containerd.service
After=network-online.target firewalld.service
Wants=network-online.target
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
EnvironmentFile=-/run/flannel/subnet.env
ExecStart=/usr/local/bin/dockerd -H unix://\
--selinux-enabled=false \
--insecure-registry=gcr.io \
--bip=${FLANNEL_SUBNET} \
--mtu=${FLANNEL_MTU}
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Comment TasksMax if your systemd version does not supports it.
# Only systemd 226 and above support this option.
TasksMax=infinity
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
[Install]
WantedBy=multi-user.target
部署个例子试试
参考 kubernetes 部署redis 集群 guestbook
就用这个例子
kubectl create -f redis-master-rc.yaml -f redis-master-svc.yaml
kubectl create -f redis-slave-rc.yaml -f redis-slave-svc.yaml
kubectl create -f fe-rc.yaml -f fe-svc.yaml 然后看看 部署情况
~/k8s/demo2 # kubectl get po
NAME READY STATUS RESTARTS AGE
frontend-g0x36 0/1 ContainerCreating 0 6s
frontend-t2q86 1/1 Running 0 6s
frontend-v86jn 0/1 ContainerCreating 0 6s
redis-master-p23sc 1/1 Running 0 44m
redis-slave-vm5c6 1/1 Running 0 19skubectl create -f redis-master-rc.yaml -f redis-master-svc.yaml 再看看 pod 的具体情况， 如果部署不成功可以使用 kubectl describe pod pod_name 来查看详细原因
~/k8s/demo2 # kubectl describe po frontend-v86jn
Name: frontend-v86jn
Namespace: default
Node: 192.168.255.130/192.168.255.130
Start Time: Tue, 15 Jan 2019 10:32:00 +0800
Labels: name=frontend
Status: Pending
IP:
Controllers: ReplicationController/frontend
Containers:
php-redis:
Container ID:
Image: kubeguide/guestbook-php-frontend
Image ID:
Port: 80/TCP
State: Waiting
Reason: ContainerCreating
Ready: False
Restart Count: 0
Volume Mounts: <none>
Environment Variables:
GET_HOSTS_FROM: env
Conditions:
Type Status
Initialized True
Ready False
PodScheduled True
No volumes.
QoS Class: BestEffort
Tolerations: <none>
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
3m 3m 1 {default-scheduler } Normal Scheduled Successfully assigned frontend-v86jn to 192.168.255.130
3m 3m 1 {kubelet 192.168.255.130} spec.containers{php-redis} Normal Pulling pulling image "kubeguide/guestbook-php-frontend"pull image是比较耗时的，再等等，就都ok了
再看看 node 的部署情况，如下可以看到 master 在这个node部署了2个pod : frontend-v86jn 和 redis-master-p23sc
~/kubernetes/docker $ kub describe node 192.168.255.130
Name: 192.168.255.130
Roles: <none>
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=192.168.255.130
Annotations: volumes.kubernetes.io/controller-managed-attach-detach=true
CreationTimestamp: Mon, 14 Jan 2019 15:13:06 +0800
Taints: <none>
Unschedulable: false
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
OutOfDisk False Tue, 15 Jan 2019 10:46:36 +0800 Mon, 14 Jan 2019 17:53:02 +0800 KubeletHasSufficientDisk kubelet has sufficient disk space available
MemoryPressure False Tue, 15 Jan 2019 10:46:36 +0800 Mon, 14 Jan 2019 15:13:14 +0800 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Tue, 15 Jan 2019 10:46:36 +0800 Mon, 14 Jan 2019 15:13:14 +0800 KubeletHasNoDiskPressure kubelet has no disk pressure
Ready True Tue, 15 Jan 2019 10:46:36 +0800 Mon, 14 Jan 2019 17:53:12 +0800 KubeletReady kubelet is posting ready status. AppArmor enabled
Addresses:
LegacyHostIP: 192.168.255.130
InternalIP: 192.168.255.130
Hostname: 192.168.255.130
Capacity:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 3
memory: 1513724Ki
pods: 110
Allocatable:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 3
memory: 1513724Ki
pods: 110
System Info:
Machine ID: c7c3c86052714ab682a8d009e1afb546
System UUID: 94FE4D56-E298-8159-8525-8C52FFBB9417
Boot ID: 112639ee-c30f-4bdb-9891-cc6afd7db108
Kernel Version: 4.4.0-139-generic
OS Image: Ubuntu 16.04 LTS
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://1.13.1
Kubelet Version: v1.5.2
Kube-Proxy Version: v1.5.2
ExternalID: 192.168.255.130
Non-terminated Pods: (2 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits
--------- ---- ------------ ---------- --------------- -------------
default frontend-v86jn 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default redis-master-p23sc 0 (0%) 0 (0%) 0 (0%) 0 (0%)
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
CPU Requests CPU Limits Memory Requests Memory Limits
------------ ---------- --------------- -------------
0 (0%) 0 (0%) 0 (0%) 0 (0%)
Events: <none>
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