kubeadm是Kubernetes官方提供的用于快速安装Kubernetes集群的工具,伴随Kubernetes每个版本的发布都会同步更新,kubeadm会对集群配置方面的一些实践做调整,通过实验kubeadm可以学习到Kubernetes官方在集群配置上一些新的最佳实践。
在Kubernetes的文档Using kubeadm to Create a Cluster中已经给出了目前kubeadm的主要特性已经处于beta状态了,在2018年将进入GA状态,说明kubeadm离可以在生产环境中使用的距离越来越近了。
当然我们线上稳定运行的Kubernetes集群是使用ansible以二进制形式的部署的高可用集群,这里体验Kubernetes 1.11中的kubeadm是为了跟随官方对集群初始化和配置方面的最佳实践,进一步完善我们的ansible部署脚本。
1.准备
1.1系统配置
在安装之前,需要先做如下准备。两台CentOS 7.4主机如下:
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cat /etc/hosts
192.168.61.11 node1
192.168.61.12 node2
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如果各个主机启用了防火墙,需要开放Kubernetes各个组件所需要的端口,可以查看Installing kubeadm中的"Check required ports"一节。
这里简单起见在各节点禁用防火墙:
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systemctl stop firewalld
systemctl disable firewalld
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禁用SELINUX:
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vi /etc/selinux/config
SELINUX=disabled
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创建/etc/sysctl.d/k8s.conf文件,添加如下内容:
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net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
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执行命令使修改生效。
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modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf
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1.2安装Docker
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yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
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查看当前的Docker版本:
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yum list docker-ce.x86_64 --showduplicates |sort -r
docker-ce.x86_64 18.06.0.ce-3.el7 docker-ce-stable
docker-ce.x86_64 18.03.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 18.03.0.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.12.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.12.0.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.09.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.09.0.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.06.2.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.06.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.06.0.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.03.2.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.03.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.03.0.ce-1.el7.centos docker-ce-stable
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Kubernetes 1.10已经针对Docker的1.11, 1.12, 1.13.1和17.03等版本做了验证,需要注意Kubernetes 1.10最低支持的Docker版本是1.11。
我们这里在各节点安装docker的17.03.2版本。
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yum makecache fast
yum install -y --setopt=obsoletes=0 \
docker-ce-17.03.2.ce-1.el7.centos \
docker-ce-selinux-17.03.2.ce-1.el7.centos
systemctl start docker
systemctl enable docker
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Docker从1.13版本开始调整了默认的防火墙规则,禁用了iptables filter表中FOWARD链,这样会引起Kubernetes集群中跨Node的Pod无法通信,在各个Docker节点执行下面的命令:
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iptables -P FORWARD ACCEPT
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可在docker的systemd unit文件中以ExecStartPost加入上面的命令:
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ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT
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systemctl daemon-reload
systemctl restart docker
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2.使用kubeadm部署Kubernetes
2.1 安装kubeadm和kubelet
下面在各节点安装kubeadm和kubelet:
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cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
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测试地址https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
是否可用,如果不可用需要科学上网。
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curl https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
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yum makecache fast
yum install -y kubelet kubeadm kubectl
...
Installed:
kubeadm.x86_64 0:1.11.1-0 kubectl.x86_64 0:1.11.1-0 kubelet.x86_64 0:1.11.1-0
Dependency Installed:
cri-tools.x86_64 0:1.11.0-0 kubernetes-cni.x86_64 0:0.6.0-0 socat.x86_64 0:1.7.3.2-2.el7
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- 从安装结果可以看出还安装了cri-tools, kubernetes-cni, socat三个依赖:
* 官方从Kubernetes 1.9开始就将cni依赖升级到了0.6.0版本,在当前1.11中仍然是这个版本
* socat是kubelet的依赖
- 可以看出从Kubernetes 1.10开始安装了cri-tools,这是CRI(Container Runtime Interface)容器运行时接口的命令行工具
运行kubelet --help
可以看到原来kubelet的绝大多数命令行flag参数都被DEPRECATED
了,如:
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......
--address 0.0.0.0 The IP address for the Kubelet to serve on (set to 0.0.0.0 for all IPv4 interfaces and `::` for all IPv6 interfaces) (default 0.0.0.0) (DEPRECATED: This parameter should be set via the config file specified by the Kubelet's --config flag. See https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/ for more information.)
......
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而官方推荐我们使用--config
指定配置文件,并在配置文件中指定原来这些flag所配置的内容。具体内容可以查看这里Set Kubelet parameters via a config file。这也是Kubernetes为了支持动态Kubelet配置(Dynamic Kubelet Configuration)才这么做的,参考Reconfigure a Node’s Kubelet in a Live Cluster。
kubelet的配置文件必须是json或yaml格式,具体可查看这里。
Kubernetes 1.8开始要求关闭系统的Swap,如果不关闭,默认配置下kubelet将无法启动。
关闭系统的Swap方法如下:
修改 /etc/fstab 文件,注释掉 SWAP 的自动挂载,使用free -m
确认swap已经关闭。
swappiness参数调整,修改/etc/sysctl.d/k8s.conf添加下面一行:
执行sysctl -p /etc/sysctl.d/k8s.conf
使修改生效。
因为这里本次用于测试两台主机上还运行其他服务,关闭swap可能会对其他服务产生影响,所以这里修改kubelet的配置去掉这个限制。
之前的Kubernetes版本我们都是通过kubelet的启动参数--fail-swap-on=false
去掉这个限制的。前面已经分析了Kubernetes不再推荐使用启动参数,而推荐使用配置文件。
所以这里我们改成配置文件配置的形式。
查看/etc/systemd/system/kubelet.service.d/10-kubeadm.conf,看到了下面的内容:
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# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS
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上面显示kubeadm部署的kubelet的配置文件--config=/var/lib/kubelet/config.yaml
,实际去查看/var/lib/kubelet和这个config.yaml的配置文件都没有被创建。
可以猜想肯定是运行kubeadm
初始化集群时会自动生成这个配置文件,而如果我们不关闭Swap的话,第一次初始化集群肯定会失败的。
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kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
failSwapOn: false
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所以还是老老实实的回到使用kubelet的启动参数--fail-swap-on=false
去掉必须关闭Swap的限制。
修改/etc/sysconfig/kubelet,加入:
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KUBELET_EXTRA_ARGS=--fail-swap-on=false
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2.2 使用kubeadm init初始化集群
在各节点开机启动kubelet服务:
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systemctl enable kubelet.service
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接下来使用kubeadm初始化集群,选择node1作为Master Node,在node1上执行下面的命令:
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kubeadm init \
--kubernetes-version=v1.11.1 \
--pod-network-cidr=10.244.0.0/16 \
--apiserver-advertise-address=192.168.61.11
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因为我们选择flannel作为Pod网络插件,所以上面的命令指定–pod-network-cidr=10.244.0.0/16。
执行时报了下面的错误:
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[init] using Kubernetes version: v1.11.1
[preflight] running pre-flight checks
I0808 22:43:43.985513 10870 kernel_validator.go:81] Validating kernel version
I0808 22:43:43.985694 10870 kernel_validator.go:96] Validating kernel config
[preflight] Some fatal errors occurred:
[ERROR Swap]: running with swap on is not supported. Please disable swap
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
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有一个错误信息是running with swap on is not supported. Please disable swap
。因为我们决定配置failSwapOn: false
,所以重新添加–ignore-preflight-errors=Swap参数忽略这个错误,重新运行。
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kubeadm init \
--kubernetes-version=v1.11.1 \
--pod-network-cidr=10.244.0.0/16 \
--apiserver-advertise-address=192.168.61.11 \
--ignore-preflight-errors=Swap
[init] using Kubernetes version: v1.11.1
[preflight] running pre-flight checks
[WARNING Swap]: running with swap on is not supported. Please disable swap
I0808 19:09:53.569206 1866 kernel_validator.go:81] Validating kernel version
I0808 19:09:53.569323 1866 kernel_validator.go:96] Validating kernel config
[preflight/images] Pulling images required for setting up a Kubernetes cluster
[preflight/images] This might take a minute or two, depending on the speed of your internet connection
[preflight/images] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/ kubeadm-flags.env"
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[preflight] Activating the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [node1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.61.11]
[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] Generated etcd/ca certificate and key.
[certificates] Generated etcd/server certificate and key.
[certificates] etcd/server serving cert is signed for DNS names [node1 localhost] and IPs [127.0.0.1 ::1]
[certificates] Generated etcd/peer certificate and key.
[certificates] etcd/peer serving cert is signed for DNS names [node1 localhost] and IPs [192.168.61.11 127.0.0.1 ::1]
[certificates] Generated etcd/healthcheck-client certificate and key.
[certificates] Generated apiserver-etcd-client certificate and key.
[certificates] valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/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 might take a minute or longer if the control plane images have to be pulled
[apiclient] All control plane components are healthy after 44.502604 seconds
[uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.11" in namespace kube-system with the configuration for the kubelets in the cluster
[markmaster] Marking the node node1 as master by adding the label "node-role.kubernetes.io/master=''"
[markmaster] Marking the node node1 as master by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "node1" as an annotation
[bootstraptoken] using token: 1v7mpt.52vss1lhp4v6eqke
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
Your Kubernetes master has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
You can now join any number of machines by running the following on each node
as root:
kubeadm join 192.168.61.11:6443 --token 1v7mpt.52vss1lhp4v6eqke --discovery-token-ca-cert-hash sha256:b7161b219514e5943cf4dfd5e20851fb1dc98185b94bf600356cd2a3a4a91782
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上面记录了完成的初始化输出的内容,根据输出的内容基本上可以看出手动初始化安装一个Kubernetes集群所需要的关键步骤。
其中有以下关键内容:
[kubelet]
生成kubelet的配置文件"/var/lib/kubelet/config.yaml"
[certificates]
生成相关的各种证书
[kubeconfig]
接下来是生成证书和相关的kubeconfig文件,这个目前我们在Kubernetes 1.6 高可用集群部署也是这么做的
[bootstraptoken]
生成token记录下来,后边使用kubeadm join
往集群中添加节点时会用到
- 下面的命令是配置常规用户如何使用kubectl访问集群:
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mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
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- 最后给出了将节点加入集群的命令
kubeadm join 192.168.61.11:6443 --token 1v7mpt.52vss1lhp4v6eqke --discovery-token-ca-cert-hash sha256:b7161b219514e5943cf4dfd5e20851fb1dc98185b94bf600356cd2a3a4a91782
查看一下集群状态:
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NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health": "true"}
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确认个组件都处于healthy状态。
集群初始化如果遇到问题,可以使用下面的命令进行清理:
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kubeadm reset
ifconfig cni0 down
ip link delete cni0
ifconfig flannel.1 down
ip link delete flannel.1
rm -rf /var/lib/cni/
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2.3 安装Pod Network
接下来安装flannel network add-on:
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mkdir -p ~/k8s/
cd ~/k8s
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f kube-flannel.yml
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.extensions/kube-flannel-ds-amd64 created
daemonset.extensions/kube-flannel-ds-arm64 created
daemonset.extensions/kube-flannel-ds-arm created
daemonset.extensions/kube-flannel-ds-ppc64le created
daemonset.extensions/kube-flannel-ds-s390x created
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这里注意kube-flannel.yml这个文件里的flannel的镜像是0.10.0,quay.io/coreos/flannel:v0.10.0-amd64
如果Node有多个网卡的话,参考flannel issues 39701,目前需要在kube-flannel.yml中使用--iface
参数指定集群主机内网网卡的名称,否则可能会出现dns无法解析。需要将kube-flannel.yml下载到本地,flanneld启动参数加上--iface=<iface-name>
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......
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.10.0-amd64
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth1
......
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使用kubectl get pod --all-namespaces -o wide
确保所有的Pod都处于Running状态。
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kubectl get pod --all-namespaces -o wide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE
kube-system coredns-78fcdf6894-46nwh 1/1 Running 0 12m 10.244.0.2 node1
kube-system coredns-78fcdf6894-vf85c 1/1 Running 0 12m 10.244.0.3 node1
kube-system etcd-node1 1/1 Running 0 12m 192.168.61.11 node1
kube-system kube-apiserver-node1 1/1 Running 0 12m 192.168.61.11 node1
kube-system kube-controller-manager-node1 1/1 Running 0 12m 192.168.61.11 node1
kube-system kube-flannel-ds-amd64-2fjp6 1/1 Running 0 2m 192.168.61.11 node1
kube-system kube-proxy-gms8k 1/1 Running 0 12m 192.168.61.11 node1
kube-system kube-scheduler-node1 1/1 Running 0 11m 192.168.61.11 node1
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可以看到Kubernetes 1.11已经使用coredns替换了kube-dns
2.4 master node参与工作负载
使用kubeadm初始化的集群,出于安全考虑Pod不会被调度到Master Node上,也就是说Master Node不参与工作负载。这是因为当前的master节点node1被打上了node-role.kubernetes.io/master:NoSchedule
的污点:
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kubectl describe node node1 | grep Taint
Taints: node-role.kubernetes.io/master:NoSchedule
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因为这里搭建的是测试环境,去掉这个污点使node1参与工作负载:
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kubectl taint nodes node1 node-role.kubernetes.io/master-
node "node1" untainted
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2.5 测试DNS
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kubectl run curl --image=radial/busyboxplus:curl -i --tty
If you don't see a command prompt, try pressing enter.
[ [email protected]:/ ]$
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进入后执行nslookup kubernetes.default确认解析正常:
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nslookup kubernetes.default
Server: 10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
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2.6 向Kubernetes集群中添加Node节点
下面我们将node2这个主机添加到Kubernetes集群中,因为我们同样在node2上的kubelet的启动参数中去掉了必须关闭swap的限制,所以同样需要--ignore-preflight-errors=Swap
这个参数。
在node2上执行:
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kubeadm join 192.168.61.11:6443 --token 1v7mpt.52vss1lhp4v6eqke --discovery-token-ca-cert-hash sha256:b7161b219514e5943cf4dfd5e20851fb1dc98185b94bf600356cd2a3a4a91782 \
--ignore-preflight-errors=Swap
......
[discovery] Trying to connect to API Server "192.168.61.11:6443"
[discovery] Created cluster-info discovery client, requesting info from "https://192.168.61.11:6443"
[discovery] Requesting info from "https://192.168.61.11:6443" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server "192.168.61.11:6443"
[discovery] Successfully established connection with API Server "192.168.61.11:6443"
[kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.11" ConfigMap in the kube-system namespace
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[preflight] Activating the kubelet service
[tlsbootstrap] Waiting for the kubelet to perform the TLS Bootstrap...
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "node2" as an annotation
This node has joined the cluster:
* Certificate signing request was sent to master and a response
was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the master to see this node join the cluster.
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node2加入集群很是顺利,下面在master节点上执行命令查看集群中的节点:
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kubectl get nodes
NAME STATUS ROLES AGE VERSION
node1 Ready master 26m v1.11.1
node2 Ready <none> 2m v1.11.1
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如何从集群中移除Node
如果需要从集群中移除node2这个Node执行下面的命令:
在master节点上执行:
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kubectl drain node2 --delete-local-data --force --ignore-daemonsets
kubectl delete node node2
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在node2上执行:
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kubeadm reset
ifconfig cni0 down
ip link delete cni0
ifconfig flannel.1 down
ip link delete flannel.1
rm -rf /var/lib/cni/
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3.Kubernetes常用组件部署
越来越多的公司和团队开始使用Helm这个Kubernetes的包管理器,我们也将使用Helm安装Kubernetes的常用组件。
3.1 Helm的安装
Helm由客户端命helm令行工具和服务端tiller组成,Helm的安装十分简单。
下载helm命令行工具到master节点node1的/usr/local/bin下,这里下载的2.9.1版本:
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wget https://storage.googleapis.com/kubernetes-helm/helm-v2.9.1-linux-amd64.tar.gz
tar -zxvf helm-v2.9.1-linux-amd64.tar.gz
cd linux-amd64/
cp helm /usr/local/bin/
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为了安装服务端tiller,还需要在这台机器上配置好kubectl工具和kubeconfig文件,确保kubectl工具可以在这台机器上访问apiserver且正常使用。
这里的node1节点以及配置好了kubectl。
因为Kubernetes APIServer开启了RBAC访问控制,所以需要创建tiller使用的service account: tiller并分配合适的角色给它。 详细内容可以查看helm文档中的Role-based Access Control。 这里简单起见直接分配cluster-admin这个集群内置的ClusterRole给它。创建rbac-config.yaml文件:
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apiVersion: v1
kind: ServiceAccount
metadata:
name: tiller
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: tiller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: tiller
namespace: kube-system
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kubectl create -f rbac-config.yaml
serviceaccount/tiller created
clusterrolebinding.rbac.authorization.k8s.io/tiller created
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接下来使用helm部署tiller:
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helm init --service-account tiller --skip-refresh
Creating /root/.helm
Creating /root/.helm/repository
Creating /root/.helm/repository/cache
Creating /root/.helm/repository/local
Creating /root/.helm/plugins
Creating /root/.helm/starters
Creating /root/.helm/cache/archive
Creating /root/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /root/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation
Happy Helming!
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tiller默认被部署在k8s集群中的kube-system这个namespace下:
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kubectl get pod -n kube-system -l app=helm
NAME READY STATUS RESTARTS AGE
tiller-deploy-759cb9df9-fdg58 1/1 Running 0 2m
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helm version
Client: &version.Version{SemVer:"v2.9.1", GitCommit:"20adb27c7c5868466912eebdf6664e7390ebe710", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.9.1", GitCommit:"20adb27c7c5868466912eebdf6664e7390ebe710", GitTreeState:"clean"}
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注意由于某些原因需要网络可以访问gcr.io和kubernetes-charts.storage.googleapis.com,如果无法访问可以通过helm init --service-account tiller --tiller-image <your-docker-registry>/tiller:2.9.1 --skip-refresh
使用私有镜像仓库中的tiller镜像
3.2 使用Helm部署Nginx Ingress
为了便于将集群中的服务暴露到集群外部,从集群外部访问,接下来使用Helm将Nginx Ingress部署到Kubernetes上。
ingress-nginx.yaml:
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controller:
service:
externalIPs:
- 192.168.61.11
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helm repo update
helm install stable/nginx-ingress \
-n nginx-ingress \
--namespace ingress-nginx \
-f ingress-nginx.yaml
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如果访问http://192.168.61.11返回default backend,则部署完成:
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curl http://192.168.61.11/
default backend - 404
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3.2 将TLS证书配置到Kubernetes中
当使用Ingress将HTTPS的服务暴露到集群外部时,需要HTTPS证书,这里将*.frognew.com的证书和秘钥配置到Kubernetes中。
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kubectl create secret tls frognew-com-tls-secret --cert=fullchain.pem --key=privkey.pem -n kube-system
secret/frognew-com-tls-secret created
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后边部署在kube-system命名空间中的dashboard要使用这个证书,因此这里同样在kube-system中创建证书的secret
3.3 使用Helm部署dashboard
kubernetes-dashboard.yaml:
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ingress:
enabled: true
hosts:
- k8s.frognew.com
annotations:
nginx.ingress.kubernetes.io/ssl-redirect: "true"
nginx.ingress.kubernetes.io/secure-backends: "true"
tls:
- secretName: frognew-com-tls-secret
hosts:
- k8s.frognew.com
rbac:
clusterAdminRole: true
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注意因为Service kubernetes-dashboard启用了https,所以是secure backend,在创建Ingress时需要用annotation指定nginx.ingress.kubernetes.io/secure-backends: "true"
。
(更新:ingress-nginx更新的版本中改用nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
代替nginx.ingress.kubernetes.io/secure-backends: "true"
)
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helm install stable/kubernetes-dashboard \
-n kubernetes-dashboard \
--namespace kube-system \
-f kubernetes-dashboard.yaml
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kubectl -n kube-system get secret | grep kubernetes-dashboard-token
kubernetes-dashboard-token-tjj25 kubernetes.io/service-account-token 3 37s
kubectl describe -n kube-system secret/kubernetes-dashboard-token-tjj25
Name: kubernetes-dashboard-token-tjj25
Namespace: kube-system
Labels: <none>
Annotations: kubernetes.io/service-account.name=kubernetes-dashboard
kubernetes.io/service-account.uid=d19029f0-9cac-11e8-8d94-080027db403a
Type: kubernetes.io/service-account-token
Data
====
namespace: 11 bytes
token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.w1HZrtBOhANdqSRLNs22z8dQWd5IOCpEl9VyWQ6DUwhHfgpAlgdhEjTqH8TT0f4ftu_eSPnnUXWbsqTNDobnlxet6zVvZv1K-YmIO-o87yn2PGIrcRYWkb-ADWD6xUWzb0xOxu2834BFVC6T5p5_cKlyo5dwerdXGEMoz9OW0kYvRpKnx7E61lQmmacEeizq7hlIk9edP-ot5tCuIO_gxpf3ZaEHnspulceIRO_ltjxb8SvqnMglLfq6Bt54RpkUOFD1EKkgWuhlXJ8c9wJt_biHdglJWpu57tvOasXtNWaIzTfBaTiJ3AJdMB_n0bQt5CKAUnKBhK09NP3R0Qtqog
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在dashboard的登录窗口使用上面的token登录。

3.4 使用Helm部署heapster
heapster已经DEPRECATED,官方推荐使用metrics-server(https://github.com/kubernetes-incubator/metrics-server)。
关于metrics-server
的部署可以查看使用kubeadm安装Kubernetes 1.12中的“使用Helm部署metrics-server”。
4.总结
本次安装涉及到的Docker镜像:
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# kubernetes
k8s.gcr.io/kube-apiserver-amd64:v1.11.1
k8s.gcr.io/kube-scheduler-amd64:v1.11.1
k8s.gcr.io/kube-controller-manager-amd64:v1.11.1
k8s.gcr.io/kube-proxy-amd64:v1.11.1
k8s.gcr.io/etcd-amd64:3.2.18
k8s.gcr.io/pause:3.1
# network and dns
quay.io/coreos/flannel:v0.10.0-amd64
k8s.gcr.io/coredns:1.1.3
# helm and tiller
gcr.io/kubernetes-helm/tiller:v2.9.1
# nginx ingress
quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.17.1
k8s.gcr.io/defaultbackend:1.4
# dashboard
k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
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- pause镜像从Kubernetes 1.10开始就已经升级为3.1了
- Kubernetes 1.11开始使用CoreDNS替换了Kubernetes插件kube-dns
参考