最近着手使用k8s搭建内部容器云平台，在搭建kubernetes集群时遇到一些问题，网上有不少搭建文档可以参考，但是满足以下网络互通才能算k8s集群ready
node <-> pod #主机和pod之前IP可互相ping通
pod <-> pod #同/跨主机Pod之间可互相ping通
pod -> svc cluster ip #pod可以访问Service 的cluster ip
node -> svc cluster ip #node可以访问Service 的cluster ip
kubernetes 集群结构图
image.png
以下是版本和机器信息:
- kubernetes 1.7.2
- docker 1.12
- calico 2.3.0
- centos 7 x86_64 三个节点
10.12.0.18 -> k8s master
10.12.0.19 -> k8s node1
10.12.0.22 -> k8s node2, etcd node
节点初始化
- 更新CentOS-Base.repo为阿里云yum源
mv -f /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bk;
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
设置bridge
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-arptables = 1
EOF
sudo sysctl --system
- disable selinux （请不要用setenforce 0）
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
- 关闭防火墙
sudo systemctl disable firewalld.service
sudo systemctl stop firewalld.service
- 关闭iptables
sudo yum install -y iptables-services;iptables -F; #可略过
sudo systemctl disable iptables.service
sudo systemctl stop iptables.service
- 清理之前的K8S环境(若有)
systemctl daemon-reload
systemctl stop kubelet;systemctl stop kube-proxy
rm -rf /etc/systemd/system/kube-proxy.service /etc/systemd/system/kubelet.service
systemctl daemon-reload
docker ps -aq |xargs docker rm -f
rm -rf /etc/kubernetes/ssl/* /var/lib/kube*
systemctl stop etcd
rm -rf /etc/etcd/ssl /var/lib/etcd /etc/systemd/system/etcd.service
systemctl daemon-reload
- 安装相关软件
sudo yum install -y vim wget curl screen git etcd ebtables flannel
sudo yum install -y socat net-tools.x86_64 iperf bridge-utils.x86_64
- 安装docker (目前默认安装是1.12)
sudo yum install -y yum-utils device-mapper-persistent-data lvm2
sudo yum install -y libdevmapper* docker
- 安装kubernetes
##设置kubernetes.repo为阿里云源，适合国内
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
EOF
##设置kubernetes.repo为阿里云源，适合能连通google的网络
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://yum.kubernetes.io/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
## 安装k8s 1.7.2 (kubernetes-cni会作为依赖一并安装,在此没有做版本指定)
export K8SVERSION=1.7.2
sudo yum install -y "kubectl-${K8SVERSION}-0.x86_64" "kubelet-${K8SVERSION}-0.x86_64" "kubeadm-${K8SVERSION}-0.x86_64"
- 升级kernel到最新（4.12.5 ,可选)
uname -sr
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
yum --enablerepo=elrepo-kernel install -y kernel-ml
awk -F\' '$1=="menuentry " {print i++ " @ " $2}' /etc/grub2.cfg
grub2-set-default 0
- 重启机器 （这一步是需要的）
reboot
重启机器后执行如下步骤
- 配置docker daemon并启动docker
cat <<EOF >/etc/sysconfig/docker
OPTIONS="-H unix:///var/run/docker.sock -H tcp://127.0.0.1:2375 --storage-driver=overlay --exec-opt native.cgroupdriver=cgroupfs --graph=/localdisk/docker/graph --insecure-registry=gcr.io --insecure-registry=quay.io --insecure-registry=registry.cn-hangzhou.aliyuncs.com --registry-mirror=http://138f94c6.m.daocloud.io"
EOF
systemctl start docker
systemctl status docker -l
- 拉取k8s 1.7.2 需要的镜像
quay.io/calico/node:v1.3.0
quay.io/calico/cni:v1.9.1
quay.io/calico/kube-policy-controller:v0.6.0
gcr.io/google_containers/pause-amd64:3.0
gcr.io/google_containers/kube-proxy-amd64:v1.7.2
gcr.io/google_containers/kube-apiserver-amd64:v1.7.2
gcr.io/google_containers/kube-controller-manager-amd64:v1.7.2
gcr.io/google_containers/kube-scheduler-amd64:v1.7.2
gcr.io/google_containers/etcd-amd64:3.0.17
gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64:1.14.4
gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.4
gcr.io/google_containers/k8s-dns-sidecar-amd64:1.14.4
- 在非k8s master节点 10.12.0.22 上启动ETCD (图省事，也可搭建成ETCD集群)
screen etcd -name="EtcdServer" -initial-advertise-peer-urls=http://10.12.0.22:2380 -listen-peer-urls=http://0.0.0.0:2380 -listen-client-urls=http://10.12.0.22:2379 -advertise-client-urls http://10.12.0.22:2379 -data-dir /var/lib/etcd/default.etcd
- 在每个节点上check是否可通达ETCD， 必须可通才行, 不通需要看下防火墙是不是没有关闭
etcdctl --endpoint=http://10.12.0.22:2379 member list
etcdctl --endpoint=http://10.12.0.22:2379 cluster-health
- 在k8s master节点上使用kubeadm启动，
pod-ip网段设定为10.68.0.0/16, cluster-ip网段为默认10.96.0.0/16
如下命令在master节点上执行
cat << EOF >kubeadm_config.yaml
apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
api:
advertiseAddress: 10.12.0.18
bindPort: 6443
etcd:
endpoints:
- http://10.12.0.22:2379
networking:
dnsDomain: cluster.local
serviceSubnet: 10.96.0.0/16
podSubnet: 10.68.0.0/16
kubernetesVersion: v1.7.2
#token: <string>
#tokenTTL: 0
EOF
##
kubeadm init --config kubeadm_config.yaml
- 执行kubeadm init命令后稍等几十秒，master上api-server, scheduler, controller-manager容器都启动起来，以下命令来check下master
如下命令在master节点上执行
rm -rf $HOME/.kube
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get cs -o wide --show-labels
kubectl get nodes -o wide --show-labels
- 节点加入, 需要kubeadm init命令输出的token, 如下命令在node节点上执行
systemctl start docker
systemctl start kubelet
kubeadm join --token *{6}.*{16} 10.12.0.18:6443 --skip-preflight-checks
- 在master节点上观察节点加入情况， 因为还没有创建网络，所以，所有master和node节点都是NotReady状态， kube-dns也是pending状态
kubectl get nodes -o wide
watch kubectl get all --all-namespaces -o wide
- 对calico.yaml做了修改
删除ETCD创建部分，使用外部ETCD
修改CALICO_IPV4POOL_CIDR为10.68.0.0/16
calico.yaml如下
# Calico Version v2.3.0
# http://docs.projectcalico.org/v2.3/releases#v2.3.0
# This manifest includes the following component versions:
# calico/node:v1.3.0
# calico/cni:v1.9.1
# calico/kube-policy-controller:v0.6.0
# This ConfigMap is used to configure a self-hosted Calico installation.
kind: ConfigMap
apiVersion: v1
metadata:
name: calico-config
namespace: kube-system
data:
# The location of your etcd cluster. This uses the Service clusterIP defined below.
etcd_endpoints: "http://10.12.0.22:2379"
# Configure the Calico backend to use.
calico_backend: "bird"
# The CNI network configuration to install on each node.
cni_network_config: |-
{
"name": "k8s-pod-network",
"cniVersion": "0.1.0",
"type": "calico",
"etcd_endpoints": "__ETCD_ENDPOINTS__",
"log_level": "info",
"ipam": {
"type": "calico-ipam"
},
"policy": {
"type": "k8s",
"k8s_api_root": "https://__KUBERNETES_SERVICE_HOST__:__KUBERNETES_SERVICE_PORT__",
"k8s_auth_token": "__SERVICEACCOUNT_TOKEN__"
},
"kubernetes": {
"kubeconfig": "/etc/cni/net.d/__KUBECONFIG_FILENAME__"
}
}
---
# This manifest installs the calico/node container, as well
# as the Calico CNI plugins and network config on
# each master and worker node in a Kubernetes cluster.
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
name: calico-node
namespace: kube-system
labels:
k8s-app: calico-node
spec:
selector:
matchLabels:
k8s-app: calico-node
template:
metadata:
labels:
k8s-app: calico-node
annotations:
# Mark this pod as a critical add-on; when enabled, the critical add-on scheduler
# reserves resources for critical add-on pods so that they can be rescheduled after
# a failure. This annotation works in tandem with the toleration below.
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
hostNetwork: true
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
# Allow this pod to be rescheduled while the node is in "critical add-ons only" mode.
# This, along with the annotation above marks this pod as a critical add-on.
- key: CriticalAddonsOnly
operator: Exists
serviceAccountName: calico-cni-plugin
containers:
# Runs calico/node container on each Kubernetes node. This
# container programs network policy and routes on each
# host.
- name: calico-node
image: quay.io/calico/node:v1.3.0
env:
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# Enable BGP. Disable to enforce policy only.
- name: CALICO_NETWORKING_BACKEND
valueFrom:
configMapKeyRef:
name: calico-config
key: calico_backend
# Disable file logging so `kubectl logs` works.
- name: CALICO_DISABLE_FILE_LOGGING
value: "true"
# Set Felix endpoint to host default action to ACCEPT.
- name: FELIX_DEFAULTENDPOINTTOHOSTACTION
value: "ACCEPT"
# Configure the IP Pool from which Pod IPs will be chosen.
- name: CALICO_IPV4POOL_CIDR
value: "10.68.0.0/16"
- name: CALICO_IPV4POOL_IPIP
value: "always"
# Disable IPv6 on Kubernetes.
- name: FELIX_IPV6SUPPORT
value: "false"
# Set Felix logging to "info"
- name: FELIX_LOGSEVERITYSCREEN
value: "info"
# Auto-detect the BGP IP address.
- name: IP
value: ""
securityContext:
privileged: true
resources:
requests:
cpu: 250m
volumeMounts:
- mountPath: /lib/modules
name: lib-modules
readOnly: true
- mountPath: /var/run/calico
name: var-run-calico
readOnly: false
# This container installs the Calico CNI binaries
# and CNI network config file on each node.
- name: install-cni
image: quay.io/calico/cni:v1.9.1
command: ["/install-cni.sh"]
env:
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# The CNI network config to install on each node.
- name: CNI_NETWORK_CONFIG
valueFrom:
configMapKeyRef:
name: calico-config
key: cni_network_config
volumeMounts:
- mountPath: /host/opt/cni/bin
name: cni-bin-dir
- mountPath: /host/etc/cni/net.d
name: cni-net-dir
volumes:
# Used by calico/node.
- name: lib-modules
hostPath:
path: /lib/modules
- name: var-run-calico
hostPath:
path: /var/run/calico
# Used to install CNI.
- name: cni-bin-dir
hostPath:
path: /opt/cni/bin
- name: cni-net-dir
hostPath:
path: /etc/cni/net.d
---
# This manifest deploys the Calico policy controller on Kubernetes.
# See https://github.com/projectcalico/k8s-policy
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: calico-policy-controller
namespace: kube-system
labels:
k8s-app: calico-policy
spec:
# The policy controller can only have a single active instance.
replicas: 1
strategy:
type: Recreate
template:
metadata:
name: calico-policy-controller
namespace: kube-system
labels:
k8s-app: calico-policy-controller
annotations:
# Mark this pod as a critical add-on; when enabled, the critical add-on scheduler
# reserves resources for critical add-on pods so that they can be rescheduled after
# a failure. This annotation works in tandem with the toleration below.
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
# The policy controller must run in the host network namespace so that
# it isn't governed by policy that would prevent it from working.
hostNetwork: true
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
# Allow this pod to be rescheduled while the node is in "critical add-ons only" mode.
# This, along with the annotation above marks this pod as a critical add-on.
- key: CriticalAddonsOnly
operator: Exists
serviceAccountName: calico-policy-controller
containers:
- name: calico-policy-controller
image: quay.io/calico/kube-policy-controller:v0.6.0
env:
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# The location of the Kubernetes API. Use the default Kubernetes
# service for API access.
- name: K8S_API
value: "https://kubernetes.default:443"
# Since we're running in the host namespace and might not have KubeDNS
# access, configure the container's /etc/hosts to resolve
# kubernetes.default to the correct service clusterIP.
- name: CONFIGURE_ETC_HOSTS
value: "true"
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: calico-cni-plugin
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: calico-cni-plugin
subjects:
- kind: ServiceAccount
name: calico-cni-plugin
namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: calico-cni-plugin
namespace: kube-system
rules:
- apiGroups: [""]
resources:
- pods
- nodes
verbs:
- get
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: calico-cni-plugin
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: calico-policy-controller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: calico-policy-controller
subjects:
- kind: ServiceAccount
name: calico-policy-controller
namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: calico-policy-controller
namespace: kube-system
rules:
- apiGroups:
- ""
- extensions
resources:
- pods
- namespaces
- networkpolicies
verbs:
- watch
- list
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: calico-policy-controller
namespace: kube-system
- 创建calico跨主机网络, 在master节点上执行如下命令
kubectl apply -f calico.yaml
- 注意观察每个节点上会有名为calico-node-****的pod起来， calico-policy-controller和kube-dns也会起来， 这些pod都在kube-system名字空间里
>kubectl get all --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system po/calico-node-2gqf2 2/2 Running 0 19h
kube-system po/calico-node-fg8gh 2/2 Running 0 19h
kube-system po/calico-node-ksmrn 2/2 Running 0 19h
kube-system po/calico-policy-controller-1727037546-zp4lp 1/1 Running 0 19h
kube-system po/etcd-izuf6fb3vrfqnwbct6ivgwz 1/1 Running 0 19h
kube-system po/kube-apiserver-izuf6fb3vrfqnwbct6ivgwz 1/1 Running 0 19h
kube-system po/kube-controller-manager-izuf6fb3vrfqnwbct6ivgwz 1/1 Running 0 19h
kube-system po/kube-dns-2425271678-3t4g6 3/3 Running 0 19h
kube-system po/kube-proxy-6fg1l 1/1 Running 0 19h
kube-system po/kube-proxy-fdbt2 1/1 Running 0 19h
kube-system po/kube-proxy-lgf3z 1/1 Running 0 19h
kube-system po/kube-scheduler-izuf6fb3vrfqnwbct6ivgwz 1/1 Running 0 19h
NAMESPACE NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default svc/kubernetes 10.96.0.1 <none> 443/TCP 19h
kube-system svc/kube-dns 10.96.0.10 <none> 53/UDP,53/TCP 19h
NAMESPACE NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
kube-system deploy/calico-policy-controller 1 1 1 1 19h
kube-system deploy/kube-dns 1 1 1 1 19h
NAMESPACE NAME DESIRED CURRENT READY AGE
kube-system rs/calico-policy-controller-1727037546 1 1 1 19h
kube-system rs/kube-dns-2425271678 1 1 1 19h
- 部署dash-board
wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/kubernetes-dashboard.yaml
kubectl create -f kubernetes-dashboard.yaml
- 部署heapster
wget https://github.com/kubernetes/heapster/archive/v1.4.0.tar.gz
tar -zxvf v1.4.0.tar.gz
cd heapster-1.4.0/deploy/kube-config/influxdb
kubectl create -f ./
其他命令
- 强制删除某个pod
kubectl delete pod <podname> --namespace=<namspacer> --grace-period=0 --force
- 重置某个node节点
kubeadm reset
systemctl stop kubelet;
docker ps -aq | xargs docker rm -fv
find /var/lib/kubelet | xargs -n 1 findmnt -n -t tmpfs -o TARGET -T | uniq | xargs -r umount -v;
rm -rf /var/lib/kubelet /etc/kubernetes/ /var/lib/etcd
systemctl start kubelet;
- 访问dashboard (在master节点上执行)
kubectl proxy --address=0.0.0.0 --port=8001 --accept-hosts='^.*'
or
kubectl proxy --port=8011 --address=192.168.61.100 --accept-hosts='^192\.168\.61\.*'
access to http://0.0.0.0:8001/ui
- Access to API with authentication token
APISERVER=$(kubectl config view | grep server | cut -f 2- -d ":" | tr -d " ")
TOKEN=$(kubectl describe secret $(kubectl get secrets | grep default | cut -f1 -d ' ') | grep -E '^token' | cut -f2 -d':' | tr -d '\t')
curl $APISERVER/api --header "Authorization: Bearer $TOKEN" --insecure
- 让master节点参与调度，默认master是不参与到任务调度中的
kubectl taint nodes --all node-role.kubernetes.io/master-
or
kubectl taint nodes --all dedicated-
- kubernetes master 消除隔离之前 Annotations
Name: izuf6fb3vrfqnwbct6ivgwz
Role:
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=izuf6fb3vrfqnwbct6ivgwz
node-role.kubernetes.io/master=
Annotations: node.alpha.kubernetes.io/ttl=0
volumes.kubernetes.io/controller-managed-attach-detach=true
- kubernetes master 消除隔离之后 Annotations
Name: izuf6fb3vrfqnwbct6ivgwz
Role:
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=izuf6fb3vrfqnwbct6ivgwz
node-role.kubernetes.io/master=
Annotations: node.alpha.kubernetes.io/ttl=0
volumes.kubernetes.io/controller-managed-attach-detach=true
Taints: <none>
另外我也遇到比较坑爹的事，同样的步骤在阿里云、ucloud上搭建k8s集群都没问题，但是在Azure上calico网络 跨主机pod间不通，到现在还不知道问题出在哪里。。。
后续分享命令行方式搭建k8s集群，以及k8s高可用的实施
附一些参考链接
kubeadm安装kubernetes 1.6
http://blog.frognew.com/2017/04/kubeadm-install-kubernetes-1.6.htmlkubeadm搭建kubernetes集群 1.4
https://mritd.me/2016/10/29/set-up-kubernetes-cluster-by-kubeadm/阿里云快速部署K8s-VPC环境
https://yq.aliyun.com/articles/66474使用Kubeadm安装Kubernetes1.5版本
http://www.openskill.cn/article/511http://tonybai.com/2016/12/30/install-kubernetes-on-ubuntu-with-kubeadm/
