Shulou(Shulou.com)06/02 Report--

kubernetes（K8S） google

Features:

1. Lightweight: consumes little resources

2. Open source

3. Auto Scaling

4. Load Balancer

Highly available cluster replica data is preferably>= 3 odd

Component Description:

Main components:

APISERVER: Unified entry point for all services

CrontrollerManager: Maintain expected number of copies

Scheduler: responsible for introducing tasks and selecting appropriate nodes to assign tasks

ETCD: Key-value pair database stores all important information of K8S cluster (persistent)

Kubelet: Interact directly with the container engine to implement container lifecycle management

Kube-proxy: responsible for writing rules to IPTABLES, IPVS to implement service mapping access

Other plug-ins:

COREDNS: You can create a domain name IP mapping for SVC in the cluster

DASHBOARD: Provides a B/S access architecture for K8S clusters

INGRESS CONTROLLER: The official can only achieve four-layer proxy, INGRESS can achieve seven-layer proxy

FEDERATION: Provides a unified management function for multiple K8S across cluster centers

PROMETHEUS: Provides monitoring capabilities for K8S clusters

ELK: Provides unified analysis access platform for K8S cluster logs

k8s installation deployment:

System initialization of each node: the environment here is

k8s-master01 172.20.120.187

k8s-node01 172.20.120.184

k8s-node02 172.20.120.183

harbor 172.20.120.182

1. Set hostname and hostname ip resolution

# hostnamectl set-hostname k8s-node01

# vi /etc/hosts

172.20.120.187 k8s-master01

172.20.120.184 k8s-node01

172.20.120.183 k8s-node02

172.20.120.182 hub.nice.com

2. Install dependency packages

# yum install epel-release -y

# yum install conntrack ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git -y

3. Set firewall to iptables and clear rules

# systemctl stop firewalld && systemctl disable firewalld

# yum -y install iptables-services && systemctl start iptables && systemctl enable iptables && iptables -F && service iptables save

Turn off virtual memory and selinux

# swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\ 1/g' /etc/fstab

# setenforce 0 && sed -i 's/^SELINUX=.*/ SELINUX=disabled/' /etc/selinux/config

5. Adjust kernel parameters

# vim /etc/sysctl.d/kubernetes.conf

Required parameters:

net.bridge.bridge-nf-call-iptables=1

net.bridge.bridge-nf-call-ip6tables=1

net.ipv6.conf.all.disable_ipv6=1

Optional optimization parameters:

net.ipv4.ip_forward=1

net.ipv4.tcp_tw_recycle=0

vm. swap =0 #Disables swap space, only allows it when the system is in oom

vm.overcommit_memory=1 #Do not check if physical memory is sufficient

vm.panic_on_oom=0 #Open oom

fs.inotify.max_user_instances=8192

fs.inotify.max_user_watches=1048576

fs.file-max=52706963

fs.nr_open=52706963

net.netfilter.nf_conntrack_max=2310720

6. Adjust the system time zone

# timedatectl set-timezone Asia/Shanghai

# timedatectl set-local-rtc 0

# systemctl restart rsyslog crond

7. Close services that are not needed by the system

# systemctl stop postfix && systemctl disable postfix

8. Set rsyd and systemd journald

# mkdir /var/log/journal #Persist the directory where logs are saved

# mkdir /etc/systemd/journald.conf.d

# cat > /etc/systemd/journald.conf.d/99-prophet.conf kubeadm-config.yaml

# vim kubeadm-config.yaml

localAPIEndpoint:

advertiseAddress: 172.20.120.187 #modified to master IP address

kubernetesVersion: v1.15.1 #modified to correct version information

networking:

dnsDomain: cluster.local

podSubnet: 10.244.0.0/16 #Add default address for pod subnet provided by flannnel network plugin

serviceSubnet: 10.96.0.0/12

--- #Change default scheduling mode to ipvs mode

apiVersion: kubeproxy.config.k8s.io/v1alpha1

kind: KubeProxyConfiguration

featureGates:

SupportIPVSProxyMode: true

mode: ipvs

# kubeadm init --config=kubeadm-config.yaml --experimental-upload-certs |tee kubeadm-initlog #kubeadm initializes and logs information

# mkdir -p $HOME/.kube

# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

# chown $(id -u):$(id -g) $HOME/.kube/config

# kubectl get node #Get node status, status is noready because there is no flat network;

Deploying networks:

# mkdir -pv install-k8s/{core,plugin}

# mv kubeadm-initlog kubeadm-config.yaml install-k8s/core #kubeadm-initlog kubeadm-config.yaml needs to be preserved

# mkdir install-k8s/plugin/flannel

# cd install-k8s/plugin/flannel

# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

# kubectl create -f kube-flannel.yml

Verification:

# kubectl get pod -n kube-system #View pod status with kube-system namespace

# kubectl get node #Here the status is ready

# ifconfig |grep -A6 flannel #flannel network info

Add additional nodes to the master node, execute on the node that needs to be added: (command obtained in log at kubeadm initialization)

# kubeadm join 172.20.120.187:6443 --token abcdef.0123456789abcdef \

--discovery-token-ca-cert-hash sha256:d968d2936e8d3af4e2765805fa041621c90447217281d761cdb17ca5e5eb9a40

Verification:

# kubectl get pod -n kube-system -o wide #support-w for surveillance

# kubectl get nodes #status should be ready, support-w for monitoring

Enterprise docker private repository: harbour, installed separately on harbour node here

https://github.com/goharbor/harbor/blob/master/docs/installation_guide.md

Requirements:

Docker engine version 17.06.0-ce+ or higher https://docs.docker.com/install/linux/docker-ce/centos/

Docker Compose version 1.18.0 or higher https://docs.docker.com/compose/install/

Openssllatest is preferred

Install docker:

# yum install -y yum-utils device-mapper-persistent-data lvm2

# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# yum install -y docker-ce

# systemctl start docker && systemctl enable docker

##Configure deamon

# cat > /etc/docker/daemon.json

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