2021, still can't Kubernetes - Moment For Technology

1. What is Kubernetes

Kubernetes is seen as a platform for deploying images
It can be used to schedule deployment images on multiple machines
In Kubernetes, you can use clusters to organize servers. One will exist in the clusterMasterNode, which is the control node of the Kubernetes cluster and is responsible for scheduling resources for other servers in the cluster. Other nodes are called nodes

2. Basic installation

Both Master and Node nodes need to be installed

2.1 Install required Components

Vim is a file editor for Linux
Wget can be used as a file download
Ntpdate can be used to synchronize time zones

yum install vim wget ntpdate -y
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2.2 Disabling the Firewall

Kubernetes will create firewall rules, first closedfirewalld

systemctl stop firewalld & systemctl disable firewalld
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2.3 Disabling a Swap Partition

Swap is a Linux Swap partition. When system resources are insufficient, Swap will be enabled, which is unnecessary
Instead of using Swap partitions, the newly created service should be automatically scheduled to other nodes in the cluster

# temporarily shut down Swapoff-aCopy the code

2.4 close the Selinux

Selinux is turned off to support container access to the host file system

# Temporarily disable Selinux SetenForce0/etc/sysconfig/selinux: disable selinux =disabledCopy the code

2.5 Unify our system time and time zone

usentpdateTo unify our system time and time zone, and align the server time with Ali Cloud server

# unified time zones for the Shanghai time zone ln - SNF/usr/share/zoneinfo/Asia/Shanghai/etc/localtime bash - c"echo 'Asia/Shanghai' > /etc/timezone"# Use ali server for time update ntpdate ntp1.aliyun.comCopy the code

2.6 installation Docker

In Kubernetes components, services can be Docker image deployment, so you need to install Docker
Device-mapper-persistent-data: Storage driver, many advanced volume management techniques on Linux
LVM: logical volume manager used to create logical disk partitions

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


sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum install docker-ce -y
systemctl start docker
systemctl enable docker

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://fwvjnv59.mirror.aliyuncs.com"]
}
EOF

sudo systemctl daemon-reload
sudo systemctl restart docker.service
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2.7 Installing Kubernetes Components

2.7.1 Switching over Ali Cloud Source

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
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2.7.2 Installing Kubernetes Components

Kubelet is the core component of Kubernetes. It runs on all nodes of the cluster and is responsible for creating the startup service container
Kubectl is the command line tool of Kubernetes. Can be used to manage, delete, create resources
Kubeadm is a tool used to initialize the cluster and add child nodes

Yum install -y kubelet kubeadm kubectl # yum install -y kubelet kubeadm kubectl #Copy the code

2.8 set up the bridge – nf – call – iptables

Configure kernel parameters to pass the bridged IPV4 browsing to the IPtables chain
Open the bridge – nf – call – iptables

echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables
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3. Master

The Master node is the scheduling and primary node in the cluster

3.1 Changing the host name to master

hostnamectl set-hostname  master
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3.2 configure hosts

ip addr
vim /etc/hosts

172.31178.169.  master  master
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3.3 Configuring Kubernetes Initialization Files

init-defaultsOutput a default initialization configuration file

kubeadm config print init-defaults > init-kubeadm.conf
vim init-kubeadm.conf
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Replace Kubernetes mirror warehouse for Ali cloud mirror warehouse, accelerate component pull
Replace the IP address with the host IP address
Set the POD network toflannelNetwork segment
To enable clusters to communicate with each other, you need to configure sub-networks, which will be used in the flannel network
- 10.96.0.0/12 is the network required by Kubernetes internal network Pods
- 10.244.0.0/16 is the network required by Kubernetes internal services

- imageRepository: k8s.gcr. IO replace k8s imageRepository
+ imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
- localAPIEndpointc, advertiseAddress is the master IP address. Port is not changed by default
localAPIEndpoint:
+ advertiseAddress: 172.31.178.169 # Indicates the IP address of the masterDnsDomain: cluster.local serviceSubnet: 10.96.0.0/12+ podSubnet: 10.244.0.0/16 # Add this
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3.3 Pull other components

Kubeadm can be used to pull our default component image
Kube-apiserver provides interface services that allow external networks to access the cluster
Kube-controller-manager internal control instruction tool
Kube-scheduler Internal task scheduler
Kube-proxy Reverse proxy, load balancer, and traffic forwarding
Pause process management tool
Etcd maintains data consistency within the cluster
Coredns cluster Intranet communication

// View missing components
kubeadm config images list --config init-kubeadm.conf
// Pull the missing component
kubeadm config images pull --config init-kubeadm.conf
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3.4 Initializing Kubernetes

kubeadm init --config init-kubeadm.conf
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Kubeadm Join can quickly add nodes to the Master cluster
Initialization command for the Master node
Copy the default Kubernetes authentication file into the.kube folder to use the configuration file by default

Your Kubernetes control-plane 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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.31178.169.:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:8aac19f4dbe68f1e15ba3d80e141acdc912e353f9757ad69187e8fb9780bc975 
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3.5 installation Flannel

flannelIt is used to create a virtual network so that services on different nodes have globally unique IP addresses and can access and connect to each other.
Cluster Intranet communication protocol The Flannel protocol is used

#wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
wget http://img.golderbrother.cn/kube-flannel.yml
docker pull quay.io/coreos/flannel:v013.. 0-rc2
kubectl apply -f kube-flannel.yml
net-conf.json: |
    {
      "Network": "10.244.0.0/16"."Backend": {
        "Type": "vxlan"}}Copy the code

3.6 Viewing the Startup Status

kubectl get nodes

NAME     STATUS   ROLES                  AGE     VERSION
master   Ready    control-plane,master   9m34s   v120.4.
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3.7 Node Node configuration

The Node Node is responsible for running the service container and receiving scheduling.
Perform basic installation first

hostnamectl set-hostname node1
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3.8 Copying the Configuration File of the Master Node

Copy the configuration file of master node k8S to node1

scp $HOME/.kube/config root@172.31178.170.: ~ /Copy the code

Archive the configuration file on node1

mkdir -p $HOME/.kube
sudo mv $HOME/config $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
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3.9 Adding a Master Node

Add nodes to the master cluster

kubeadm join 172.1681.164.:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:b4a059eeffa2e52f2eea7a5d592be10c994c7715c17bda57bbc3757d4f13903d
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If the command is lost, you can use kubeadm token create to generate a new command on the master machine
```
kubeadm token create --print-join-command
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```

3.10. Installation of Flannel

scp ~/ kube - flannel. Yml [email protected]: ~ /
kubectl apply -f kube-flannel.yml
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4. Check the status

kubectl get nodes
NAME     STATUS   ROLES                  AGE    VERSION
master   Ready    control-plane,master   24m    v120.4.
node1    Ready    <none>                 101s   v120.4.
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5. Deploy nginx directly

kubectl create deployment nginx --image=nginx
[root@master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed
kubectl get pod,svc
NAME                            READY   STATUS    RESTARTS   AGE
pod/nginx-6799fc88d8-bt5n6      1/1     Running   0          5m32s

curl 127.0. 01.:32636
// Rapidly expand the number of copies to three
[root@master ~]# kubectl scale deployment nginx --replicas=3
deployment.apps/nginx scaled
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6. Deploy mysql through YAML

6.1 Configuration File

apiVersion: v1
kind: ReplicationController                           
metadata:
  name: mysql                                          
spec:
  replicas: 1           # Expected number of Pod copies
  selector:
    app: mysql          Pods that match the target have this tag
  template:             Create a Pod copy (instance) from this template
    metadata:
      labels:
        app: mysql     #Pod copy has a tag corresponding to RC Selector
    spec:
      containers:      # The defining part of the container inside Pod
      - name: mysql            The name of the container
        image: mysql    The Docker image of the container
        ports: 
        - containerPort: 3306       The container application listens to the port number
        env:                        Inject environment variables into the container
        - name: MYSQL_ROOT_PASSWORD 
          value: "123456"
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6.2 create a POD

kubectl create -f mysql-rc.yaml
replicationcontroller/mysql created

kubectl get pods
NAME          READY   STATUS    RESTARTS   AGE
mysql         1/1     Running      0      5m56s
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6.3 Viewing Status

kubectl describe pod mysql
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2021, still can’t Kubernetes

1. What is Kubernetes

2. Basic installation

2.1 Install required Components

2.2 Disabling the Firewall

2.3 Disabling a Swap Partition

2.4 close the Selinux

2.5 Unify our system time and time zone

2.6 installation Docker

2.7 Installing Kubernetes Components

2.7.1 Switching over Ali Cloud Source

2.7.2 Installing Kubernetes Components

2.8 set up the bridge – nf – call – iptables

3. Master

3.1 Changing the host name to master

3.2 configure hosts

3.3 Configuring Kubernetes Initialization Files

3.3 Pull other components

3.4 Initializing Kubernetes

3.5 installation Flannel

3.6 Viewing the Startup Status

3.7 Node Node configuration

3.8 Copying the Configuration File of the Master Node

3.9 Adding a Master Node

3.10. Installation of Flannel

4. Check the status

5. Deploy nginx directly

6. Deploy mysql through YAML

6.1 Configuration File

6.2 create a POD

6.3 Viewing Status

2021, still can’t Kubernetes

1. What is Kubernetes

2. Basic installation

2.1 Install required Components

2.2 Disabling the Firewall

2.3 Disabling a Swap Partition

2.4 close the Selinux

2.5 Unify our system time and time zone

2.6 installation Docker

2.7 Installing Kubernetes Components

2.7.1 Switching over Ali Cloud Source

2.7.2 Installing Kubernetes Components

2.8 set up the bridge – nf – call – iptables

3. Master

3.1 Changing the host name to master

3.2 configure hosts

3.3 Configuring Kubernetes Initialization Files

3.3 Pull other components

3.4 Initializing Kubernetes

3.5 installation Flannel

3.6 Viewing the Startup Status

3.7 Node Node configuration

3.8 Copying the Configuration File of the Master Node

3.9 Adding a Master Node

3.10. Installation of Flannel

4. Check the status

5. Deploy nginx directly

6. Deploy mysql through YAML

6.1 Configuration File

6.2 create a POD

6.3 Viewing Status

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