Kubernetes+iSulad Environment Deployment

Preparing Cluster Servers

Prepare at least 3 machines running openEuler 20.03 LTS or later versions. The following table lists information about the machines.

Preparing Images and Software Packages

The following table lists software packages and images used in the example. The versions are for reference only.

If you perform the deployment in without an Internet connection, download the software packages, dependencies, and images in advance.

• Download software packages: https://repo.openeuler.org/openEuler-22.03-LTS-SP1/
• Download images from Docker Hub: https://hub.docker.com

Modifying the hosts File

1. Change the host name of the machine, for example, lab1.

   hostnamectl set-hostname lab1
   sudo -i
   

2. Configure host name resolution by modifying the /etc/hosts file on each machine.

   vim /etc/hosts
   

3. Add the following content (IP address and host name) to the hosts file:

   197.xxx.xxx.xxx lab1
   197.xxx.xxx.xxx lab2
   197.xxx.xxx.xxx lab3
   

Preparing the Environment

1. Disable the firewall/

   systemctl stop firewalld
   systemctl disable firewalld
   

2. Disable SELinux.

   setenforce 0
   

3. Disable memory swapping.

   swapoff -a
   sed -ri 's/.*swap.*/#&/' /etc/fstab
   

4. Configure the network and enable forwarding.

   $ cat > /etc/sysctl.d/kubernetes.conf <<EOF
   net.bridge.bridge-nf-call-iptables = 1
   net.ipv4.ip_forward = 1
   net.bridge.bridge-nf-call-ip6tables = 1
   vm.swappiness=0
   EOF
   

5. Enable the rules.

   modprobe overlay
   modprobe br_netfilter
   sysctl -p /etc/sysctl.d/kubernetes.conf
   

6. Configure the startup script.

   vim /etc/init.d/k8s.sh
   

   • Add the following content to the k8s.sh script:

     #!/bin/sh
     modprobe br_netfilter
     sysctl -w net.bridge.bridge-nf-call-ip6tables = 1
     sysctl -w net.bridge.bridge-nf-call-iptables = 1
     

   • Change the permissions aon the script.

     chmod +x /etc/init.d/k8s.sh
     

7. Create the configuration file.

   $ vim br_netfilte.service
   
   [Unit]
   Description=To enable the core module br_netfilter when reboot
   After=default.target
   [Service]
   ExecStart=/etc/init.d/k8s.sh
   # The path can be customized.
   [Install]
   WantedBy=default.target
   

   • Start the service.

     systemctl daemon-reload
     systemctl enable br_netfilter.service
     

8. Configure sysctl.

   sed -i "s/net.ipv4.ip_forward=0/net.ipv4.ip_forward=1/g" /etc/sysctl.conf
   sed -i 12a\vm.swappiness=0 /etc/sysctl.conf
   

Installing kubeadm, kubectl, kubelet, and iSulad

1. Install the software packages using Yum.

yum install -y kubernetes-kubeadm
yum install -y kubernetes-client
yum install -y kubernetes-kubelet
yum install -y iSulad

1. Enable kubelet to start upon system startup.

systemctl enable kubelet

Modifying iSulad Configurations

1. Open the /etc/isulad/deamon.json file.

vi /etc/isulad/daemon.json

1. Modify the file as follows:

{
    "group": "isula",
    "default-runtime": "lcr",
    "graph": "/var/lib/isulad",
    "state": "/var/run/isulad",
    "engine": "lcr",
    "log-level": "ERROR",
    "pidfile": "/var/run/isulad.pid",
    "log-opts": {
        "log-file-mode": "0600",
        "log-path": "/var/lib/isulad",
        "max-file": "1",
        "max-size": "30KB"
    },
    "log-driver": "stdout",
    "container-log": {
        "driver": "json-file"
    },
    "hook-spec": "/etc/default/isulad/hooks/default.json",
    "start-timeout": "2m",
    "storage-driver": "overlay2",
    "storage-opts": [
        "overlay2.override_kernel_check=true"
    ],
    "registry-mirrors": [
                "docker.io"
    ],
    "insecure-registries": [
                 "k8s.gcr.io",
                 "quay.io",
                 "oci.inhuawei.com",
                 "rnd-dockerhub.huawei.com",
                 "registry.aliyuncs.com",
                 "<IP address of the local image repository>"
    ],
    "pod-sandbox-image": "k8s.gcr.io/pause:3.2",
    "native.umask": "normal",
    "network-plugin": "cni",
    "cni-bin-dir": "/opt/cni/bin",
    "cni-conf-dir": "/etc/cni/net.d",
    "image-layer-check": false,
    "use-decrypted-key": true,
    "insecure-skip-verify-enforce": false,
    "cri-runtimes": {
        "kata": "io.containerd.kata.v2"
    }
}

1. Restart the isulad service.

   systemctl restart isulad
   

Loading the isulad Images

1. Check the required system images.

   kubeadm config images list
   

Pay attention to the versions in the output, as shown in the figure.

1. Pull the images using the isula command.

   Note: The versions in the following commands are for reference only. Use the versions in the preceding output.

   isula pull k8simage/kube-apiserver:v1.20.15
   isula pull k8simage/kube-controller-manager:v1.20.15
   isula pull k8simage/kube-scheduler:v1.20.15
   isula pull k8simage/kube-proxy:v1.20.15
   isula pull k8smx/pause:3.2
   isula pull k8smx/coredns:1.7.0
   isula pull k8smx/etcd:3.4.13-0
   

2. Modify the tags of the pulled images.

   isula tag k8simage/kube-apiserver:v1.20.15 k8s.gcr.io/kube-apiserver:v1.20.15
   isula tag k8simage/kube-controller-manager:v1.20.15 k8s.gcr.io/kube-controller-manager:v1.20.15
   isula tag k8simage/kube-scheduler:v1.20.15 k8s.gcr.io/kube-scheduler:v1.20.15
   isula tag k8simage/kube-proxy:v1.20.15 k8s.gcr.io/kube-proxy:v1.20.15
   isula tag k8smx/pause:3.2 k8s.gcr.io/pause:3.2
   isula tag k8smx/coredns:1.7.0 k8s.gcr.io/coredns:1.7.0
   isula tag k8smx/etcd:3.4.13-0 k8s.gcr.io/etcd:3.4.13-0
   

3. Remove the old images.

   isula rmi k8simage/kube-apiserver:v1.20.15
   isula rmi k8simage/kube-controller-manager:v1.20.15
   isula rmi k8simage/kube-scheduler:v1.20.15
   isula rmi k8simage/kube-proxy:v1.20.15
   isula rmi k8smx/pause:3.2
   isula rmi k8smx/coredns:1.7.0
   isula rmi k8smx/etcd:3.4.13-0
   

4. View pulled images.

   isula images
   

Installing crictl

yum install -y cri-tools

Installing conntrack

yum install -y conntrack

Initializing the Master Node

Initialize the master node.

kubeadm init --kubernetes-version v1.20.2 --cri-socket=/var/run/isulad.sock --pod-network-cidr=<IP address range of the pods>

• --kubernetes-version indicates the current Kubernetes version.
• --cri-socket specifies the engine, that is, isulad.
• --pod-network-cidr specifies the IP address range of the pods.

Enter the following commands as prompted:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

After the initialization, copy the last two lines of the output and run the copied commands on the nodes to add them to the master cluster. The commands can also be generated using the following command:

kubeadm token create --print-join-command

Adding Nodes

Paste the kubeadm join command generated on Master, add --cri-socket=/var/run/isulad.sock before --discovery-token-ca-cert-hash, and then run the command.

kubeadm join <IP address> --token bgyis4.euwkjqb7jwuenwvs --cri-socket=/var/run/isulad.sock --discovery-token-ca-cert-hash sha256:3792f02e136042e2091b245ac71c1b9cdcb97990311f9300e91e1c339e1dfcf6

Installing Calico Network Plugins

1. Pull Calico images.

   Configure the Calico network plugins on the Master node and pull the required images on each node.

   isula pull calico/node:v3.14.2
   isula pull calico/cni:v3.14.2
   isula pull calico/kube-controllers:v3.14.2
   isula pull calico/pod2daemon-flexvol:v3.14.2
   

2. Download the configuration file on Master.

   wget https://docs.projectcalico.org/v3.14/manifests/calico.yaml
   

3. Modify calico.yaml.

   # vim calico.yaml
   
   # Modify the following parameters.
   
   - name: IP_AUTODERECTION_METHOD
   Value: ”can-reach=197.3.10.254”
   
   - name: CALICO_IPV4POOL_IPIP
   Value: ”CrossSubnet”
   

   

   • If the default CNI of the pod is Flannel, add the following content to flannel.yaml:

     --iface=enp4s0
     

     

4. Create a pod.

   ubectl apply -f calico.yaml
   

   • If you want to delete the configuration file, run the following command:

     kubectl delete -f calico.yaml
     

5. View pod information.

   kubectl get pod -A -o wide
   

Checking the Master Node Information

kubectl get nodes -o wide

To reset a node, run the following command:

kubeadm reset