Deploying using Keadm

Keadm is used to install the cloud and edge components of KubeEdge. It is not responsible for installing K8s and runtime, so check dependences section in this doc first.

Please refer kubernetes-compatibility to get Kubernetes compatibility and determine what version of Kubernetes would be installed.

Limitation

  • Currently support of keadm is available for Ubuntu and CentOS OS. RaspberryPi supports is in-progress.
  • Need super user rights (or root rights) to run.

Setup Cloud Side (KubeEdge Master Node)

By default ports 10000 and 10002 in your cloudcore needs to be accessible for your edge nodes.

Note: port 10002 only needed since 1.3 release.

keadm init will install cloudcore, generate the certs and install the CRDs. It also provides a flag by which a specific version can be set.

IMPORTANT NOTE:

  1. At least one of kubeconfig or master must be configured correctly, so that it can be used to verify the version and other info of the k8s cluster.
  2. Please make sure edge node can connect cloud node using local IP of cloud node, or you need to specify public IP of cloud node with --advertise-address flag.
  3. --advertise-address(only work since 1.3 release) is the address exposed by the cloud side (will be added to the SANs of the CloudCore certificate), the default value is the local IP.

Example:

# keadm init --advertise-address="THE-EXPOSED-IP"(only work since 1.3 release)

Output:

Kubernetes version verification passed, KubeEdge installation will start...
...
KubeEdge cloudcore is running, For logs visit:  /var/log/kubeedge/cloudcore.log

(Only Needed in Pre 1.3 Release) Manually copy certs.tgz from cloud host to edge host(s)

Note: Since release 1.3, feature EdgeNode auto TLS Bootstrapping has been added and there is no need to manually copy certificate.

Now users still need to copy the certs to the edge nodes. In the future, it will support the use of tokens for authentication.

On edge host:

mkdir -p /etc/kubeedge

On cloud host:

cd /etc/kubeedge/
scp -r certs.tgz username@edge_node_ip:/etc/kubeedge

On edge host untar the certs.tgz file

cd /etc/kubeedge
tar -xvzf certs.tgz

Setup Edge Side (KubeEdge Worker Node)

Get Token From Cloud Side

Run keadm gettoken in cloud side will return the token, which will be used when joining edge nodes.

# keadm gettoken
27a37ef16159f7d3be8fae95d588b79b3adaaf92727b72659eb89758c66ffda2.eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1OTAyMTYwNzd9.JBj8LLYWXwbbvHKffJBpPd5CyxqapRQYDIXtFZErgYE

Join Edge Node

keadm join will install edgecore and mqtt. It also provides a flag by which a specific version can be set.

Example:

# keadm join --cloudcore-ipport=192.168.20.50:10000 --token=27a37ef16159f7d3be8fae95d588b79b3adaaf92727b72659eb89758c66ffda2.eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1OTAyMTYwNzd9.JBj8LLYWXwbbvHKffJBpPd5CyxqapRQYDIXtFZErgYE

IMPORTANT NOTE:

  1. --cloudcore-ipport flag is a mandatory flag.
  2. If you want to apply certificate for edge node automatically, --token is needed.
  3. The kubeEdge version used in cloud and edge side should be same.

Output:

Host has mosquit+ already installed and running. Hence skipping the installation steps !!!
...
KubeEdge edgecore is running, For logs visit:  /var/log/kubeedge/edgecore.log

Enable kubectl logs Feature

Before metrics-server deployed, kubectl logs feature must be activated:

  1. Make sure you can find the kubernetes ca.crt and ca.key files. If you set up your kubernetes cluster by kubeadm , those files will be in /etc/kubernetes/pki/ dir.

    ls /etc/kubernetes/pki/
    
  2. Set CLOUDCOREIPS env. The environment variable is set to specify the IP address of cloudcore, or a VIP if you have a highly available cluster.

    export CLOUDCOREIPS="192.168.0.139"
    

    (Warning: the same terminal is essential to continue the work, or it is necessary to type this command again.) Checking the environment variable with the following command:

    echo $CLOUDCOREIPS
    
  3. Generate the certificates for CloudStream on cloud node, however, the generation file is not in the /etc/kubeedge/, we need to copy it from the repository which was git cloned from GitHub. Change user to root:

    sudo su
    

    Copy certificates generation file from original cloned repository:

    cp $GOPATH/src/github.com/kubeedge/kubeedge/build/tools/certgen.sh /etc/kubeedge/
    

    Change directory to the kubeedge directory:

    cd /etc/kubeedge/
    

    Generate certificates from certgen.sh

    /etc/kubeedge/certgen.sh stream
    
  4. It is needed to set iptables on the host. (This command should be executed on every apiserver deployed node.)(In this case, this the master node, and execute this command by root.) Run the following command on the host on which each apiserver runs:

    Note: You need to set the cloudcoreips variable first

    iptables -t nat -A OUTPUT -p tcp --dport 10350 -j DNAT --to $CLOUDCOREIPS:10003
    

    Port 10003 and 10350 are the default ports for the CloudStream and edgecore, use your own ports if you have changed them.

    If you are not sure if you have setting of iptables, and you want to clean all of them. (If you set up iptables wrongly, it will block you out of your kubectl logs feature) The following command can be used to clean up iptables:

    iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
    
  5. Modify both /etc/kubeedge/config/cloudcore.yaml and /etc/kubeedge/config/edgecore.yaml on cloudcore and edgecore. Set up cloudStream and edgeStream to enable: true. Change the server IP to the cloudcore IP (the same as $CLOUDCOREIPS).

    Open the YAML file in cloudcore:

    sudo nano /etc/kubeedge/config/cloudcore.yaml
    

    Modify the file in the following part (enable: true):

    cloudStream:
      enable: true
      streamPort: 10003
      tlsStreamCAFile: /etc/kubeedge/ca/streamCA.crt
      tlsStreamCertFile: /etc/kubeedge/certs/stream.crt
      tlsStreamPrivateKeyFile: /etc/kubeedge/certs/stream.key
      tlsTunnelCAFile: /etc/kubeedge/ca/rootCA.crt
      tlsTunnelCertFile: /etc/kubeedge/certs/server.crt
      tlsTunnelPrivateKeyFile: /etc/kubeedge/certs/server.key
      tunnelPort: 10004
    

    Open the YAML file in edgecore:

    sudo nano /etc/kubeedge/config/edgecore.yaml
    

    Modify the file in the following part (enable: true), (server: 192.168.0.193:10004):

    edgeStream:
      enable: true
      handshakeTimeout: 30
      readDeadline: 15
      server: 192.168.0.139:10004
      tlsTunnelCAFile: /etc/kubeedge/ca/rootCA.crt
      tlsTunnelCertFile: /etc/kubeedge/certs/server.crt
      tlsTunnelPrivateKeyFile: /etc/kubeedge/certs/server.key
      writeDeadline: 15
    
  6. Restart all the cloudcore and edgecore.

    sudo su
    

    cloudCore:

    pkill cloudcore
    nohup cloudcore > cloudcore.log 2>&1 &
    

    edgeCore:

    systemctl restart edgecore.service
    

    If you fail to restart edgecore, check if that is because of kube-proxy and kill it. kubeedge reject it by default, we use a succedaneum called edgemesh

    Note: the importance is to avoid kube-proxy being deployed on edgenode. There are two methods to solve it:

    1. Add the following settings by calling kubectl edit daemonsets.apps -n kube-system kube-proxy:
    affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: node-role.kubernetes.io/edge
                    operator: DoesNotExist
    
    1. If you still want to run kube-proxy, ask edgecore not to check the environment by adding the env variable in edgecore.service :

      sudo vi /etc/kubeedge/edgecore.service
      
      • Add the following line into the edgecore.service file:
      Environment="CHECK_EDGECORE_ENVIRONMENT=false"
      
      • The final file should look like this:
      Description=edgecore.service
      
      [Service]
      Type=simple
      ExecStart=/root/cmd/ke/edgecore --logtostderr=false --log-file=/root/cmd/ke/edgecore.log
      Environment="CHECK_EDGECORE_ENVIRONMENT=false"
      
      [Install]
      WantedBy=multi-user.target
      

Support Metrics-server in Cloud

  1. The realization of this function point reuses cloudstream and edgestream modules. So you also need to perform all steps of Enable kubectl logs Feature.

  2. Since the kubelet ports of edge nodes and cloud nodes are not the same, the current release version of metrics-server(0.3.x) does not support automatic port identification (It is the 0.4.0 feature), so you need to manually compile the image from master branch yourself now.

    Git clone latest metrics server repository:

    git clone https://github.com/kubernetes-sigs/metrics-server.git
    

    Go to the metrics server directory:

    cd metrics-server
    

    Make the docker image:

    make container
    

    Check if you have this docker image:

    docker images
    
|                  REPOSITORY                           |                    TAG                   |   IMAGE ID   |     CREATE     |  SIZE  |
|-------------------------------------------------------|------------------------------------------|--------------|----------------|--------|
| gcr.io/k8s-staging-metrics-serer/ metrics-serer-amd64 | 6d92704c5a68cd29a7a81bce68e6c2230c7a6912 | a24f71249d69 | 19 seconds ago | 57.2MB |
| metrics-server-kubeedge                               |                 latest                   | aef0fa7a834c | 28 seconds ago | 57.2MB |
Make sure you change the tag of image by using its IMAGE ID to be compactable with image name in yaml file.

```bash
docker tag a24f71249d69 metrics-server-kubeedge:latest
```
  1. Apply the deployment yaml. For specific deployment documents, you can refer to https://github.com/kubernetes-sigs/metrics-server/tree/master/manifests.

    Note: those iptables below must be applyed on the machine (to be exactly network namespace, so metrics-server needs to run in hostnetwork mode also) metric-server runs on.

    iptables -t nat -A OUTPUT -p tcp --dport 10350 -j DNAT --to $CLOUDCOREIPS:10003
    

    (To direct the request for metric-data from edgecore:10250 through tunnel between cloudcore and edgecore, the iptables is vitally important.)

    Before you deploy metrics-server, you have to make sure that you deploy it on the node which has apiserver deployed on. In this case, that is the master node. As a consequence, it is needed to make master node schedulable by the following command:

    kubectl taint nodes --all node-role.kubernetes.io/master-
    

    Then, in the deployment.yaml file, it must be specified that metrics-server is deployed on master node. (The hostname is chosen as the marked label.) In metrics-server-deployment.yaml

        spec:
          affinity:
            nodeAffinity:
              requiredDuringSchedulingIgnoredDuringExecution:
                nodeSelectorTerms:
                - matchExpressions:
                  #Specify which label in [kubectl get nodes --show-labels] you want to match
                  - key: kubernetes.io/hostname
                    operator: In
                    values:
                    #Specify the value in key
                    - charlie-latest
    

IMPORTANT NOTE:

  1. Metrics-server needs to use hostnetwork network mode.

  2. Use the image compiled by yourself and set imagePullPolicy to Never.

  3. Enable the feature of –kubelet-use-node-status-port for Metrics-server

    Those settings need to be written in deployment yaml (metrics-server-deployment.yaml) file like this:

          volumes:
          # mount in tmp so we can safely use from-scratch images and/or read-only containers
          - name: tmp-dir
            emptyDir: {}
          hostNetwork: true                          #Add this line to enable hostnetwork mode
          containers:
          - name: metrics-server
            image: metrics-server-kubeedge:latest    #Make sure that the REPOSITORY and TAG are correct
            # Modified args to include --kubelet-insecure-tls for Docker Desktop (don't use this flag with a real k8s cluster!!)
            imagePullPolicy: Never                   #Make sure that the deployment uses the image you built up
            args:
              - --cert-dir=/tmp
              - --secure-port=4443
              - --v=2
              - --kubelet-insecure-tls
              - --kubelet-preferred-address-types=InternalDNS,InternalIP,ExternalIP,Hostname
              - --kubelet-use-node-status-port       #Enable the feature of --kubelet-use-node-status-port for Metrics-server
            ports:
            - name: main-port
              containerPort: 4443
              protocol: TCP
    

Reset KubeEdge Master and Worker nodes

Master

keadm reset will stop cloudcore and delete KubeEdge related resources from Kubernetes master like kubeedge namespace. It doesn’t uninstall/remove any of the pre-requisites.

It provides a flag for users to specify kubeconfig path, the default path is /root/.kube/config.

Example:

 # keadm reset --kube-config=$HOME/.kube/config

Node

keadm reset will stop edgecore and it doesn’t uninstall/remove any of the pre-requisites.