07. Networking - Deploy Network Solution

07. Networking

01. Explore Environment
02. CNI weave
03. Deploy Network Solution
04. Networking Weave
05. Service Networking
06. CoreDNS in Kubernetes
07. CKA – Ingress Networking – 1
08. CKA – Ingress Networking – 2

 

 

 

01. In this practice test we will install weave-net POD networking solution to the cluster.

Let us first inspect the setup.

 

We have deployed an application called app in the default namespace. What is the state of the pod?

 

ask : NotRunning

 

root@controlplane:~# k describe pod/app
Name:         app
Namespace:    default
Priority:     0
Node:         controlplane/10.13.20.9
Start Time:   Thu, 27 Jan 2022 07:38:06 +0000
Labels:       run=app
Annotations:  <none>
Status:       Pending
IP:           
IPs:          <none>
Containers:
  app:
    Container ID:  
    Image:         busybox
    Image ID:      
    Port:          <none>
    Host Port:     <none>
    Args:
      sleep
      1000
    State:          Waiting
      Reason:       ContainerCreating
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-nfvgq (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             False 
  ContainersReady   False 
  PodScheduled      True 
Volumes:
  default-token-nfvgq:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-nfvgq
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason                  Age               From               Message
  ----     ------                  ----              ----               -------
  Normal   Scheduled               85s               default-scheduler  Successfully assigned default/app to controlplane
  Warning  FailedCreatePodSandBox  79s               kubelet            Failed to create pod sandbox: rpc error: code = Unknown desc = [failed to set up sandbox container "b60102f4a600d9c5f012f570a5cee420a8438fd2d950d7bc25531b7858901d3c" network for pod "app": networkPlugin cni failed to set up pod "app_default" network: unable to allocate IP address: Post "http://127.0.0.1:6784/ip/b60102f4a600d9c5f012f570a5cee420a8438fd2d950d7bc25531b7858901d3c": dial tcp 127.0.0.1:6784: connect: connection refused, failed to clean up sandbox container "b60102f4a600d9c5f012f570a5cee420a8438fd2d950d7bc25531b7858901d3c" network for pod "app": networkPlugin cni failed to teardown pod "app_default" network: Delete "http://127.0.0.1:6784/ip/b60102f4a600d9c5f012f570a5cee420a8438fd2d950d7bc25531b7858901d3c": dial tcp 127.0.0.1:6784: connect: connection refused]
  Normal   SandboxChanged          1s (x7 over 78s)  kubelet            Pod sandbox changed, it will be killed and re-created.

 

02. Inspect why the POD is not running.

1) Wrong image

2) No Network Configured

3) Faulty start command

4) Node failed

 

 

03. Deploy weave-net networking solution to the cluster.

Replace the default IP address and subnet of weave-net to the 10.50.0.0/16.

Please check the official weave installation and configuration guide which is available at the top right panel.

 

클러스터에 weave-net 네트워킹 솔루션을 배포합니다. weave-net의 기본 IP 주소와 서브넷을 10.50.0.0/16으로 바꿉니다. 오른쪽 상단 패널에 있는 공식 weave 설치 및 구성 가이드를 확인하십시오.

 

• Deploy weave
• Wait for the app to run
  
  

kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"


root@controlplane:~# kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
serviceaccount/weave-net created
clusterrole.rbac.authorization.k8s.io/weave-net created
clusterrolebinding.rbac.authorization.k8s.io/weave-net created
role.rbac.authorization.k8s.io/weave-net created
rolebinding.rbac.authorization.k8s.io/weave-net created
daemonset.apps/weave-net created

https://www.weave.works/docs/net/latest/kubernetes/kube-addon/#-installation

Integrating Kubernetes via the Addon

$ echo "s3cr3tp4ssw0rd" > /var/lib/weave/weave-passwd
$ kubectl create secret -n kube-system generic weave-passwd --from-file=/var/lib/weave/weave-passwd
$ kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')&password-secret=weave-passwd"

https://www.weave.works/docs/net/latest/kubernetes/kube-addon/#-changing-configuration-options

Integrating Kubernetes via the Addon

root@controlplane:~# kubectl get pods -n kube-system
NAME                                   READY   STATUS    RESTARTS   AGE
coredns-74ff55c5b-kn7tk                1/1     Running   0          39m
coredns-74ff55c5b-zh6gt                1/1     Running   0          39m
etcd-controlplane                      1/1     Running   0          40m
kube-apiserver-controlplane            1/1     Running   0          40m
kube-controller-manager-controlplane   1/1     Running   0          40m
kube-proxy-926nj                       1/1     Running   0          39m
kube-scheduler-controlplane            1/1     Running   0          40m
weave-net-4n7gs                        2/2     Running   0          37s