Question on Lab 3.2 Step 10

trancewu0317

Hi, all,

I was trying the lab on AWS cloud. I successfully started a master and a node, and the node has successfully joined the cluster. However, when I start the deployment, there is no available nginx in the deployment.

=========== output ============

ubuntu@ip-10-0-0-69:~$ kubectl get deployments

NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE

nginx     1         1         1            0           23m

=========== output ============

The event is as follows, which shows the pod sandbox fails.

=========== output ============

26m         26m          1         nginx-8586cf59-ppkph.1526b633df971998   Pod                      Normal    Scheduled                 default-scheduler          Successfully assigned nginx-8586cf59-ppkph to ip-10-0-0-5

26m         26m          1         nginx-8586cf59-ppkph.1526b633f408be87   Pod                      Normal    SuccessfulMountVolume     kubelet, ip-10-0-0-5       MountVolume.SetUp succeeded for volume "default-token-m995p" 

26m         26m          12        nginx-8586cf59-ppkph.1526b6340363db54   Pod                      Warning   FailedCreatePodSandBox    kubelet, ip-10-0-0-5       Failed create pod sandbox.

26m         26m          12        nginx-8586cf59-ppkph.1526b6343c62c19d   Pod                      Normal    SandboxChanged            kubelet, ip-10-0-0-5       Pod sandbox changed, it will be killed and re-created.

12m         12m          1         nginx-8586cf59-ppkph.1526b6f60dca5608   Pod                      Normal    SuccessfulMountVolume     kubelet, ip-10-0-0-5       MountVolume.SetUp succeeded for volume "default-token-m995p" 

7m          12m          298       nginx-8586cf59-ppkph.1526b6f636c470e4   Pod                      Warning   FailedCreatePodSandBox    kubelet, ip-10-0-0-5       Failed create pod sandbox.

2m          12m          584       nginx-8586cf59-ppkph.1526b6f6548f8d19   Pod                      Normal    SandboxChanged            kubelet, ip-10-0-0-5       Pod sandbox changed, it will be killed and re-created.

26m         26m          1         nginx-8586cf59.1526b633ded64e2d         ReplicaSet               Normal    SuccessfulCreate          replicaset-controller      Created pod: nginx-8586cf59-ppkph

26m         26m          1         nginx.1526b633dd5d3b91                  Deployment               Normal    ScalingReplicaSet         deployment-controller      Scaled up replica set nginx-8586cf59 to 1

=========== output ============

Does anyone have any idea about what went wrong in this?

Also, does anyone have any idea about the steps to turn down the EC2 instance when I finish practicing, and then turn on the instances to resume practicing? Thanks.

chrispokorni

Hi, 

In case you missed this earlier, I attempted the Labs from Chapter 3 on 2 EC2 instances on AWS and I did not run into any issues. In addition to possible join issue, or taints, as mentioned by @serewicz, I also researched the issue you have described, and I found several discussions on similar error/warning messages, and most of them suggest it may be networking related. It may have to do with the pod network used (Flannel, Calico) and/or the networking/firewall rules (security group, VPC, network ACL) configured for the EC2 instances. 

I setup my 2 EC2's as Ubuntu VMs on t2.micro, with public IPs, inside a default security group where I opened all inbound TCP traffic (clearly not best practice, but for the purpose of these exercises it works). 

Here is a list of ports used by Kubernetes which need to be open on each node:

https://kubernetes.io/docs/setup/independent/install-kubeadm/#check-required-ports

Aside from providing the outputs requested by @serewicz, can you also provide some details about your EC2 setup in AWS? It may also help in identifying the source of your issues.

Good luck!

-Chris