Chapter 2 kubectl deployment doesn't work on a real cluster
Closed this issue · 4 comments
In chapter 2 the command you show to deploy the myhello application gives a different output than you show when I run it on the master of a 3 node cluster:
$ kubectl run demo --image=dwschulze/myhello --port=9999 --labels app=demo
pod/demo created
The output you show is:
deployment.apps "demo" created
When I try to do the port forwarding it fails because I have no deployments.
Do I need a deployment.yaml to deploy this onto a real cluster, or is there a different kubectl command I use?
This is the command that is needed on a cluster:
$ sudo kubectl create deployment demo --image=demo
Maybe on a single node too?
@dwschulze thanks for opening an issue!
Are you by chance running version 1.18 of Kubernetes?
I think the issue you are experiencing could be due to a change in the 1.18 release. The latest release of Kubernetes back when the book was published was 1.10 or 1.11 so this could be a case where Kubernetes has changed something and our example no longer works with newer versions.
After searching docs between 1.17 and 1.18 it looks like kubectl run no longer creates a Deployment:
1.17 docs (https://v1-17.docs.kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#run)
Creates a deployment or job to manage the created container(s).
1.18 docs (https://v1-18.docs.kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#run)
Create and run a particular image in a pod.
Let us know if that lines up with your current version and we'll get an update to the Known Issues section in the demo repo with an updated example.
I'm running 1.18.2. Should probably go into the errata too.
PR merged with updated Known Issue in the README.
(Not sure why GitHub labeled the PR as "Closed" instead of "Merged").
Also submitted errata to O'Reilly.
Thank you @dwschulze for catching this!