OpenShift Hive – Deploy Single Node (All-in-One) OKD Cluster on AWS

The concept of a single-node or All-in-One OpenShift / Kubernetes cluster isn’t something new, years ago when I was working with OpenShift 3 and before that with native Kubernetes, we were using single-node clusters as ephemeral development environment, integrations testing for pull-request or platform releases. It was only annoying because this required complex Jenkins pipelines, provision the node first, then install prerequisites and run the openshift-ansible installer playbook. Not always reliable and not a great experience but it done the job.

This is possible as well with the new OpenShift/OKD 4 version and with the help from OpenShift Hive. The experience is more reliable and quicker than previously and I don’t need to worry about de-provisioning, I will let Hive delete the cluster after a few hours automatically.

It requires a few simple modifications in the install-config. You need to add the Availability Zone you want where the instance will be created. When doing this the VPC will only have two subnets, one public and one private subnet in eu-west-1. You can also install the single-node cluster into an existing VPC you just have to specify subnet ids. Change the compute worker node replicas zero and control-plane replicas to one. Make sure to have an instance size with enough CPU and memory for all OpenShift components because they need to fit onto the single node. The rest of the install-config is pretty much standard.

apiVersion: v1
- name: worker
      - eu-west-1a
        iops: 100
        size: 22
        type: gp2
      type: r4.xlarge
  replicas: 0
  name: master
      - eu-west-1a
        iops: 100
        size: 22
        type: gp2
      type: r5.2xlarge
  replicas: 1
  creationTimestamp: null
  name: okd-aio
  - cidr:
    hostPrefix: 23
  networkType: OpenShiftSDN
    region: eu-west-1
pullSecret: ""
sshKey: ""

Create a new install-config secret for the cluster.

kubectl create secret generic install-config-aio -n okd --from-file=install-config.yaml=./install-config-aio.yaml

We will be using OpenShift Hive for the cluster deployment because the provision is more simplified and Hive can also apply any configuration using SyncSets or SelectorSyncSets which is needed. Add the annotation “2h” and Hive will automatically delete the cluster after 4 hours.

kind: ClusterDeployment
  creationTimestamp: null
  annotations: "2h"
  name: okd-aio 
  namespace: okd
  clusterName: okd-aio
    servingCertificates: {}
  installed: false
        name: aws-creds
      region: eu-west-1
      name: install-config-aio
    name: pull-secret
    name: ssh-key
    availableUpdates: null
      force: false
      image: ""
      version: ""
    observedGeneration: 0
    versionHash: ""

Apply the cluster deployment to your clusters namespace.

kubectl apply -f  ./clusterdeployment-aio.yaml

This is slightly faster than provision 6 nodes cluster and will take around 30mins until your ephemeral test cluster is ready to use.

4 Replies to “OpenShift Hive – Deploy Single Node (All-in-One) OKD Cluster on AWS”

  1. Hi Bernd,
    Thanks for the great tutorial. It is indeed awesome what you accomplished with it.
    I am still having some problems though . After following your tutorial step by step, I am able to see the installer pod running. The logs show me that everything is being created as expected, but after while waiting the 30 minutes for the bootstrapping to end I can see the “authorization operator” not being able to be validated and as a consequence is being degraded.
    Somehow the ip-address/healthz endpoint cannot be reached.
    After 30 minutes the error message comes, although the cluster is built, it is not usable.
    Do you maybe have a tip for this behaviour?
    Thanking you in advanced for any recommendation


    1. Hi Jose,
      The operators can go into a degraded state but mostly recover from this automatically but the problem with this on a single node that the pod cannot be scheduled somewhere else in case of issue.
      Can you post some of the error messages?
      Did you use the instance size and OKD version from my example or did you change anything there?

  2. Well, I stepped upon this looking for an easy way to get a simple/inexpensive OKD playing instance on AWS (with a working clean remove option). However, as not being an OKD or Hive guru, I still wonder if you would recommend it for this use case.

    If I understood right, you need a running Hive (on kubernetes?) for using your recipe. This, of course, is a problem in my use case.

    1. Hi Anno,
      Sorry for not getting back earlier, you can use this install method as well when using the manual through the openshift-install binary.
      Re-use my install-config.yaml you see in the article. The only problem that single node OKD cluster are working until version 4.5.
      Everything above 4.5 doesn’t work anymore and the installer requires 3x masters nodes at least.

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