Section Number and Name:
Describe the issue:
Our only documentation (other than API documentation) on replicasets is a link to the Kubernetes documentation. Given that the master web console (a vital and core component to the cluster) runs as part of a replicaset, we need official downstream documentation describing how to use it. Since we do not maintain the Kubernetes documentation we need a mirror or otherwise our own set of documentation now that the feature is fully supported.
I have started working on this and will put up a PR soon.
Tracking this in https://github.com/openshift/openshift-docs/pull/11410
Can you please check the PR https://github.com/openshift/openshift-docs/pull/11410 for changes.
I have only included informational bits as part of this PR. As Deployments is recommended rather than using ReplicaSets.
In the notation:
<1> Set-based selector to filter keys. This selects all resources with key equal to `tier` and value equal to `frontend`.
Does this mean to say, the replicaset will select any node with key of tier and value of frontend? What other resources could it select? Or am I misunderstanding this
Yes, you are right, those are the resources it will select.
This is from what I understood by reading the docs at https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#resources-that-support-set-based-requirements
If PR looks good, I can go ahead and merge it.
I think we should specify that the match labels can be used as a form of node selector, otherwise it looks good
I have included this in PR.
I'm a little confused by `Equality-based selector to specify node selection criteria` is that meaning "nodeSelector"?
IMO, the `.spec.selector` field is the ReplicaSet manages all the pods with labels that match the selector. And the matchLabels and matchExpressions are ANDed together.
And The `spec.template.metadata.labels` should be: tier: frontend.
Thanks zhou ying for reviewing this,
I have updated the PR to include following changes:
- Equality-based selector to specify resources with labels that match the
- Changed `spec.template.metadata.labels` to `tier: frontend`
Checked the PR ,LGTM, thanks.
Commit pushed to master at https://github.com/openshift/openshift-docs
Merge pull request #11410 from gaurav-nelson/bug1570159-fixes
BZ#1570159 - added replicasets
Changes are live at https://docs.openshift.com/container-platform/3.9/architecture/core_concepts/deployments.html#replica-set