Change:
<ins> /* Copyright 2021 The Kubernetes Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package architecture import ( "time" "github.com/onsi/ginkgo" "k8s.io/kubernetes/test/e2e/framework" e2enode "k8s.io/kubernetes/test/e2e/framework/node" ) var _ = SIGDescribe("Conformance Tests", func() { f := framework.NewDefaultFramework("conformance-tests") /* Release: v1.23 Testname: Conformance tests minimum number of nodes. Description: Conformance tests requires at least two untainted nodes where pods can be scheduled. */ framework.ConformanceIt("should have at least two untainted nodes", func() { ginkgo.By("Getting node addresses") framework.ExpectNoError(framework.WaitForAllNodesSchedulable(f.ClientSet, 10*time.Minute)) nodeList, err := e2enode.GetReadySchedulableNodes(f.ClientSet) framework.ExpectNoError(err) if len(nodeList.Items) < 2 { framework.Failf("Conformance requires at least two nodes") } }) }) </ins>

Discussion:
I can create a cluster with one node and pass conformance, ~there are some tests that require at least 2 nodes to run~ ~~ ~This is because the tests Skip if they are not able to run~ ~~ ~As consequence, the list of tests for conformance depends on the number of nodes, a single cluster node (that is not a cluster by definition of cluster :)) will run less tests than a multi cluster node and still be Conformant~ EDIT I have to correct myself, it seems that the conformance tests doesn't skip, the problem is: there are no conformance tests that exercise anything that requires more than one node, hence, single node cluster can pass conformance. I expect a cluster (a group of similar things or people positioned or occurring closely together) and a "distributed system" to not be able to be single-node. In addition, lots of most important Kubernetes features can not be exercised on one node, lowering the quality bar. local- pass conformance Related discussion <details</details<details</details<details</details<details</details<details</details<details</details
/assign Maybe this has changed, but last time I've checked the minimum for conformance was 1 control-plane and 2 workers, if that didn't change I will submit a PR to enforce it in the suite Regarding sig-network, with one node you can not verify the networking model, where pod to pod in different nodes should be able to communicate without NAT, that is a strong requirement ... I have to review closely what tests do we have in Conformance
/area conformance /sig network
that seems pretty intentional... changing the definition of conformance to require multiple nodes probably deserves more feedback than an issue/PR
I'm not changing the definition, just asserting it
if we are testing features like replicaset, daemonset, services, ..., in one node only we are missing a lot of testing on those features ... a podman/docker single node can be a kubernetes conformance cluster ... do I need a scheduler or network for anything, I'm just deploying always in the same node?
No I don't think so. Where are your results and configuration? You need two schedulable nodes to pass the conformance suite. That's not correct, we test rolling pod behavior with replicasets. This test requires multiple nodes. There is at least one.

That job is not passing conformance, from the configuration: (see: ) Conformance requires not setting --, you must run all tests without skipping. We don't, at the very least replicaset is being tested multi-node, just not in this job that is not running the full conformance suite. When conformance results are submitted they are now validated to ensure that all tests were run.