Merge pull request #5622 from neolit123/1.21-add-note-about-minimum-kubelet-version

sig-testing/e2e-tests.md: add notes about MinimumKubeletVersion

contributors/devel/sig-testing/e2e-tests.md

@@ -98,6 +98,9 @@ kubetest --test --test_args="--ginkgo.focus=\[Feature:Performance\]" --provider=
 # Conversely, exclude tests that match the regex "Pods.*env"
 kubetest --test --test_args="--ginkgo.skip=Pods.*env"
 
+# Exclude tests tha require a certain minimum version of the kubelet
+kubetest --test --test_args="--ginkgo.skip=\[MinimumKubeletVersion:1.20\]"
+
 # Run tests in parallel, skip any that must be run serially
 GINKGO_PARALLEL=y kubetest --test --test_args="--ginkgo.skip=\[Serial\]"
 
@@ -441,6 +444,12 @@ breaking changes, it does *not* block PR merges, and thus should run in
 some separate test suites owned by the feature owner(s)
 (see [Continuous Integration](#continuous-integration) below).
 
+  - `[MinimumKubeletVersion:.+]`: This label must be set on tests that require
+a minimum version of the kubelet. Invocations of the test suite can then decide
+to `skip` the same tests if kubelets in the cluster do not satisfy the requirement.
+For example, `[MinimumKubeletVersion:(1.20|1.21)]` would `skip` tests with minimum
+kubelet versions `1.20` and `1.21`.
+
   - `[Conformance]`: Designate that this test is included in the Conformance
 test suite for [Conformance Testing](../sig-architecture/conformance-tests.md). This test must
 meet a number of [requirements](../sig-architecture/conformance-tests.md#conformance-test-requirements)