Merge pull request #55448 from yguo0905/spec-change-for-new-kernel

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fix GKE system spec for OS images with kernel version 4.10+

Two changes are required for validating images with kernel version 4.10+.

1. Update the spec in gke.yaml to allow 4.10+ kernel.
2. Update the GKE environment docker validation to allow `CONFIG_DEVPTS_MULTIPLE_INSTANCES` to be missing in >= 4.8 kernel because this option has been removed in 4.8.

**Release note**:

```
None
```

/assign @dchen1107

test/e2e_node/BUILD

@@ -137,6 +137,7 @@ go_test(
         "//test/e2e_node/services:go_default_library",
         "//test/e2e_node/system:go_default_library",
         "//test/utils/image:go_default_library",
+        "//vendor/github.com/blang/semver:go_default_library",
         "//vendor/github.com/coreos/go-systemd/util:go_default_library",
         "//vendor/github.com/davecgh/go-spew/spew:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",

test/e2e_node/gke_environment_test.go

@@ -28,6 +28,7 @@ import (
 
 	"k8s.io/kubernetes/test/e2e/framework"
 
+	"github.com/blang/semver"
 	. "github.com/onsi/ginkgo"
 )
 
@@ -122,6 +123,18 @@ func checkDockerConfig() error {
 		}
 		missing = map[string]bool{}
 	)
+
+	// Whitelists CONFIG_DEVPTS_MULTIPLE_INSTANCES (meaning allowing it to be
+	// absent) if the kernel version is >= 4.8, because this option has been
+	// removed from the 4.8 kernel.
+	kernelVersion, err := getKernelVersion()
+	if err != nil {
+		return err
+	}
+	if kernelVersion.GTE(semver.MustParse("4.8.0")) {
+		whitelist["CONFIG_DEVPTS_MULTIPLE_INSTANCES"] = true
+	}
+
 	for _, bin := range bins {
 		if _, err := os.Stat(bin); os.IsNotExist(err) {
 			continue
@@ -400,3 +413,18 @@ func getCmdToProcessMap() (map[string][]process, error) {
 	}
 	return result, nil
 }
+
+// getKernelVersion returns the kernel version in the semantic version format.
+func getKernelVersion() (*semver.Version, error) {
+	output, err := runCommand("uname", "-r")
+	if err != nil {
+		return nil, err
+	}
+	// An example 'output' could be "4.13.0-1001-gke".
+	v := strings.TrimSpace(strings.Split(output, "-")[0])
+	kernelVersion, err := semver.Make(v)
+	if err != nil {
+		return nil, fmt.Errorf("failed to convert %q to semantic version: %s", v, err)
+	}
+	return &kernelVersion, nil
+}

test/e2e_node/system/specs/gke.yaml

@@ -5,7 +5,9 @@ os: Linux
 kernelSpec:
   versions:
   # GKE requires kernel version 4.4+.
-  - 4\.[4-9].*
+  - '4\.[4-9].*'
+  - '4\.[1-9][0-9].*'
+  - '[5-9].*'
 
   # Required kernel configurations -- the configuration must be set to "y" or
   # "m".