kubeadm: remove flaky unit tests for chroot

This unit test contains some hacks are causing the bazel-test
e2e job to flake very often. Instead of maintaining this
unit test remove it completely. It has little benefits
WRT testing app/util/chroot*.go.

cmd/kubeadm/app/util/BUILD

@@ -46,7 +46,6 @@ go_test(
     srcs = [
         "arguments_test.go",
         "cgroupdriver_test.go",
-        "chroot_test.go",
         "endpoint_test.go",
         "error_test.go",
         "marshal_test.go",

cmd/kubeadm/app/util/chroot_test.go

@@ -1,66 +0,0 @@
-// +build !windows
-
-/*
-Copyright 2018 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 util
-
-import (
-	"os"
-	"os/exec"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-// Can't just call Chroot() because it will affect other tests in the
-// same process.  Golang makes it hard to just call fork(), so instead
-// we exec ourselves again, and run the test in the new subprocess.
-
-func testChrootReal(t *testing.T) {
-	testfile := filepath.FromSlash("/" + filepath.Base(os.Args[0]))
-	dir := filepath.Dir(os.Args[0])
-	if dir == "." {
-		t.Skip("skipping: running test at root somehow")
-	}
-	if err := Chroot(dir); err != nil {
-		if strings.Contains(err.Error(), "operation not permitted") {
-			t.Skip("skipping: insufficient permissions to chroot")
-		}
-		t.Fatalf("chroot error: %v", err)
-	}
-
-	// All file access should now be relative to `dir`
-	if _, err := os.Stat(testfile); err != nil {
-		t.Errorf("Expected file %q to exist, but got %v", testfile, err)
-	}
-}
-
-func TestChroot(t *testing.T) {
-	if os.Getenv("GO_TEST_CHROOT_FOR_REALZ") == "1" {
-		testChrootReal(t)
-		return
-	}
-
-	cmd := exec.Command(os.Args[0], "-test.v", "-test.run=TestChroot")
-	cmd.Env = []string{"GO_TEST_CHROOT_FOR_REALZ=1"}
-
-	out, err := cmd.Output()
-	t.Logf("subprocess output:\n%s", out)
-	if err != nil {
-		t.Errorf("subprocess error: %v", err)
-	}
-}