Merge pull request #36334 from luxas/add_preflight

Automatic merge from submit-queue

Add the system verification test to the kubeadm preflight checks

And refactor the system verification test to accept to write to a specific writer in order to customize the output

This PR is targeting v1.5, PTAL
cc @Random-Liu @dchen1107 @kubernetes/sig-cluster-lifecycle

cmd/kubeadm/app/preflight/BUILD

@@ -19,6 +19,7 @@ go_library(
         "//pkg/api/validation:go_default_library",
         "//pkg/util/initsystem:go_default_library",
         "//pkg/util/node:go_default_library",
+        "//test/e2e_node/system:go_default_library",
     ],
 )
 

cmd/kubeadm/app/preflight/checks.go

@@ -17,6 +17,7 @@ limitations under the License.
 package preflight
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
 	"io"
@@ -29,6 +30,7 @@ import (
 	"k8s.io/kubernetes/pkg/api/validation"
 	"k8s.io/kubernetes/pkg/util/initsystem"
 	"k8s.io/kubernetes/pkg/util/node"
+	"k8s.io/kubernetes/test/e2e_node/system"
 )
 
 type PreFlightError struct {
@@ -213,9 +215,26 @@ func (hst HttpProxyCheck) Check() (warnings, errors []error) {
 	return nil, nil
 }
 
+type SystemVerificationCheck struct{}
+
+func (sysver SystemVerificationCheck) Check() (warnings, errors []error) {
+	// Create a buffered writer and choose a quite large value (1M) and suppose the output from the system verification test won't exceed the limit
+	bufw := bufio.NewWriterSize(os.Stdout, 1*1024*1024)
+
+	// Run the system verification check, but write to out buffered writer instead of stdout
+	err := system.Validate(system.DefaultSysSpec, &system.StreamReporter{WriteStream: bufw})
+	if err != nil {
+		// Only print the output from the system verification check if the check failed
+		fmt.Println("System verification failed. Printing the output from the verification...")
+		bufw.Flush()
+		return nil, []error{err}
+	}
+	return nil, nil
+}
+
 func RunInitMasterChecks(cfg *kubeadmapi.MasterConfiguration) error {
-	// TODO: Some of these ports should come from kubeadm config eventually:
 	checks := []PreFlightCheck{
+		SystemVerificationCheck{},
 		IsRootCheck{root: true},
 		HostnameCheck{},
 		ServiceCheck{Service: "kubelet"},
@@ -249,8 +268,8 @@ func RunInitMasterChecks(cfg *kubeadmapi.MasterConfiguration) error {
 }
 
 func RunJoinNodeChecks(cfg *kubeadmapi.NodeConfiguration) error {
-	// TODO: Some of these ports should come from kubeadm config eventually:
 	checks := []PreFlightCheck{
+		SystemVerificationCheck{},
 		IsRootCheck{root: true},
 		HostnameCheck{},
 		ServiceCheck{Service: "docker"},

test/e2e_node/e2e_node_suite_test.go

@@ -92,7 +92,7 @@ func TestE2eNode(t *testing.T) {
 				glog.Exitf("chroot %q failed: %v", rootfs, err)
 			}
 		}
-		if err := system.Validate(); err != nil {
+		if err := system.ValidateDefault(); err != nil {
 			glog.Exitf("system validation failed: %v", err)
 		}
 		return

test/e2e_node/system/BUILD

@@ -17,8 +17,8 @@ go_library(
         "docker_validator.go",
         "kernel_validator.go",
         "os_validator.go",
+        "report.go",
         "types.go",
-        "util.go",
         "validators.go",
     ],
     tags = ["automanaged"],

test/e2e_node/system/cgroup_validator.go

@@ -25,7 +25,9 @@ import (
 
 var _ Validator = &CgroupsValidator{}
 
-type CgroupsValidator struct{}
+type CgroupsValidator struct {
+	Reporter Reporter
+}
 
 func (c *CgroupsValidator) Name() string {
 	return "cgroups"
@@ -55,9 +57,9 @@ func (c *CgroupsValidator) validateCgroupSubsystems(cgroupSpec, subsystems []str
 		}
 		item := cgroupsConfigPrefix + strings.ToUpper(cgroup)
 		if found {
-			report(item, "enabled", good)
+			c.Reporter.Report(item, "enabled", good)
 		} else {
-			report(item, "missing", bad)
+			c.Reporter.Report(item, "missing", bad)
 			missing = append(missing, cgroup)
 		}
 	}

test/e2e_node/system/cgroup_validator_test.go

@@ -23,7 +23,9 @@ import (
 )
 
 func TestValidateCgroupSubsystem(t *testing.T) {
-	v := &CgroupsValidator{}
+	v := &CgroupsValidator{
+		Reporter: DefaultReporter,
+	}
 	cgroupSpec := []string{"system1", "system2"}
 	for desc, test := range map[string]struct {
 		cgroupSpec []string

test/e2e_node/system/docker_validator.go

@@ -28,7 +28,9 @@ import (
 var _ Validator = &DockerValidator{}
 
 // DockerValidator validates docker configuration.
-type DockerValidator struct{}
+type DockerValidator struct {
+	Reporter Reporter
+}
 
 func (d *DockerValidator) Name() string {
 	return "docker"
@@ -63,22 +65,22 @@ func (d *DockerValidator) validateDockerInfo(spec *DockerSpec, info types.Info)
 	for _, v := range spec.Version {
 		r := regexp.MustCompile(v)
 		if r.MatchString(info.ServerVersion) {
-			report(dockerConfigPrefix+"VERSION", info.ServerVersion, good)
+			d.Reporter.Report(dockerConfigPrefix+"VERSION", info.ServerVersion, good)
 			matched = true
 		}
 	}
 	if !matched {
-		report(dockerConfigPrefix+"VERSION", info.ServerVersion, bad)
+		d.Reporter.Report(dockerConfigPrefix+"VERSION", info.ServerVersion, bad)
 		return fmt.Errorf("unsupported docker version: %s", info.ServerVersion)
 	}
 	// Validate graph driver.
 	item := dockerConfigPrefix + "GRAPH_DRIVER"
-	for _, d := range spec.GraphDriver {
-		if info.Driver == d {
-			report(item, info.Driver, good)
+	for _, gd := range spec.GraphDriver {
+		if info.Driver == gd {
+			d.Reporter.Report(item, info.Driver, good)
 			return nil
 		}
 	}
-	report(item, info.Driver, bad)
+	d.Reporter.Report(item, info.Driver, bad)
 	return fmt.Errorf("unsupported graph driver: %s", info.Driver)
 }

test/e2e_node/system/docker_validator_test.go

@@ -24,7 +24,9 @@ import (
 )
 
 func TestValidateDockerInfo(t *testing.T) {
-	v := &DockerValidator{}
+	v := &DockerValidator{
+		Reporter: DefaultReporter,
+	}
 	spec := &DockerSpec{
 		Version:     []string{`1\.(9|\d{2,})\..*`},
 		GraphDriver: []string{"driver_1", "driver_2"},

test/e2e_node/system/kernel_validator.go

@@ -39,6 +39,7 @@ var _ Validator = &KernelValidator{}
 // and kernel configuration.
 type KernelValidator struct {
 	kernelRelease string
+	Reporter      Reporter
 }
 
 func (k *KernelValidator) Name() string {
@@ -60,11 +61,11 @@ const (
 )
 
 func (k *KernelValidator) Validate(spec SysSpec) error {
-	out, err := exec.Command("uname", "-r").CombinedOutput()
+	release, err := exec.Command("uname", "-r").CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("failed to get kernel release: %v", err)
 	}
-	k.kernelRelease = strings.TrimSpace(string(out))
+	k.kernelRelease = strings.TrimSpace(string(release))
 	var errs []error
 	errs = append(errs, k.validateKernelVersion(spec.KernelSpec))
 	errs = append(errs, k.validateKernelConfig(spec.KernelSpec))
@@ -78,11 +79,11 @@ func (k *KernelValidator) validateKernelVersion(kSpec KernelSpec) error {
 	for _, versionRegexp := range versionRegexps {
 		r := regexp.MustCompile(versionRegexp)
 		if r.MatchString(k.kernelRelease) {
-			report("KERNEL_VERSION", k.kernelRelease, good)
+			k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, good)
 			return nil
 		}
 	}
-	report("KERNEL_VERSION", k.kernelRelease, bad)
+	k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, bad)
 	return fmt.Errorf("unsupported kernel release: %s", k.kernelRelease)
 }
 
@@ -101,7 +102,7 @@ func (k *KernelValidator) validateCachedKernelConfig(allConfig map[string]kConfi
 	badConfigs := []string{}
 	// reportAndRecord is a helper function to record bad config when
 	// report.
-	reportAndRecord := func(name, msg, desc string, result resultType) {
+	reportAndRecord := func(name, msg, desc string, result ValidationResultType) {
 		if result == bad {
 			badConfigs = append(badConfigs, name)
 		}
@@ -109,7 +110,7 @@ func (k *KernelValidator) validateCachedKernelConfig(allConfig map[string]kConfi
 		if result != good && desc != "" {
 			msg = msg + " - " + desc
 		}
-		report(name, msg, result)
+		k.Reporter.Report(name, msg, result)
 	}
 	const (
 		required = iota
@@ -117,7 +118,7 @@ func (k *KernelValidator) validateCachedKernelConfig(allConfig map[string]kConfi
 		forbidden
 	)
 	validateOpt := func(config KernelConfig, expect int) {
-		var found, missing resultType
+		var found, missing ValidationResultType
 		switch expect {
 		case required:
 			found, missing = good, bad

test/e2e_node/system/kernel_validator_test.go

@@ -24,7 +24,9 @@ import (
 )
 
 func TestValidateKernelVersion(t *testing.T) {
-	v := &KernelValidator{}
+	v := &KernelValidator{
+		Reporter: DefaultReporter,
+	}
 	// Currently, testRegex is align with DefaultSysSpec.KernelVersion, but in the future
 	// they may be different.
 	// This is fine, because the test mainly tests the kernel version validation logic,
@@ -69,7 +71,9 @@ func TestValidateKernelVersion(t *testing.T) {
 }
 
 func TestValidateCachedKernelConfig(t *testing.T) {
-	v := &KernelValidator{}
+	v := &KernelValidator{
+		Reporter: DefaultReporter,
+	}
 	testKernelSpec := KernelSpec{
 		Required: []KernelConfig{{Name: "REQUIRED_1"}, {Name: "REQUIRED_2", Aliases: []string{"ALIASE_REQUIRED_2"}}},
 		Optional: []KernelConfig{{Name: "OPTIONAL_1"}, {Name: "OPTIONAL_2"}},
@@ -184,7 +188,9 @@ CONFIG_3=n`
 		"CONFIG_2": asModule,
 		"CONFIG_3": leftOut,
 	}
-	v := &KernelValidator{}
+	v := &KernelValidator{
+		Reporter: DefaultReporter,
+	}
 	got, err := v.parseKernelConfig(bytes.NewReader([]byte(config)))
 	assert.Nil(t, err, "Expect error not to occur when parse kernel configuration %q", config)
 	assert.Equal(t, expected, got)

test/e2e_node/system/os_validator.go

@@ -24,25 +24,27 @@ import (
 
 var _ Validator = &OSValidator{}
 
-type OSValidator struct{}
+type OSValidator struct {
+	Reporter Reporter
+}
 
-func (c *OSValidator) Name() string {
+func (o *OSValidator) Name() string {
 	return "os"
 }
 
-func (c *OSValidator) Validate(spec SysSpec) error {
-	out, err := exec.Command("uname").CombinedOutput()
+func (o *OSValidator) Validate(spec SysSpec) error {
+	os, err := exec.Command("uname").CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("failed to get os name: %v", err)
 	}
-	return c.validateOS(strings.TrimSpace(string(out)), spec.OS)
+	return o.validateOS(strings.TrimSpace(string(os)), spec.OS)
 }
 
-func (c *OSValidator) validateOS(os, specOS string) error {
+func (o *OSValidator) validateOS(os, specOS string) error {
 	if os != specOS {
-		report("OS", os, bad)
+		o.Reporter.Report("OS", os, bad)
 		return fmt.Errorf("unsupported operating system: %s", os)
 	}
-	report("OS", os, good)
+	o.Reporter.Report("OS", os, good)
 	return nil
 }

test/e2e_node/system/os_validator_test.go

@@ -23,7 +23,9 @@ import (
 )
 
 func TestValidateOS(t *testing.T) {
-	v := &OSValidator{}
+	v := &OSValidator{
+		Reporter: DefaultReporter,
+	}
 	specOS := "Linux"
 	for _, test := range []struct {
 		os  string

test/e2e_node/system/report.go

@@ -18,20 +18,22 @@ package system
 
 import (
 	"fmt"
+	"io"
+	"os"
 )
 
-// resultType is type of the validation result. Different validation results
+// ValidationResultType is type of the validation result. Different validation results
 // corresponds to different colors.
-type resultType int
+type ValidationResultType int32
 
 const (
-	good resultType = iota
+	good ValidationResultType = iota
 	bad
 	warn
 )
 
 // color is the color of the message.
-type color int
+type color int32
 
 const (
 	red    color = 31
@@ -40,15 +42,19 @@ const (
 	white        = 37
 )
 
-func wrap(s string, c color) string {
+func colorize(s string, c color) string {
 	return fmt.Sprintf("\033[0;%dm%s\033[0m", c, s)
 }
 
-// report reports "item: r". item is white, and the color of r depends on the
-// result type.
-func report(item, r string, t resultType) {
+// The default reporter for the system verification test
+type StreamReporter struct {
+	// The stream that this reporter is writing to
+	WriteStream io.Writer
+}
+
+func (dr *StreamReporter) Report(key, value string, resultType ValidationResultType) error {
 	var c color
-	switch t {
+	switch resultType {
 	case good:
 		c = green
 	case bad:
@@ -58,5 +64,15 @@ func report(item, r string, t resultType) {
 	default:
 		c = white
 	}
-	fmt.Printf("%s: %s\n", wrap(item, white), wrap(r, c))
+	if dr.WriteStream == nil {
+		return fmt.Errorf("WriteStream has to be defined for this reporter")
+	}
+
+	fmt.Fprintf(dr.WriteStream, "%s: %s\n", colorize(key, white), colorize(value, c))
+	return nil
+}
+
+// DefaultReporter is the default Reporter
+var DefaultReporter = &StreamReporter{
+	WriteStream: os.Stdout,
 }

test/e2e_node/system/validators.go

@@ -29,21 +29,31 @@ type Validator interface {
 	Validate(SysSpec) error
 }
 
-// validators are all the validators.
-var validators = []Validator{
-	&OSValidator{},
-	&KernelValidator{},
-	&CgroupsValidator{},
-	&DockerValidator{},
+// Reporter is the interface for the reporters for the validators.
+type Reporter interface {
+	// Report reports the results of the system verification
+	Report(string, string, ValidationResultType) error
 }
 
 // Validate uses all validators to validate the system.
-func Validate() error {
+func Validate(spec SysSpec, report Reporter) error {
 	var errs []error
-	spec := DefaultSysSpec
+	// validators are all the validators.
+	var validators = []Validator{
+		&OSValidator{Reporter: report},
+		&KernelValidator{Reporter: report},
+		&CgroupsValidator{Reporter: report},
+		&DockerValidator{Reporter: report},
+	}
+
 	for _, v := range validators {
 		glog.Infof("Validating %s...", v.Name())
 		errs = append(errs, v.Validate(spec))
 	}
 	return errors.NewAggregate(errs)
 }
+
+// ValidateDefault uses all default validators to validate the system and writes to stdout.
+func ValidateDefault() error {
+	return Validate(DefaultSysSpec, DefaultReporter)
+}