Merge pull request #63673 from chuckha/remove-extra-args-check

Automatic merge from submit-queue (batch tested with PRs 63673, 63712). 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>.

Remove ExtraArgs kubeadm preflight check

This check pulled in a number of dependencies that bloated the dep graph.

The feature itself was not worth an extra 500 dependencies so we decided
to remove the feature.

Closes kubernetes/kubeadm#497

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

**What this PR does / why we need it**:
This PR removes a check that was pulling in a lot of external dependencies. We decided the check was not worth the extra dependencies.

**Special notes for your reviewer**:
We might want to keep the first part of the check and only delete the second part, but it was easier to delete the whole thing.

**Release note**:

```release-note
Removes a preflight check for kubeadm that validated custom kube-apiserver, kube-controller-manager and kube-scheduler arguments.
```

cmd/kubeadm/app/preflight/BUILD

@@ -49,9 +49,6 @@ go_library(
     }),
     importpath = "k8s.io/kubernetes/cmd/kubeadm/app/preflight",
     deps = [
-        "//cmd/kube-apiserver/app/options:go_default_library",
-        "//cmd/kube-controller-manager/app/options:go_default_library",
-        "//cmd/kube-scheduler/app:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm/v1alpha1:go_default_library",
         "//cmd/kubeadm/app/constants:go_default_library",
@@ -65,7 +62,6 @@ go_library(
         "//vendor/github.com/PuerkitoBio/purell:go_default_library",
         "//vendor/github.com/blang/semver:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
-        "//vendor/github.com/spf13/pflag:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/net:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/utils/exec:go_default_library",

cmd/kubeadm/app/preflight/checks.go

@@ -38,15 +38,11 @@ import (
 	"github.com/PuerkitoBio/purell"
 	"github.com/blang/semver"
 	"github.com/golang/glog"
-	"github.com/spf13/pflag"
 
 	"net/url"
 
 	netutil "k8s.io/apimachinery/pkg/util/net"
 	"k8s.io/apimachinery/pkg/util/sets"
-	apiservoptions "k8s.io/kubernetes/cmd/kube-apiserver/app/options"
-	cmoptions "k8s.io/kubernetes/cmd/kube-controller-manager/app/options"
-	schedulerapp "k8s.io/kubernetes/cmd/kube-scheduler/app"
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 	kubeadmdefaults "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1alpha1"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
@@ -509,56 +505,6 @@ func (subnet HTTPProxyCIDRCheck) Check() (warnings, errors []error) {
 	return nil, nil
 }
 
-// ExtraArgsCheck checks if arguments are valid.
-type ExtraArgsCheck struct {
-	APIServerExtraArgs         map[string]string
-	ControllerManagerExtraArgs map[string]string
-	SchedulerExtraArgs         map[string]string
-}
-
-// Name will return ExtraArgs as name for ExtraArgsCheck
-func (ExtraArgsCheck) Name() string {
-	return "ExtraArgs"
-}
-
-// Check validates additional arguments of the control plane components.
-func (eac ExtraArgsCheck) Check() (warnings, errors []error) {
-	glog.V(1).Infoln("validating additional arguments of the control plane components")
-	argsCheck := func(name string, args map[string]string, f *pflag.FlagSet) []error {
-		errs := []error{}
-		for k, v := range args {
-			if err := f.Set(k, v); err != nil {
-				errs = append(errs, fmt.Errorf("%s: failed to parse extra argument --%s=%s", name, k, v))
-			}
-		}
-		return errs
-	}
-
-	warnings = []error{}
-	if len(eac.APIServerExtraArgs) > 0 {
-		flags := pflag.NewFlagSet("", pflag.ContinueOnError)
-		s := apiservoptions.NewServerRunOptions()
-		s.AddFlags(flags)
-		warnings = append(warnings, argsCheck("kube-apiserver", eac.APIServerExtraArgs, flags)...)
-	}
-	if len(eac.ControllerManagerExtraArgs) > 0 {
-		flags := pflag.NewFlagSet("", pflag.ContinueOnError)
-		s := cmoptions.NewKubeControllerManagerOptions()
-		s.AddFlags(flags, []string{}, []string{})
-		warnings = append(warnings, argsCheck("kube-controller-manager", eac.ControllerManagerExtraArgs, flags)...)
-	}
-	if len(eac.SchedulerExtraArgs) > 0 {
-		opts, err := schedulerapp.NewOptions()
-		if err != nil {
-			warnings = append(warnings, err)
-		}
-		flags := pflag.NewFlagSet("", pflag.ContinueOnError)
-		opts.AddFlags(flags)
-		warnings = append(warnings, argsCheck("kube-scheduler", eac.SchedulerExtraArgs, flags)...)
-	}
-	return warnings, nil
-}
-
 // SystemVerificationCheck defines struct used for for running the system verification node check in test/e2e_node/system
 type SystemVerificationCheck struct {
 	CRISocket string
@@ -885,11 +831,6 @@ func RunInitMasterChecks(execer utilsexec.Interface, cfg *kubeadmapi.MasterConfi
 		FileAvailableCheck{Path: kubeadmconstants.GetStaticPodFilepath(kubeadmconstants.KubeControllerManager, manifestsDir)},
 		FileAvailableCheck{Path: kubeadmconstants.GetStaticPodFilepath(kubeadmconstants.KubeScheduler, manifestsDir)},
 		FileAvailableCheck{Path: kubeadmconstants.GetStaticPodFilepath(kubeadmconstants.Etcd, manifestsDir)},
-		ExtraArgsCheck{
-			APIServerExtraArgs:         cfg.APIServerExtraArgs,
-			ControllerManagerExtraArgs: cfg.ControllerManagerExtraArgs,
-			SchedulerExtraArgs:         cfg.SchedulerExtraArgs,
-		},
 		HTTPProxyCheck{Proto: "https", Host: cfg.API.AdvertiseAddress},
 		HTTPProxyCIDRCheck{Proto: "https", CIDR: cfg.Networking.ServiceSubnet},
 		HTTPProxyCIDRCheck{Proto: "https", CIDR: cfg.Networking.PodSubnet},

cmd/kubeadm/app/preflight/checks_test.go

@@ -288,17 +288,6 @@ func TestRunChecks(t *testing.T) {
 		{[]Checker{FileContentCheck{Path: "/", Content: []byte("does not exist")}}, false, ""},
 		{[]Checker{InPathCheck{executable: "foobarbaz", exec: exec.New()}}, true, "\t[WARNING FileExisting-foobarbaz]: foobarbaz not found in system path\n"},
 		{[]Checker{InPathCheck{executable: "foobarbaz", mandatory: true, exec: exec.New()}}, false, ""},
-		{[]Checker{ExtraArgsCheck{
-			APIServerExtraArgs:         map[string]string{"secure-port": "1234"},
-			ControllerManagerExtraArgs: map[string]string{"use-service-account-credentials": "true"},
-			SchedulerExtraArgs:         map[string]string{"leader-elect": "true"},
-		}}, true, ""},
-		{[]Checker{ExtraArgsCheck{
-			APIServerExtraArgs: map[string]string{"secure-port": "foo"},
-		}}, true, "\t[WARNING ExtraArgs]: kube-apiserver: failed to parse extra argument --secure-port=foo\n"},
-		{[]Checker{ExtraArgsCheck{
-			APIServerExtraArgs: map[string]string{"invalid-argument": "foo"},
-		}}, true, "\t[WARNING ExtraArgs]: kube-apiserver: failed to parse extra argument --invalid-argument=foo\n"},
 		{[]Checker{InPathCheck{executable: "foobar", mandatory: false, exec: exec.New(), suggestion: "install foobar"}}, true, "\t[WARNING FileExisting-foobar]: foobar not found in system path\nSuggestion: install foobar\n"},
 	}
 	for _, rt := range tokenTest {