From a26cbbf3d043c8f6bbc89bb1f515e73a2eedad8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucas=20K=C3=A4ldstr=C3=B6m?=
 <lucas.kaldstrom@hotmail.co.uk>
Date: Sat, 12 Nov 2016 16:37:12 +0200
Subject: [PATCH] Add the system verification check to the kubeadm preflight
 checks

---
 cmd/kubeadm/app/preflight/BUILD     |  1 +
 cmd/kubeadm/app/preflight/checks.go | 23 +++++++++++++++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/cmd/kubeadm/app/preflight/BUILD b/cmd/kubeadm/app/preflight/BUILD
index 69051be0514..d12bc13740b 100644
--- a/cmd/kubeadm/app/preflight/BUILD
+++ b/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",
     ],
 )
 
diff --git a/cmd/kubeadm/app/preflight/checks.go b/cmd/kubeadm/app/preflight/checks.go
index 1b0950745ff..b8142ace558 100644
--- a/cmd/kubeadm/app/preflight/checks.go
+++ b/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"},