API Version preflight check for sonobuoy run (#339)

* API Version preflight check for sonobuoy run
* Add version deps

Signed-off-by: liz <liz@heptio.com>

cmd/sonobuoy/app/e2e.go

@@ -104,6 +104,16 @@ func e2es(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 
+	if !e2eflags.skipPreflight {
+		if errs := sonobuoy.PreflightChecks(); len(errs) > 0 {
+			errlog.LogError(errors.New("Preflight checks failed"))
+			for _, err := range errs {
+				errlog.LogError(err)
+			}
+			os.Exit(1)
+		}
+	}
+
 	fmt.Printf("Rerunning %d tests:\n", len(testCases))
 	if err := sonobuoy.Run(cfg); err != nil {
 		errlog.LogError(errors.Wrap(err, "error attempting to rerun failed tests"))

cmd/sonobuoy/app/run.go

@@ -50,8 +50,7 @@ func (r *runFlags) Config() (*ops.RunConfig, error) {
 		return nil, err
 	}
 	return &ops.RunConfig{
-		GenConfig:     *gencfg,
-		SkipPreflight: r.skipPreflight,
+		GenConfig: *gencfg,
 	}, nil
 }
 
@@ -85,6 +84,7 @@ func submitSonobuoyRun(cmd *cobra.Command, args []string) {
 		errlog.LogError(errors.Wrap(err, "could not create sonobuoy client"))
 		os.Exit(1)
 	}
+
 	m := genflags.mode.Get()
 	plugins := []string{}
 	for _, plugin := range m.Selectors {
@@ -93,6 +93,17 @@ func submitSonobuoyRun(cmd *cobra.Command, args []string) {
 	if len(plugins) > 0 {
 		fmt.Printf("Running plugins: %v\n", strings.Join(plugins, ", "))
 	}
+
+	if !runflags.skipPreflight {
+		if errs := sbc.PreflightChecks(); len(errs) > 0 {
+			errlog.LogError(errors.New("Preflight checks failed"))
+			for _, err := range errs {
+				errlog.LogError(err)
+			}
+			os.Exit(1)
+		}
+	}
+
 	if err := sbc.Run(cfg); err != nil {
 		errlog.LogError(errors.Wrap(err, "error attempting to run sonobuoy"))
 		os.Exit(1)

pkg/buildinfo/version.go

@@ -24,3 +24,9 @@ var Version = "v0.11.0-alpha"
 
 // DockerImage is the full path to the docker image for this build, example gcr.io/heptio-images/sonobuoy
 var DockerImage string
+
+// MinimumKubeVersion is the lowest API version of Kubernetes this release of Sonobuoy supports.
+var MinimumKubeVersion = "1.8.0"
+
+// MaximumKubeVersion is the highest API version of Kubernetes this release of Sonobuoy supports.
+var MaximumKubeVersion = "1.11.0"

pkg/client/defaults.go

@@ -37,8 +37,7 @@ func NewGenConfig() *GenConfig {
 // NewRunConfig is a RunConfig with DefaultGenConfig and and preflight checks enabled.
 func NewRunConfig() *RunConfig {
 	return &RunConfig{
-		GenConfig:     *NewGenConfig(),
-		SkipPreflight: false,
+		GenConfig: *NewGenConfig(),
 	}
 }
 

pkg/client/interfaces.go

@@ -56,8 +56,6 @@ type E2EConfig struct {
 // RunConfig are the input options for running Sonobuoy.
 type RunConfig struct {
 	GenConfig
-	// SkipPreflight means don't run any checks before kicking off the Sonobuoy run.
-	SkipPreflight bool
 }
 
 // DeleteConfig are the input options for cleaning up a Sonobuoy run.
@@ -130,4 +128,6 @@ type Interface interface {
 	LogReader(cfg *LogConfig) (*Reader, error)
 	// Delete removes a sonobuoy run, namespace, and all associated resources.
 	Delete(cfg *DeleteConfig) error
+	// PreflightChecks runs a number of preflight checks to confirm the environment is good for Sonobuoy
+	PreflightChecks() []error
 }

pkg/client/preflight.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2018 Heptio Inc.
+
+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 client
+
+import (
+	"fmt"
+
+	version "github.com/hashicorp/go-version"
+	"github.com/heptio/sonobuoy/pkg/buildinfo"
+	"github.com/pkg/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+)
+
+var preflightChecks = []func(kubernetes.Interface) error{
+	preflightDNSCheck,
+	preflightVersionCheck,
+}
+
+// PreflightChecks runs all preflight checks in order, returning the first error encountered.
+func (c *SonobuoyClient) PreflightChecks() []error {
+	client, err := c.Client()
+	if err != nil {
+		return []error{err}
+	}
+
+	errors := []error{}
+
+	for _, check := range preflightChecks {
+		if err := check(client); err != nil {
+			errors = append(errors, err)
+		}
+	}
+	return errors
+}
+
+const (
+	kubeSystemNamespace = "kube-system"
+	kubeDNSLabelKey     = "k8s-app"
+	kubeDNSLabelValue   = "kube-dns"
+)
+
+func preflightDNSCheck(client kubernetes.Interface) error {
+	selector := metav1.AddLabelToSelector(&metav1.LabelSelector{}, kubeDNSLabelKey, kubeDNSLabelValue)
+
+	obj, err := client.CoreV1().Pods(kubeSystemNamespace).List(
+		metav1.ListOptions{LabelSelector: metav1.FormatLabelSelector(selector)},
+	)
+	if err != nil {
+		return errors.Wrap(err, "could not retrieve list of pods")
+	}
+
+	if len(obj.Items) == 0 {
+		return errors.New("no kube-dns tests found")
+	}
+
+	return nil
+}
+
+var (
+	minimumKubeVersion = version.Must(version.NewVersion(buildinfo.MinimumKubeVersion))
+	maximumKubeVersion = version.Must(version.NewVersion(buildinfo.MaximumKubeVersion))
+)
+
+func preflightVersionCheck(client kubernetes.Interface) error {
+	versionInfo, err := client.Discovery().ServerVersion()
+	if err != nil {
+		return errors.Wrap(err, "failed to retrieve server version")
+	}
+
+	serverVersion, err := version.NewVersion(versionInfo.String())
+	if err != nil {
+		return errors.Wrap(err, "couldn't parse version string")
+	}
+
+	if serverVersion.LessThan(minimumKubeVersion) {
+		return fmt.Errorf("Minimum kubernetes version is %s, got %s", minimumKubeVersion.String(), versionInfo.String())
+	}
+
+	if serverVersion.GreaterThan(maximumKubeVersion) {
+		return fmt.Errorf("Maximum kubernetes version is %s, got %s", maximumKubeVersion.String(), versionInfo.String())
+	}
+
+	return nil
+}

pkg/client/run.go

@@ -31,25 +31,13 @@ import (
 	"k8s.io/apimachinery/pkg/util/yaml"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
-	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 )
 
 const bufferSize = 4096
 
 func (c *SonobuoyClient) Run(cfg *RunConfig) error {
-	client, err := c.Client()
-	if err != nil {
-		return err
-	}
-
-	if !cfg.SkipPreflight {
-		if err := preflightCheck(client); err != nil {
-			return errors.Wrap(err, "preflight check failed")
-		}
-	}
-
 	manifest, err := c.GenerateManifest(&cfg.GenConfig)
 	if err != nil {
 		return errors.Wrap(err, "couldn't run invalid manifest")
@@ -176,26 +164,3 @@ func unstructuredVersionInterface(version schema.GroupVersion) (*meta.VersionInt
 		MetadataAccessor: meta.NewAccessor(),
 	}, nil
 }
-
-const (
-	kubeSystemNamespace = "kube-system"
-	kubeDNSLabelKey     = "k8s-app"
-	kubeDNSLabelValue   = "kube-dns"
-)
-
-func preflightCheck(client kubernetes.Interface) error {
-	selector := metav1.AddLabelToSelector(&metav1.LabelSelector{}, kubeDNSLabelKey, kubeDNSLabelValue)
-
-	obj, err := client.CoreV1().Pods(kubeSystemNamespace).List(
-		metav1.ListOptions{LabelSelector: metav1.FormatLabelSelector(selector)},
-	)
-	if err != nil {
-		return errors.Wrap(err, "could not retrieve list of pods")
-	}
-
-	if len(obj.Items) == 0 {
-		return errors.New("no kube-dns tests found")
-	}
-
-	return nil
-}