storage/kubernetes: don't guess the kubeconfig location and change test env

Using the default KUBECONFIG environment variable to indicate that
the Kubernetes tests should be run lead to cases where developers
accidentally ran the tests. This has now been changed to
"DEX_KUBECONFIG" and documentation hsa been added detailing how to
run these tests.

Additionally, no other storage reads environment variables for its
normal configuration (outside of tests) so the Kubernetes storage
no longer does.

Overall, be less surprising.

Documentation/dev-running-db-tests.md → Documentation/dev-integration-tests.md

-# Running database tests
+# Running integration tests
+
+## Kubernetes
+
+Kubernetes tests will only run if the `DEX_KUBECONFIG` environment variable is set.
+
+```
+$ export DEX_KUBECONFIG=~/.kube/config
+$ go test -v -i ./storage/kubernetes
+$ go test -v ./storage/kubernetes
+```
+
+Because third party resources creation isn't synchronized it's expected that the tests fail the first time. Fear not, and just run them again.
+
+## Postgres
 
 Running database tests locally require:
 
 * A systemd based Linux distro.
 * A recent version of [rkt](https://github.com/coreos/rkt) installed.
 
-The `standup.sh` script in the SQL directory is used to run databases in
-containers with systemd daemonizing the process.
+The `standup.sh` script in the SQL directory is used to run databases in containers with systemd daemonizing the process.
 
 ```
 $ sudo ./storage/sql/standup.sh create postgres
@@ -21,11 +34,10 @@ To run tests export the following environment variables:
 
 ```
 
-Exporting the variables will cause the database tests to be run, rather than
-skipped.
+Exporting the variables will cause the database tests to be run, rather than skipped.
 
 ```
-$ # sqlite takes forever to compile, be sure to install test dependencies
+$ # sqlite3 takes forever to compile, be sure to install test dependencies
 $ go test -v -i ./storage/sql
 $ go test -v ./storage/sql
 ```

glide.lock

-hash: 8b7a5f94584ecd144fc3ce94bb0b09f8e96c94b5a8e10d5053bd24bb597367ce
-updated: 2016-10-03T23:25:41.280181088-07:00
+hash: a813cbca07393d7cbe35d411cdef588afac7a3bab8a287ffe7b9587516ef5898
+updated: 2016-10-23T20:51:55.313818678-07:00
 imports:
 - name: github.com/cockroachdb/cockroach-go
   version: 31611c0501c812f437d4861d87d117053967c955
@@ -33,8 +33,6 @@ imports:
   - oid
 - name: github.com/mattn/go-sqlite3
   version: 3fb7a0e792edd47bf0cf1e919dfc14e2be412e15
-- name: github.com/mitchellh/go-homedir
-  version: 756f7b183b7ab78acdbbee5c7f392838ed459dda
 - name: github.com/pquerna/cachecontrol
   version: c97913dcbd76de40b051a9b4cd827f7eaeb7a868
   subpackages:

glide.yaml

@@ -74,9 +74,6 @@ import:
   - proto
   - protoc-gen-go
 
-- package: github.com/mitchellh/go-homedir
-  verison: 756f7b183b7ab78acdbbee5c7f392838ed459dda
-
 - package: github.com/kylelemons/godebug
   subpackages:
   - diff

storage/kubernetes/storage.go

@@ -5,11 +5,8 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	"os"
-	"path/filepath"
 	"time"
 
-	homedir "github.com/mitchellh/go-homedir"
 	"golang.org/x/net/context"
 
 	"github.com/coreos/dex/storage"
@@ -37,8 +34,7 @@ const (
 // Config values for the Kubernetes storage type.
 type Config struct {
 	InCluster      bool   `yaml:"inCluster"`
-	KubeConfigPath string `yaml:"kubeConfigPath"`
-	GCFrequency    int64  `yaml:"gcFrequency"` // seconds
+	KubeConfigFile string `yaml:"kubeConfigFile"`
 }
 
 // Open returns a storage using Kubernetes third party resource.
@@ -52,8 +48,11 @@ func (c *Config) Open() (storage.Storage, error) {
 
 // open returns a client with no garbage collection.
 func (c *Config) open() (*client, error) {
-	if c.InCluster && (c.KubeConfigPath != "") {
-		return nil, errors.New("cannot specify both 'inCluster' and 'kubeConfigPath'")
+	if c.InCluster && (c.KubeConfigFile != "") {
+		return nil, errors.New("cannot specify both 'inCluster' and 'kubeConfigFile'")
+	}
+	if !c.InCluster && (c.KubeConfigFile == "") {
+		return nil, errors.New("must specify either 'inCluster' or 'kubeConfigFile'")
 	}
 
 	var (
@@ -65,18 +64,7 @@ func (c *Config) open() (*client, error) {
 	if c.InCluster {
 		cluster, user, namespace, err = inClusterConfig()
 	} else {
-		kubeConfigPath := c.KubeConfigPath
-		if kubeConfigPath == "" {
-			kubeConfigPath = os.Getenv("KUBECONFIG")
-		}
-		if kubeConfigPath == "" {
-			p, err := homedir.Dir()
-			if err != nil {
-				return nil, fmt.Errorf("finding homedir: %v", err)
-			}
-			kubeConfigPath = filepath.Join(p, ".kube", "config")
-		}
-		cluster, user, namespace, err = loadKubeConfig(kubeConfigPath)
+		cluster, user, namespace, err = loadKubeConfig(c.KubeConfigFile)
 	}
 	if err != nil {
 		return nil, err

storage/kubernetes/storage_test.go

@@ -8,15 +8,19 @@ import (
 	"github.com/coreos/dex/storage/conformance"
 )
 
+const testKubeConfigEnv = "DEX_KUBECONFIG"
+
 func TestLoadClient(t *testing.T) {
 	loadClient(t)
 }
 
 func loadClient(t *testing.T) *client {
-	if os.Getenv("KUBECONFIG") == "" {
-		t.Skip()
+	config := Config{
+		KubeConfigFile: os.Getenv(testKubeConfigEnv),
+	}
+	if config.KubeConfigFile == "" {
+		t.Skipf("test environment variable %q not set, skipping", testKubeConfigEnv)
 	}
-	var config Config
 	s, err := config.open()
 	if err != nil {
 		t.Fatal(err)