Add integration test for the OIDC discovery endpoint

- Intended to be a red test in this commit; will make it go
  green in a future commit
- Enhance env.go and prepare-for-integration-tests.sh to make it
  possible to write integration tests for the supervisor app
  by setting more env vars and by exposing the service to the kind
  host on a localhost port
- Add `--clean` option to prepare-for-integration-tests.sh
  to make it easier to start fresh
- Make prepare-for-integration-tests.sh advise you to run
  `go test -v -count 1 ./test/integration` because this does
  not buffer the test output
- Make concierge_api_discovery_test.go pass by adding expectations
  for the new OIDCProviderConfig type

test/library/env.go

@@ -25,11 +25,14 @@ const (
 type TestEnv struct {
 	t *testing.T
 
-	Namespace    string                                  `json:"namespace"`
-	AppName      string                                  `json:"appName"`
-	Capabilities map[TestClusterCapability]bool          `json:"capabilities"`
-	TestWebhook  idpv1alpha1.WebhookIdentityProviderSpec `json:"testWebhook"`
-	TestUser     struct {
+	Namespace           string                                  `json:"namespace"`
+	SupervisorNamespace string                                  `json:"supervisorNamespace"`
+	AppName             string                                  `json:"appName"`
+	SupervisorAppName   string                                  `json:"supervisorAppName"`
+	Capabilities        map[TestClusterCapability]bool          `json:"capabilities"`
+	TestWebhook         idpv1alpha1.WebhookIdentityProviderSpec `json:"testWebhook"`
+	SupervisorAddress   string                                  `json:"supervisorAddress"`
+	TestUser            struct {
 		Token            string   `json:"token"`
 		ExpectedUsername string   `json:"expectedUsername"`
 		ExpectedGroups   []string `json:"expectedGroups"`
@@ -71,6 +74,9 @@ func IntegrationEnv(t *testing.T) *TestEnv {
 	result.TestUser.ExpectedGroups = strings.Split(strings.ReplaceAll(needEnv("PINNIPED_TEST_USER_GROUPS"), " ", ""), ",")
 	result.TestUser.Token = needEnv("PINNIPED_TEST_USER_TOKEN")
 	result.TestWebhook.Endpoint = needEnv("PINNIPED_TEST_WEBHOOK_ENDPOINT")
+	result.SupervisorNamespace = needEnv("PINNIPED_SUPERVISOR_NAMESPACE")
+	result.SupervisorAppName = needEnv("PINNIPED_SUPERVISOR_APP_NAME")
+	result.SupervisorAddress = needEnv("PINNIPED_TEST_SUPERVISOR_ADDRESS")
 	result.TestWebhook.TLS = &idpv1alpha1.TLSSpec{CertificateAuthorityData: needEnv("PINNIPED_TEST_WEBHOOK_CA_BUNDLE")}
 	result.t = t
 	return &result