update default creds (#4684)

* move logic of default func to configure

* move multiEnvSearch to utils

mmv1/third_party/terraform/utils/provider.go.erb

@@ -25,20 +25,12 @@ func Provider() *schema.Provider {
 			"credentials": &schema.Schema{
 				Type:     schema.TypeString,
 				Optional: true,
-				DefaultFunc: schema.MultiEnvDefaultFunc([]string{
-					"GOOGLE_CREDENTIALS",
-					"GOOGLE_CLOUD_KEYFILE_JSON",
-					"GCLOUD_KEYFILE_JSON",
-				}, nil),
 				ValidateFunc: validateCredentials,
 			},
 
 			"access_token": {
 				Type:     schema.TypeString,
 				Optional: true,
-				DefaultFunc: schema.MultiEnvDefaultFunc([]string{
-					"GOOGLE_OAUTH_ACCESS_TOKEN",
-				}, nil),
 				ConflictsWith: []string{"credentials"},
 			},
 			"impersonate_service_account": {
@@ -510,6 +502,18 @@ func providerConfigure(ctx context.Context, d *schema.ResourceData, p *schema.Pr
 			return nil, diag.FromErr(err)
 		}
 	}
+
+	// Search for default credentials
+	config.Credentials = multiEnvSearch([]string{
+		"GOOGLE_CREDENTIALS",
+		"GOOGLE_CLOUD_KEYFILE_JSON",
+		"GCLOUD_KEYFILE_JSON",
+	})
+
+	config.AccessToken = multiEnvSearch([]string{
+		"GOOGLE_OAUTH_ACCESS_TOKEN",
+	})
+
 	// Add credential source
 	if v, ok := d.GetOk("access_token"); ok {
 		config.AccessToken = v.(string)

mmv1/third_party/terraform/utils/provider_test.go.erb

@@ -938,15 +938,6 @@ func getTestServiceAccountFromEnv(t *testing.T) string {
 	return multiEnvSearch(serviceAccountEnvVars)
 }
 
-func multiEnvSearch(ks []string) string {
-	for _, k := range ks {
-		if v := os.Getenv(k); v != "" {
-			return v
-		}
-	}
-	return ""
-}
-
 // Some tests fail during VCR. One common case is race conditions when creating resources.
 // If a test config adds two fine-grained resources with the same parent it is undefined
 // which will be created first, causing VCR to fail ~50% of the time

mmv1/third_party/terraform/utils/utils.go.erb

@@ -486,3 +486,12 @@ func SnakeToPascalCase(s string) (string) {
 	}
 	return strings.Join(split, "")
 }
+
+func multiEnvSearch(ks []string) string {
+	for _, k := range ks {
+		if v := os.Getenv(k); v != "" {
+			return v
+		}
+	}
+	return ""
+}