Make server jwtSecret configurable

Default to the existing default value, but allow the value to be
overriden by a new experimental config value.

Author: Andrew Farries

install/installer/pkg/components/server/configmap.go

@@ -20,6 +20,12 @@ func configmap(ctx *common.RenderContext) ([]runtime.Object, error) {
 	if err != nil {
 		return nil, err
 	}
+	_ = ctx.WithExperimental(func(cfg *experimental.Config) error {
+		if cfg.WebApp != nil && cfg.WebApp.OAuthServer.JWTSecret != "" {
+			jwtSecret = cfg.WebApp.OAuthServer.JWTSecret
+		}
+		return nil
+	})
 
 	license := ""
 	if ctx.Config.License != nil {

install/installer/pkg/config/v1/experimental/experimental.go

@@ -56,6 +56,9 @@ type WebAppConfig struct {
 	WorkspaceDefaults struct {
 		WorkspaceImage string `json:"workspaceImage"`
 	} `json:"workspaceDefaults"`
+	OAuthServer struct {
+		JWTSecret string `json:"jwtSecret"`
+	} `json:"oauthServer"`
 }
 
 type PublicAPIConfig struct {