WebServer: Require document root and credentials as config init params

Now, there is nothing that can react to `set_...()` calls, so
offering this possibility can cause wrong assumptions as to what one
can do as soon as a WebServer instance has launched.

The main program can still decide whether to supply the optional
credentials or not, but this way, the configuration can become a Value
Object that won't change after initial creation.

Userland/Services/WebServer/Configuration.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
+ * Copyright (c) 2022, Thomas Keppler <serenity@tkeppler.de>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -10,8 +11,9 @@ namespace WebServer {
 
 static Configuration* s_configuration = nullptr;
 
-Configuration::Configuration(DeprecatedString document_root_path)
+Configuration::Configuration(DeprecatedString document_root_path, Optional<HTTP::HttpRequest::BasicAuthenticationCredentials> credentials)
     : m_document_root_path(move(document_root_path))
+    , m_credentials(move(credentials))
 {
     VERIFY(!s_configuration);
     s_configuration = this;

Userland/Services/WebServer/Configuration.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
+ * Copyright (c) 2022, Thomas Keppler <serenity@tkeppler.de>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -14,14 +15,11 @@ namespace WebServer {
 
 class Configuration {
 public:
-    Configuration(DeprecatedString document_root_path);
+    Configuration(DeprecatedString document_root_path, Optional<HTTP::HttpRequest::BasicAuthenticationCredentials> credentials = {});
 
     DeprecatedString const& document_root_path() const { return m_document_root_path; }
     Optional<HTTP::HttpRequest::BasicAuthenticationCredentials> const& credentials() const { return m_credentials; }
 
-    void set_document_root_path(DeprecatedString root_path) { m_document_root_path = move(root_path); }
-    void set_credentials(Optional<HTTP::HttpRequest::BasicAuthenticationCredentials> credentials) { m_credentials = move(credentials); }
-
     static Configuration const& the();
 
 private:

Userland/Services/WebServer/main.cpp

@@ -55,7 +55,6 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     auto real_document_root_path = Core::File::real_path_for(document_root_path);
-
     if (!Core::File::exists(real_document_root_path)) {
         warnln("Root path does not exist: '{}'", document_root_path);
         return 1;
@@ -63,10 +62,11 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     TRY(Core::System::pledge("stdio accept rpath inet unix"));
 
-    WebServer::Configuration configuration(real_document_root_path);
-
+    Optional<HTTP::HttpRequest::BasicAuthenticationCredentials> credentials;
     if (!username.is_empty() && !password.is_empty())
-        configuration.set_credentials(HTTP::HttpRequest::BasicAuthenticationCredentials { username, password });
+        credentials = HTTP::HttpRequest::BasicAuthenticationCredentials { username, password };
+
+    WebServer::Configuration configuration(real_document_root_path, credentials);
 
     Core::EventLoop loop;