ircd:Ⓜ️:self: Add the servername string to this section; update README.

README.md

@@ -160,12 +160,19 @@ in your git repo to the library path:
 `export LD_LIBRARY_PATH=/path/to/src/deps/rocksdb:$LD_LIBRARY_PATH`
 
 - We will refer to your server as `host.tld`. For those familiar with matrix:
-this is your origin and mxid `@user:host.tld` hostpart. If your DNS uses
-`matrix.host.tld` that subdomain is not involved when we refer to
-`host.tld` unless we explicitly mention to involve it.
+this is your _origin_ and mxid `@user:host.tld` hostpart. If you delegate
+your server's location to something like `matrix.host.tld:1234` we refer to
+this as your _servername_.
+
+> Construct clusters all share the same _origin_ but each individual instance
+of the daemon has a unique _servername_.
 
 
 1. Execute
+
+	There are two arguments: `<origin> [servername]`. If the _servername_
+	argument is missing, the _origin_ will be used for it instead.
+
 	```
 	bin/construct host.tld
 	````

include/ircd/m/self.h

@@ -16,6 +16,7 @@ namespace ircd::m::self
 	struct init;
 
 	extern std::string origin;
+	extern std::string servername;
 	extern ed25519::sk secret_key;
 	extern ed25519::pk public_key;
 	extern std::string public_key_b64;
@@ -44,7 +45,7 @@ namespace ircd
 
 struct ircd::m::self::init
 {
-	init(const string_view &origin);
+	init(const string_view &origin, const string_view &servername);
 };
 
 inline ircd::string_view

ircd/ircd.cc

@@ -11,7 +11,7 @@
 namespace ircd
 {
 	std::string _origin;                         // user's supplied param
-	std::string _hostname;                       // user's supplied param
+	std::string _servername;                     // user's supplied param
 	ctx::ctx *main_context;                      // Main program loop
 
 	void main() noexcept;
@@ -45,7 +45,7 @@ ircd::restart
 void
 ircd::init(boost::asio::io_context &user_ios,
            const string_view &origin,
-           const string_view &hostname)
+           const string_view &servername)
 try
 {
 	if(run::level != run::level::HALT)
@@ -58,7 +58,7 @@ try
 
 	// Save the params used for m::init later.
 	_origin = std::string{origin};
-	_hostname = std::string{hostname};
+	_servername = std::string{servername};
 
 	// The log is available. but it is console-only until conf opens files.
 	log::init();
@@ -214,7 +214,7 @@ noexcept try
 	m::init _matrix_         // Matrix
 	{
 		string_view{_origin},
-		string_view{_hostname}
+		string_view{_servername}
 	};
 
 	// Any deinits which have to be done with all subsystems intact

ircd/m.cc

@@ -37,11 +37,11 @@ me_offline_status_msg
 //
 
 ircd::m::init::init(const string_view &origin,
-                    const string_view &hostname)
+                    const string_view &servername)
 try
 :_self
 {
-	origin
+	origin, servername
 }
 ,_modules
 {
@@ -278,6 +278,10 @@ std::string
 ircd::m::self::origin
 {};
 
+std::string
+ircd::m::self::servername
+{};
+
 ircd::ed25519::sk
 ircd::m::self::secret_key
 {};
@@ -393,9 +397,11 @@ extern ircd::m::room::id::buf users_room_id;
 extern ircd::m::room::id::buf tokens_room_id;
 extern ircd::m::room::id::buf nodes_room_id;
 
-ircd::m::self::init::init(const string_view &origin)
+ircd::m::self::init::init(const string_view &origin,
+                          const string_view &servername)
 {
-	self::origin = std::string{origin};
+	self::origin = origin;
+	self::servername = servername;
 
 	ircd_user_id = {"ircd", origin};
 	m::me = {ircd_user_id};