ircd: Add distinct maintenance mode; chain write-avoid/read-only and net listen modes.

construct/construct.cc

@@ -472,13 +472,15 @@ enable_coredumps()
 void
 applyargs()
 {
-	if(single)
+	if(single && !bootstrap)
 	{
-		nolisten = true;
-		write_avoid = true;
+		ircd::write_avoid.set("true");
 		cmdline = true;
 	}
 
+	if(bootstrap)
+		ircd::maintenance.set("true");
+
 	if(defaults)
 		ircd::defaults.set("true");
 

include/ircd/ircd.h

@@ -111,11 +111,13 @@ namespace ircd
 	extern const info::versions version_api;
 	extern const info::versions version_abi;
 
+	// Operating Mode Selectors
 	extern conf::item<bool> restart;
 	extern conf::item<bool> debugmode;
-	extern conf::item<bool> read_only;
-	extern conf::item<bool> write_avoid;
+	extern conf::item<bool> maintenance;
 	extern conf::item<bool> soft_assert;
+	extern conf::item<bool> write_avoid;     // implies maintenance
+	extern conf::item<bool> read_only;       // implies write_avoid
 	extern conf::item<bool> defaults;
 
 	// Informational

ircd/ircd.cc

@@ -41,6 +41,33 @@ ircd::version_abi
 	"IRCd", info::versions::ABI, 0, {0, 0, 0}, ircd::info::version
 };
 
+/// Courtesy indicator; this item allows the library to indicate to the
+/// embedder that they should restart their application (or reload this library
+/// if available). The use-case here is for features like the `restart` command
+/// in the console module. Such a command triggers a normal quit and the
+/// application may exit normally; therefor the embedder should check this
+/// item to perform a restart rather than exiting.
+decltype(ircd::restart)
+ircd::restart
+{
+	{ "name",     "ircd.restart"       },
+	{ "default",  false                },
+	{ "persist",  false                },
+};
+
+/// Coarse mode indicator for debug/developer behavior when and if possible.
+/// For example: additional log messages may be enabled by this mode. This
+/// option is technically effective in both release builds and debug builds
+/// but it controls far less in non-debug builds. This item may be toggled
+/// at any time. It doesn't change operational functionality.
+decltype(ircd::debugmode)
+ircd::debugmode
+{
+	{ "name",     "ircd.debugmode"     },
+	{ "default",  false                },
+	{ "persist",  false                },
+};
+
 /// When assertions are enabled this further softens runtime behavior to be
 /// non-disruptive/non-terminating for diagnostic purposes. Debugging/developer
 /// use only. This item may be toggled at any time.
@@ -52,6 +79,26 @@ ircd::soft_assert
 	{ "persist",  false                },
 };
 
+/// Coarse mode declaration for "maintenance mode" a.k.a. "single user mode"
+/// which is intended to be similar to normal operating mode but without
+/// services to clients or some background tasks. It is implied and set when
+/// write_avoid=true which is itself implied and set by read_only.
+decltype(ircd::maintenance)
+ircd::maintenance
+{
+	{
+		{ "name",     "ircd.maintenance"   },
+		{ "default",  false                },
+		{ "persist",  false                },
+	}, []
+	{
+		if(!maintenance)
+			return;
+
+		net::listen.set("false");
+	}
+};
+
 /// Coarse mode indicator for degraded operation known as "write-avoid" which
 /// is similar to read_only but not hard-enforced. Writes may still occur,
 /// such as those manually triggered by an admin. All subsystems and background
@@ -59,9 +106,18 @@ ircd::soft_assert
 decltype(ircd::write_avoid)
 ircd::write_avoid
 {
-	{ "name",     "ircd.write_avoid"   },
-	{ "default",  false                },
-	{ "persist",  false                },
+	{
+		{ "name",     "ircd.write_avoid"   },
+		{ "default",  false                },
+		{ "persist",  false                },
+	}, []
+	{
+		if(!write_avoid)
+			return;
+
+		maintenance.set("true");
+		db::auto_compact.set("false");
+	}
 };
 
 /// Coarse mode declaration for read-only behavior. All subsystems and feature
@@ -71,30 +127,17 @@ ircd::write_avoid
 decltype(ircd::read_only)
 ircd::read_only
 {
-	{ "name",     "ircd.read_only"     },
-	{ "default",  false                },
-	{ "persist",  false                },
-};
+	{
+		{ "name",     "ircd.read_only"     },
+		{ "default",  false                },
+		{ "persist",  false                },
+	}, []
+	{
+		if(!read_only)
+			return;
 
-/// Coarse mode indicator for debug/developer behavior when and if possible.
-/// For example: additional log messages may be enabled by this mode. This
-/// option is technically effective in both release builds and debug builds
-/// but it controls far less in non-debug builds. This item may be toggled
-/// at any time.
-decltype(ircd::debugmode)
-ircd::debugmode
-{
-	{ "name",     "ircd.debugmode"     },
-	{ "default",  false                },
-	{ "persist",  false                },
-};
-
-decltype(ircd::restart)
-ircd::restart
-{
-	{ "name",     "ircd.restart"       },
-	{ "default",  false                },
-	{ "persist",  false                },
+		write_avoid.set("true");
+	}
 };
 
 /// Main context pointer placement.

ircd/logger.cc

@@ -136,7 +136,7 @@ ircd::log::init()
 		console_disable(level::DWARNING);
 	}
 
-	if(!ircd::write_avoid || ircd::debugmode)
+	if(!ircd::write_avoid)
 	{
 		mkdir();
 		open();

matrix/homeserver.cc

@@ -261,7 +261,6 @@ try
 	const bool need_bootstrap
 	{
 		(sequence(*dbs::events) == 0 || opts->bootstrap_vector_path)
-		&& !ircd::write_avoid
 		&& dbs::events
 	};
 
@@ -271,13 +270,14 @@ try
 	mods::imports.emplace("net_dns_cache"s, "net_dns_cache"s);
 
 	if(!ircd::write_avoid)
-	{
 		if(key && !key->verify_keys.empty())
 			m::keys::cache::set(key->verify_keys);
 
+	if(!ircd::maintenance)
 		signon(*this);
+
+	if(!ircd::maintenance)
 		m::init::backfill::init();
-	}
 }
 catch(const std::exception &e)
 {
@@ -304,7 +304,7 @@ noexcept try
 	server::init::wait();
 	m::sync::pool.join();
 
-	if(!ircd::write_avoid && _vm)
+	if(!ircd::maintenance && _vm)
 		signoff(*this);
 
 	///TODO: XXX primary
@@ -826,7 +826,7 @@ ircd::m::offline_status_msg
 void
 ircd::m::signon(homeserver &homeserver)
 {
-	if(!ircd::write_avoid && vm::sequence::retired != 0)
+	if(vm::sequence::retired != 0)
 		presence::set(homeserver.self, "online", online_status_msg);
 }
 
@@ -834,7 +834,7 @@ void
 ircd::m::signoff(homeserver &homeserver)
 noexcept try
 {
-	if(!std::uncaught_exceptions() && !ircd::write_avoid && vm::sequence::retired != 0)
+	if(!std::uncaught_exceptions() && vm::sequence::retired != 0)
 		presence::set(homeserver.self, "offline", offline_status_msg);
 }
 catch(const std::exception &e)

matrix/init_backfill.cc

@@ -114,16 +114,6 @@ ircd::m::init::backfill::init()
 		return;
 	}
 
-	if(ircd::read_only || ircd::write_avoid)
-	{
-		log::warning
-		{
-			log, "Not performing initial backfill because write-avoid flag is set."
-		};
-
-		return;
-	}
-
 	assert(!worker_context);
 	worker_context.reset(new context
 	{