P2P: Provide better log message when unable to resolve host

[heifner]

Before:

info  2024-08-12T16:20:02.907 net-1     net_plugin.cpp:2794           operator()           ] connection failed to p2p.spring-beta.jungletestnet.io:9898, Element not found

After

info  2024-08-12T16:24:02.571 net-2     net_plugin.cpp:2795           operator()           ] connection failed to p2p.spring-beta.jungletestnet.io:9898, Unable to resolve endpoint

[spoonincode]

I'm a little suspicious this isn't the right location for such a test. If we can't resolve any hosts wouldn't this be the right location for handling such a thing?

spring/plugins/net_plugin/net_plugin.cpp

Lines 4611 to 4628 in 0f8bbeb

	resolver->async_resolve(host, port,
	[resolver, host = host, port = port, peer_address = peer_address, listen_address = listen_address, this]( const boost::system::error_code& err, const tcp::resolver::results_type& results ) {
	connection_ptr c = std::make_shared<connection>( peer_address, listen_address );
	c->set_heartbeat_timeout( heartbeat_timeout );
	std::lock_guard g( connections_mtx );
	auto [it, inserted] = connections.emplace( connection_detail{
	.host = peer_address,
	.c = std::move(c),
	.ips = results
	});
	if( !err ) {
	it->c->connect( results );
	} else {
	fc_wlog( logger, "Unable to resolve ${host}:${port} ${error}",
	("host", host)("port", port)( "error", err.message() ) );
	it->c->set_state(connection::connection_state::closed);
	++(it->c->consecutive_immediate_connection_close);
	}

Is it possible when being unable to resolve any hosts async_resolve completes successfully but returns an empty result list? (that seems at odds with documentation, just trying to think how this existing Unable to resolve path isn't getting hit)

[heifner]

Thanks for pointing this out. Seems the issue is that we add the connection to the connections index even if it doesn't resolve. Then we use that .ips for reconnection. Seems instead we should attempt to resolve the host on each new re-connection.

[heifner]

Created a new issue for this: #525. Thanks @spoonincode

[ericpassmore]

Note:start
group: LOGGING
category: CLOSED
summary: Improved log message when unable to resolve host.
Note: end