The RunServer() function (and the various variants)
call Server.Start() in a go-routine, but do not return until
it has verified that the server is ready to accept connections.
To do so, it use GetListenEndpoint() to get a suitable connect
address (replacing "0.0.0.0" or "::" with localhost - important
on Windows). It then creates a raw TCP connection to ensure the
server is started, repeating the process in case of failure up
to 10 seconds.
This PR replaces this with a function that checks that client
listener, and route listener if configured, are set. This removes
the need to get a connect address and create test tcp connections.
The reason for this change is that NATS Streaming when starting
the NATS Server (unless configured to connect to a remote one)
calls RunServerWithAuth(), which when getting "localhost" from
GetListenEndpoint(), would fail trying to resolve it. This happened
for the NATS Streaming Docker image built with Go 1.7+.
By default, a server is now sending to its clients the client URLs
of all servers in the cluster. This allows clients to be able
to reconnect to any server in the cluster even if those clients
were not configured with the list of servers in the cluster.
However, there may be cases where it would make sense to disable
this feature. This now can be done with this option/command line
parameter.
Resolves#322
Clients that will be at the ClientProtoInfo protocol level (or above)
will now receive an asynchronous INFO protocol when the server
they connect to adds a *new* route. This means that when the cluster
adds a new server, all clients in the cluster should now be notified
of this new addition.
Both seed and chained cases are now handled properly when servers
connect quickly and concurrently to one another.
When accepting a route, the server will forward the new route INFO
protocol to its known routes. In turn those routes will connect
to the new server (if not already connected).
A retry for implicit route was introduced to mitigate the issue
with two servers connecting to each other and electing the opposite
connection as the winner, resulting in both connections being dropped.
The server with smaller ID will try once to reconnect.
Some tests were fixed to handle possible extra INFO protocol.
New tests added.
Fix issue: https://github.com/nats-io/gnatsd/issues/206
Attempt to address issue #175.
Instead of trying to detect if route URL will point to route listen address, detects that the route remoteID is server's ID.
If so, closes the connection and stop trying.
- The raw connection used to check that the server is started now consumes the INFO and sends PING and consumes PONG before returning.
- The route test needs to make sure that the client connection has client id 2. Using PING/PONG before creating route connection to make sure of that.
