SyncServices() immediately attempts to sync whatever information
the process has with Consul. Previously this method would take an
argument of the exclusive list of services that should exist,
however this is not condusive to having a Nomad Client and Nomad
Server share the same consul.Syncer.
I *KNEW* I should have done this when I wrote it, but didn't want to
go back and audit the handlers to include the appropriate return
handling, but now that the code is taking shape, make this change.
Previously this would immediately default to '127.0.0.1' if the
config was set to `:some-port-number`. Now it uses the BindAddr
if available. Also, if the `port` option is set to just a port`
number (e.g. '1234'), attempt to parse the port number by itself
to allow statically configured ports to work, even when no host is
specified.
In addition to the API changing, consul.Syncer can now be signaled
to shutdown via the Shutdown() method, which will call the Run()'ing
sync task to exit gracefully.
While breaking the API within this PR, break out the individual
arguments to RefreshServerLists. The servers parameter is reusing
`structs.NodeServerInfo` for the time being, but this can be revisited
if the needs of the strucutre diverge in the future.
With an over abundance of caution, preevnt future copy/pasta by
using the right locks when bootstrapping a Client. Strictly speaking
this is not necessary, but it makes explicit the locking semantics
and guards against future concurrent or parallel initialization.
When an agent is running a server, the list of servers includes the
Raft peers. When the agent is running a client (which is always the
case?), include a list of the servers found in the Client's RpcProxy.
Dedupe and provide a unique list back to the caller.
Change the unit test to only test if the consul link exists, not the
value of the link. The old test was hostname specific and therefore
would always be different based on the environment running the tests.
Reduce future confusion by introducing a minor version that is gossiped out
via the `mvn` Serf tag (Minor Version Number, `vsn` is already being used for
to communicate `Major Version Number`).
Background: hashicorp/consul/issues/1346#issuecomment-151663152
