It's more precise to use dig rather than ping. The stock ubuntu image
doesn't come with dig (in package dnsutils), but luckily Aanand made
an image which is exactly ubuntu+dnsutils.
1) log more lifecycle events
- acceptance
- handshake completion
- added & removed (from our connection map)
The latter is a bit verbose but may help us track down the cause for
going to introduce here, then this would fall in the 'debug' category.
2) better error logging
- log error as part of "shutting down" log event rather than separately
- indicate "blocked UDP connectivity" as a possible cause when
getting a timeout on a not-fully-established connection.
The rationale for the latter is that inbound connections get
marked as established when first receiving a heartbeat frame over
UDP, which are the only frames that get transmitted prior to the
connection being fully established. Note that outbound
connections get marked as established when receiving the
ConnectionEstablished message over TCP, which is sent by the peer
when it first receives a heartbeat. See #342.
Closes#340.
conn.shutdown was only set/accessed in handleShutdown, which in turn
is only called on termination of queryLoop and hence multiple
invocations are impossible.
* Put prefixes (including msg IDs) in front of log messages to
distinguish them
* Failed lookups get logged under Info as per issue #311
* More accurate messages as per issue #311
So as not to pollute command-line flags with test.* options.
It appears that importing "testing" (from stdlib) will add flags. To
avoid this, we need code to not depend on testing. But, since
testing_utils was previously in the same package as the rest of the
code, it dragged testing in.
Renaming testing_util.go to e.g., util_for_test.go might be enough to
avoid it being compiled with the regular code. We may want it to be
available to tests for other packages -- after all it is utilities for
testing -- so it goes in its own package.
NB I removed free variables from the LookupFunc implementations, to
avoid confusion between `s` the receiver and the closed-over `s`.
Also corrected a mistake in the write error log message.
Matthias Radestock