Adds a flag --rpc_use_loopback that causes two differences
in behaviour when enabled:
1. KRPC will listen on all interfaces, i.e. bind the socket
to INADDR_ANY.
2. KRPC RPCs to --hostname are sent to 127.0.0.1 instead of
the IP (maybe external) that --hostname resolves to.
There is no change in default behaviour, except in containers,
where this flag is enabled by default.
Testing:
* Added a custom cluster test, which runs in exhaustive,
as a sanity test for the behaviour of the flag.
Change-Id: I9dbd477769ed49c05e624f06da4e51afaaf1670d
Reviewed-on: http://gerrit.cloudera.org:8080/13592
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
