[tahoe-lafs-trac-stream] [Tahoe-LAFS] #2816: make sure tub.location and tub.port can be empty

[Tahoe-LAFS]

#2816: make sure tub.location and tub.port can be empty
--------------------------------+--------------------
     Reporter:  warner          |      Owner:  warner
         Type:  task            |     Status:  new
     Priority:  normal          |  Milestone:  1.12.0
    Component:  code-nodeadmin  |    Version:  1.11.0
   Resolution:                  |   Keywords:
Launchpad Bug:                  |
--------------------------------+--------------------

Comment (by warner):

 Current ([2d8a1e865], 29-Aug-2016, pre-1.12) behavior of `tub.port` is:

 * `tub.port = STRING`:
   * if string is all-numeric PORT, use `tcp:PORT`
   * else the string must be an endpoint like `tcp:HOST` or
 `tcp:HOST:interface=127.0.0.1`
 * `#tub.port =` (omitted entirely):
   * if `NODEDIR/tub.port` is present, treat as PORT or endpoint string
   * if not present, allocate a TCP port, write `tcp:PORT` to
 `NODEDIR/tub.port` for future use
 * `tub.port =` (empty value): same as `tub.port =` (empty value)

 Current `tahoe create-client`/`create-node` will write `#tub.port =` into
 `tahoe.cfg`, which means for most nodes that haven't been explicitly
 configured (probably to a deliberate port number), the key is missing
 entirely.

 The proposed change is to treat `tub.port =` (empty value) as instructions
 to not start up a Listener. While this is a change in behavior, I don't
 think many client nodes are likely to be configured with an empty string.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2816#comment:2>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage