[tahoe-lafs-trac-stream] [Tahoe-LAFS] #2491: synchronous node startup

[Tahoe-LAFS]

#2491: synchronous node startup
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     Reporter:  dawuud   |      Owner:  daira
         Type:  defect   |     Status:  new
     Priority:  normal   |  Milestone:  undecided
    Component:  unknown  |    Version:  1.10.1
   Resolution:           |   Keywords:  tor i2p static synchronous startup
Launchpad Bug:           |
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Comment (by warner):

 More details copied from #517:

 At node-creation time (e.g. `tahoe create-node`):

 * `tahoe create-node` should allocate (or be told) a port to listen on,
 and write it into tahoe.cfg `tub.port` as a server endpoint descriptor
 string (so `tcp:12345`, or `tcp:12345:interface=127.0.0.1`).
 * it should also detect (or be told) an IP address to use in the FURL, and
 write it as `tub.location` (as a Foolscap connection hint, so
 `tcp:HOST:PORT`)

 At runtime (e.g. `tahoe start`):

 * Try to get the port number from `BASEDIR/client.port` (which must not be
 "0"). If that's empty, read tahoe.cfg `tub.port` (which might be missing,
 which means "AUTO"; we can probably reject "0" here too).
 * if our port is "AUTO" (which only happens if we have a node created
 before the above `tahoe create-node` was deployed, but which has never
 been started with `tahoe start`), then we use the utility function to
 allocate a port, and we write it into `BASEDIR/client.port`.
 * Now we know what port to listen on. Build a server endpoint descriptor
 string and pass it to `tub.listenOn()`.
 *
 * Try to get the tub location from tahoe.cfg `tub.location`.
 * If that's empty, use the synchronous non-Twisted IP-address detection
 function to get a list of IP addresses. Combine that with the port we're
 listening on (from above) to build a list of hints. Join them with commas.
 * Pass the hints into `tub.setLocation()`.
 *
 * Now call the rest of the `Node`/`Client` startup functions.

 Other code changes/accomplishments:

 * `node.Node._tub_ready_observer` and `when_tub_ready` go away
 * several `client.Client` methods stop using `when_tub_ready` (and stop
 using Deferreds): `init_introducer_client`, `init_storage`, `init_control,
 `init_helper`, `init_key_gen`.
 * in particular, we call `tub.setLocation()` *before* calling any of those
 init methods, so they can safely use `tub.registerReference`

 Other tasks necessary to make this work:

 * move the controlport and logport to separate Tubs, with a separate
 (ephemeral) key, listening on a runtime-allocated port, and 127.0.0.1
 * consider adding a config knob to override this: to set a stable port and
 key, so you can copy the `logport.furl` to a separate machine and use
 `flogtool tail` after a reboot.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2491#comment:3>
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