pmap: Let brick choose it's own port

[prashanthpai]

With glusterfs change https://review.gluster.org/21249, glusterd2 can choose
to not to pass an explicit port when starting brick process. The brick process
shall choose a free port provided by the kernel and reports this port number
to glusterd2 via a SIGN IN request.

The pmap package will no longer manage and track available free ports. This
means that running multiple glusterd2 instances on same machine (e2e) are
now not prone to races in finding a free port to assign to a brick.

Fixes #924
Signed-off-by: Prashanth Pai ppai@redhat.com

[prashanthpai]

Sample output:

[ppai@gd2-1 glusterd2]$ glustercli volume status test
Volume : test
+--------------------------------------+-----------+---------------------+--------+-------+-------+
|               BRICK ID               |   HOST    |        PATH         | ONLINE | PORT  |  PID  |
+--------------------------------------+-----------+---------------------+--------+-------+-------+
| bedf6c5c-859d-4f52-9b68-523e0f4b9cdd | 127.0.0.1 | /export/brick1/data | true   | 46501 | 29081 |
| 28c10e8e-f8c9-4131-a4a1-b36dcfb1e6eb | 127.0.0.1 | /export/brick2/data | true   | 40467 | 29103 |
| b1664b0e-9abf-4d8c-8ef6-3bf0ba9fb168 | 127.0.0.1 | /export/brick3/data | true   | 44037 | 29125 |
| 867d1cc5-743e-46d9-b3ce-166d612bcc2f | 127.0.0.1 | /export/brick4/data | true   | 45479 | 29147 |
+--------------------------------------+-----------+---------------------+--------+-------+-------+

[ppai@gd2-1 glusterd2]$ glustercli volume stop test
Volume test stopped successfully
[ppai@gd2-1 glusterd2]$ glustercli volume status test
Volume : test
+--------------------------------------+-----------+---------------------+--------+------+-----+
|               BRICK ID               |   HOST    |        PATH         | ONLINE | PORT | PID |
+--------------------------------------+-----------+---------------------+--------+------+-----+
| 28c10e8e-f8c9-4131-a4a1-b36dcfb1e6eb | 127.0.0.1 | /export/brick2/data | false  |    0 |   0 |
| b1664b0e-9abf-4d8c-8ef6-3bf0ba9fb168 | 127.0.0.1 | /export/brick3/data | false  |    0 |   0 |
| 867d1cc5-743e-46d9-b3ce-166d612bcc2f | 127.0.0.1 | /export/brick4/data | false  |    0 |   0 |
| bedf6c5c-859d-4f52-9b68-523e0f4b9cdd | 127.0.0.1 | /export/brick1/data | false  |    0 |   0 |
+--------------------------------------+-----------+---------------------+--------+------+-----+

[ppai@gd2-1 glusterd2]$ glustercli volume start test
Volume test started successfully


[ppai@gd2-1 glusterd2]$ glustercli volume status test
Volume : test
+--------------------------------------+-----------+---------------------+--------+-------+-------+
|               BRICK ID               |   HOST    |        PATH         | ONLINE | PORT  |  PID  |
+--------------------------------------+-----------+---------------------+--------+-------+-------+
| bedf6c5c-859d-4f52-9b68-523e0f4b9cdd | 127.0.0.1 | /export/brick1/data | true   | 35607 | 29190 |
| 28c10e8e-f8c9-4131-a4a1-b36dcfb1e6eb | 127.0.0.1 | /export/brick2/data | true   | 38785 | 29212 |
| b1664b0e-9abf-4d8c-8ef6-3bf0ba9fb168 | 127.0.0.1 | /export/brick3/data | true   | 43205 | 29234 |
| 867d1cc5-743e-46d9-b3ce-166d612bcc2f | 127.0.0.1 | /export/brick4/data | true   | 33987 | 29256 |
+--------------------------------------+-----------+---------------------+--------+-------+-------+

[ppai@gd2-1 glusterd2]$ curl -s -X GET http://127.0.0.1:24007/statedump | grep pmap
"pmap": {"ports":{"33987":{"/export/brick4/data":{}},"35607":{"/export/brick1/data":{}},"38785":{"/export/brick2/data":{}},"43205":{"/export/brick3/data":{}}}},

[amarts]

How are you sure about this? Should this be 1024?

[prashanthpai]

This is arbitrary. It can be anything in the range 1024 to 65535.

[amarts]

Other than the tests where you set basePort as 49152, everything else LGTM

[aravindavk]

LGTM