PR#188: qcow2: Pick random port in range - standard-test-roles

standard-test-roles

#188 qcow2: Pick random port in range

Closed 5 years ago by walters. Opened 5 years ago by walters.

walters/standard-test-roles bind-random into master

Colin Walters • 5 years ago

f50bf33

file modified

+3 -1

		`@@ -8,6 +8,7 @@`
		`import shlex`
		`import signal`
		`import multiprocessing`
		`+ import random`
		`import socket`
		`import subprocess`
		`import sys`
		`@@ -105,7 +106,8 @@`


		`def start_qemu(image, cloudinit, log, portrange=(2222, 5555)):`
		`- for port in range(*portrange):`
		`+ for tries in range(10):`
		`+ port = random.randint(*portrange)`
		`sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)`
		`sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)`
		`try:`

walters commented 5 years ago

I'm working changing rpm-ostree to spawn VMs in parallel, and
currently this races because we release the socket, then start
qemu.

I have a plan for a reliable fix, but even with that let's use a random port
since it makes collissions a lot less likely.

walters commented 5 years ago

On the reliable fix; what I was thinking is something like:

env TEST_INVENTORY_QCOW2_LOCK=/tmp/test-rpm-ostree.XXXXXX/qcow2-lock then inside the code we use flock() around the launching of qemu. Basically callers can provide a file to use as a lock.

The much better fix of course is to be able to pass the socket FD down to qemu, but would require patching it and then version detection, etc.

astepano commented 5 years ago

Hi, could you please explain what do you mean under: rpm-ostree to spawn VMs in parallel ?
rpm-ostree is AtomicHost package manager, as I know. It has nothing with spawning VMs.

walters commented 5 years ago

I mean the test suite.