Kill singleuser test servers to reduce k3s resource usage

[manics]

Closes #1754

We build and launch several servers, but we don't shut them down.

binderhub/binderhub/tests/test_build.py

Lines 52 to 96 in af81d7f

	async def test_build(app, needs_build, needs_launch, always_build, slug, pytestconfig):
	"""
	Test build a repo that is very quick and easy to build.
	"""
	# can't use mark.github_api since only some tests here use GitHub
	if slug.startswith("gh/") and "not github_api" in pytestconfig.getoption(
	"markexpr"
	):
	pytest.skip("Skipping GitHub API test")
	build_url = f"{app.url}/build/{slug}"
	r = await async_requests.get(build_url, stream=True)
	r.raise_for_status()
	events = []
	launch_events = 0
	async for line in async_requests.iter_lines(r):
	line = line.decode("utf8", "replace")
	if line.startswith("data:"):
	event = json.loads(line.split(":", 1)[1])
	events.append(event)
	assert "message" in event
	sys.stdout.write(f"{event.get('phase', '')}: {event['message']}")
	# this is the signal that everything is ready, pod is launched
	# and server is up inside the pod. Break out of the loop now
	# because BinderHub keeps the connection open for many seconds
	# after to avoid "reconnects" from slow clients
	if event.get("phase") == "ready":
	r.close()
	break
	if event.get("phase") == "launching" and not event["message"].startswith(
	("Launching server...", "Launch attempt ")
	):
	# skip standard launching events of builder
	# we are interested in launching events from spawner
	launch_events += 1
	assert launch_events > 0
	final = events[-1]
	assert "phase" in final
	assert final["phase"] == "ready"
	assert "url" in final
	assert "token" in final
	print(final["url"])
	r = await async_requests.get(url_concat(final["url"], {"token": final["token"]}))
	r.raise_for_status()
	assert r.url.startswith(final["url"])

[consideRatio]

Wieeeee thanks for resolving this @manics!!!!!!!!!