From 126ce87b0c7e526c8d1f2eccd868e89ef61deab3 Mon Sep 17 00:00:00 2001 From: Jamie McClymont Date: Thu, 3 Mar 2022 19:01:44 +1300 Subject: [PATCH] nixos/tests: fix flaky cntr test The cntr sometimes hangs until the 10-hour hydra limit. This behaviour appears to be an edge-case related to the type of TTY in which the cntr command runs during test execution. We can work around this by running the command as a background job. I additionally added a wait_for_open_port to fix nondeterministic test failures I observed after fixing the hanging issue. --- nixos/tests/cntr.nix | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/nixos/tests/cntr.nix b/nixos/tests/cntr.nix index 668470756209..e4e13545b876 100644 --- a/nixos/tests/cntr.nix +++ b/nixos/tests/cntr.nix @@ -28,10 +28,16 @@ let testScript = '' start_all() ${backend}.wait_for_unit("${backend}-nginx.service") - result = ${backend}.wait_until_succeeds( - "cntr attach -t ${backend} nginx sh -- -c 'curl localhost | grep Hello'" + ${backend}.wait_for_open_port(8181) + # For some reason, the cntr command hangs when run without the &. + # As such, we have to do some messy things to ensure we check the exitcode and output in a race-condition-safe manner + ${backend}.execute( + "(cntr attach -t ${backend} nginx sh -- -c 'curl localhost | grep Hello' > /tmp/result; echo $? > /tmp/exitcode; touch /tmp/done) &" ) - assert "Hello" in result + + ${backend}.wait_for_file("/tmp/done") + assert "0" == ${backend}.succeed("cat /tmp/exitcode").strip(), "non-zero exit code" + assert "Hello" in ${backend}.succeed("cat /tmp/result"), "no greeting in output" ''; }; @@ -54,7 +60,13 @@ let testScript = '' machine.start() machine.wait_for_unit("container@test.service") - machine.succeed("cntr attach test sh -- -c 'ping -c5 172.16.0.1'") + # I haven't observed the same hanging behaviour in this version as in the OCI version which necessetates this messy invocation, but it's probably better to be safe than sorry and use it here as well + machine.execute( + "(cntr attach test sh -- -c 'ping -c5 172.16.0.1'; echo $? > /tmp/exitcode; touch /tmp/done) &" + ) + + machine.wait_for_file("/tmp/done") + assert "0" == machine.succeed("cat /tmp/exitcode").strip(), "non-zero exit code" ''; }; in {