Commit 126ce87b authored by Jamie McClymont's avatar Jamie McClymont
Browse files

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.
parent 2f7ef979

nixos/tests/cntr.nix

+16 −4
Original line number Diff line number Diff line
@@ -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 {