tailscale/tstest/integration
Christine Dodrill 6b234323a0
tstest/integration/vms: fix flake when testing (#2145)
Occasionally the test framework would fail with a timeout due to a
virtual machine not phoning home in time. This seems to be happen
whenever qemu can't bind the VNC or SSH ports for a virtual machine.
This was fixed by taking the following actions:

1. Don't listen on VNC unless the `-use-vnc` flag is passed, this
   removes the need to listen on VNC at all in most cases. The option to
   use VNC is still left in for debugging virtual machines, but removing
   this makes it easier to deal with (VNC uses this odd system of
   "displays" that are mapped to ports above 5900, and qemu doesn't
   offer a decent way to use a normal port number, so we just disable
   VNC by default as a compromise).
2. Use a (hopefully) inactive port for SSH. In an ideal world I'd just
   have the VM's SSH port be exposed via a Unix socket, however the QEMU
   documentation doesn't really say if you can do this or not. While I
   do more research, this stopgap will have to make do.
3. Strictly tie more VM resource lifetimes to the tests themselves.
   Previously the disk image layers for virtual machines were only
   cleaned up at the end of the test and existed in the parent
   test-scoped temporary folder. This can make your tmpfs run out of
   space, which is not ideal. This should minimize the use of temporary
   storage as much as I know how to.
4. Strictly tie the qemu process lifetime to the lifetime of the test
   using testing.T#Cleanup. Previously it used a defer statement to
   clean up the qemu process, however if the tests timed out this defer
   was not run. This left around an orphaned qemu process that had to be
   killed manually. This change ensures that all qemu processes exit
   when their relevant tests finish.

Signed-off-by: Christine Dodrill <xe@tailscale.com>
2021-06-25 14:45:12 -04:00
..
testcontrol tstest/integration: fix race flake 2021-06-18 10:10:23 -07:00
vms tstest/integration/vms: fix flake when testing (#2145) 2021-06-25 14:45:12 -04:00
integration_test.go tstest/integration: fix a race 2021-06-22 10:24:13 -07:00
integration.go tstest/integration/vms: copy locally built binaries (#2006) 2021-05-31 11:35:01 -04:00