tailscale/tstest/integration/vms
Christine Dodrill 798b0da470
tstest/integration/vms: codegen for top level tests (#2441)
This moves the distribution definitions into a maintainable hujson file
instead of just existing as constants in `distros.go`. Comments are
maintained from the inline definitions.

This uses jennifer[1] for hygenic source tree creation. This allows us
to generate a unique top-level test for each VM run. This should
hopefully help make the output of `go test` easier to read.

This also separates each test out into its own top-level test so that we
can better track the time that each distro takes. I really wish there
was a way to have the `test_codegen.go` file _always_ run as a part of
the compile process instead of having to rely on people remembering to
run `go generate`, but I am limited by my tools.

This will let us remove the `-distro-regex` flag and use `go test -run`
to pick which distros are run.

Signed-off-by: Christine Dodrill <xe@tailscale.com>
2021-07-16 15:25:16 -04:00
..
gen tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
derive_bindhost_test.go tstest/integration/vms: split up test framework into files (#2396) 2021-07-13 13:45:09 -04:00
distros_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
distros.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
distros.hujson tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
doc.go tstest/integration: add experimental integration test (#1966) 2021-05-26 14:10:10 -04:00
harness_test.go tstest/integration/vms: use one testcontrol instance per VM (#2437) 2021-07-16 11:53:12 -04:00
nixos_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
opensuse_leap_15_1_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
README.md tstest/integration/vms: download images from s3 (#2035) 2021-06-08 12:47:24 -04:00
regex_flag_test.go tstest/integration/vms: regex-match distros using a flag (#2021) 2021-05-31 13:23:38 -04:00
regex_flag.go tstest/integration/vms: regex-match distros using a flag (#2021) 2021-05-31 13:23:38 -04:00
runner.nix tstest/integration/vms: build and run NixOS (#2190) 2021-06-28 09:45:45 -04:00
top_level_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
udp_tester.go Revert "Revert "tstest/integration/vms: end-to-end UDP test (#2361)" (#2364)" (#2365) 2021-07-12 14:53:16 -04:00
vm_setup_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00
vms_steps_test.go tstest/integration/vms: use one testcontrol instance per VM (#2437) 2021-07-16 11:53:12 -04:00
vms_test.go tstest/integration/vms: codegen for top level tests (#2441) 2021-07-16 15:25:16 -04:00

End-to-End VM-based Integration Testing

This test spins up a bunch of common linux distributions and then tries to get them to connect to a testcontrol server.

Running

This test currently only runs on Linux.

This test depends on the following command line tools:

This test also requires the following:

  • about 10 GB of temporary storage
  • about 10 GB of cached VM images
  • at least 4 GB of ram for virtual machines
  • hardware virtualization support (KVM) enabled in the BIOS
  • the kvm module to be loaded (modprobe kvm)
  • the user running these tests must have access to /dev/kvm (being in the kvm group should suffice)

This optionally requires an AWS profile to be configured at the default path. The S3 bucket is set so that the requester pays. Please keep this in mind when running these tests on your machine. If you are uncomfortable with the cost from downloading from S3, you should pass the -no-s3 flag to disable downloads from S3. However keep in mind that some distributions do not use stable URLs for each individual image artifact, so there may be spurious test failures as a result.

If you are using Nix, you can run all of the tests with the correct command line tools using this command:

$ nix-shell -p openssh -p go -p qemu -p cdrkit --run "go test . --run-vm-tests --v --timeout 30m"

Keep the timeout high for the first run, especially if you are not downloading VM images from S3. The mirrors we pull images from have download rate limits and will take a while to download.

Because of the hardware requirements of this test, this test will not run without the --run-vm-tests flag set.

Other Fun Flags

This test's behavior is customized with command line flags.

Don't Download Images From S3

If you pass the -no-s3 flag to go test, the S3 step will be skipped in favor of downloading the images directly from upstream sources, which may cause the test to fail in odd places.

Distribution Picking

This test runs on a large number of distributions. By default it tries to run everything, which may or may not be ideal for you. If you only want to test a subset of distributions, you can use the --distro-regex flag to match a subset of distributions using a regular expression such as like this:

$ go test -run-vm-tests -distro-regex centos

This would run all tests on all versions of CentOS.

$ go test -run-vm-tests -distro-regex '(debian|ubuntu)'

This would run all tests on all versions of Debian and Ubuntu.

Ram Limiting

This test uses a lot of memory. In order to avoid making machines run out of memory running this test, a semaphore is used to limit how many megabytes of ram are being used at once. By default this semaphore is set to 4096 MB of ram (about 4 gigabytes). You can customize this with the --ram-limit flag:

$ go test --run-vm-tests --ram-limit 2048
$ go test --run-vm-tests --ram-limit 65536

The first example will set the limit to 2048 MB of ram (about 2 gigabytes). The second example will set the limit to 65536 MB of ram (about 65 gigabytes). Please be careful with this flag, improper usage of it is known to cause the Linux out-of-memory killer to engage. Try to keep it within 50-75% of your machine's available ram (there is some overhead involved with the virtualization) to be on the safe side.