NixOS VM tests: Difference between revisions
imported>Teto m cleanup |
imported>Teto adding clever's trick to fix some failing tests |
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You can run the tests interactively as described in nixos manual. | You can run the tests interactively as described in nixos manual. | ||
When you run `nix-build ./nixos/tests/login.nix`, the resulting output gives you a summary of the results, but to gain access to the VM, you can run `nix repl ./nixos/tests/login.nix` and see the ran VM via `driver.outPath`. | When you run `nix-build ./nixos/tests/login.nix`, the resulting output gives you a summary of the results, but to gain access to the VM, you can run `nix repl ./nixos/tests/login.nix` and see the ran VM via `driver.outPath`. | ||
== I don't see any prompt ? (qemu window pitch black) == | |||
Check the output for `malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "\x{0}\x{0}\x{0}\x{0}...") at /nix/store/1hkp2n6hz3ybf2rvkjkwrzgbjkrrakzl-update-users-groups.pl line 11`. | |||
You should purge the state present in rm -rf /tmp/vm-state-<VM_NAME> | |||
Revision as of 10:41, 8 July 2019
The test infrastructure entry point is nixos/lib/testing.nix. The test infra relies on the qemu build-vm code to generate virtual machines.
It will generate a test driver (a wrapper of nixos/lib/test-driver/test-driver.pl) in charge of creating the network. It will start one vde-switch and its associated socket per vlan (defined in virtualisation.vlans). IPs are assigned declaratively according to the number of vlan via the function `assignIPAddresses`.
The driver (of the form /nix/store/668bqxvsv6rn9hy8n4nmaps9ma2i5k4r-nixos-test-driver-<TESTNAME>) will launch the different vms passed as arguments. The wrapper `bin/nixos-run-vms` is in charge to start the driver with the correct VM script as arguments.
Once the driver is loaded, depending on the environment variables `tests` it will run in an interactive mode or run some perl code (`testScript`). In interactive mode, you can run `startAll` followed by `joinAll` to start and keep the VM alive
How to debug tests ?
You can run the tests interactively as described in nixos manual. When you run `nix-build ./nixos/tests/login.nix`, the resulting output gives you a summary of the results, but to gain access to the VM, you can run `nix repl ./nixos/tests/login.nix` and see the ran VM via `driver.outPath`.
I don't see any prompt ? (qemu window pitch black)
Check the output for `malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "\x{0}\x{0}\x{0}\x{0}...") at /nix/store/1hkp2n6hz3ybf2rvkjkwrzgbjkrrakzl-update-users-groups.pl line 11`. You should purge the state present in rm -rf /tmp/vm-state-<VM_NAME>