NixOS VM tests: Difference between revisions
imported>Teto random notes as I was trying to reuse the nixos test infra (especially the VDE logic) within nixos-shell |
imported>Teto m cleanup |
||
| Line 7: | Line 7: | ||
The driver (of the form /nix/store/668bqxvsv6rn9hy8n4nmaps9ma2i5k4r-nixos-test-driver-<TESTNAME>) will launch the different vms passed as arguments. | 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 ? | == How to debug tests ? == | ||
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`. | ||
Revision as of 10:04, 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`.