Not entirely sure when it got broken this time, but when creating a VM
network with `nixos-build-vms(8)`, there are should be the following scripts:
* `$out/bin/nixos-test-driver` which drops into an interactive shell to
interactively perform test steps.
* `$out/bin/nixos-run-vms` which non-interactively starts the VMs from
the network so that one can manually play around in the VM.
The latter also starts an interactive shell for a while now which means
that it does the exact same thing as `nixos-test-driver` which is not
its purpose.
This commit encapsulates the involved domain into classes and
defines explicit and typed arguments where untyped dicts where used.
It preserves backwards compatibility through legacy wrappers.
This reverts commit aab534b894 & uses the
driverInteractive attribute for the test driver instead.
This has the same effect but removes the extra module in the
nixos-build-vms code.
When I test a change e.g. in the module system manually, I usually use
`nixos-build-vms(8)` which also gives me a QEMU window where I can play
around in the freshly built VM.
It seems as this has changed recently when the default package for
non-interactive VM tests using the same framework was switched to
`pkgs.qemu_test` to reduce the closure size. While this is a reasonable
decision for our CI tests, I think that you really want a QEMU window of
the VM by default when using `nixos-build-vms(8)`.
[1] bc2188b083
When trying to build a VM using `nixos-build-vms` with a configuration
that doesn't evaluate, an error "at `<unknown-file>`" is usually shown.
This happens since the `build-vms.nix` creates a VM-network of
NixOS-configurations that are attr-sets or functions and don't contain
any file information. This patch manually adds the `_file`-attribute to
tell the module-system which file contained broken configuration:
```
$ cat vm.nix
{ vm.invalid-option = 1; }
$ nixos-build-vms vm.nix
error: The option `invalid-option' defined in `/home/ma27/Projects/nixpkgs/vm.nix@node-vm' does not exist.
(use '--show-trace' to show detailed location information)
```
In 0945178b3c we decided that Perl-based
VM tests should be deprecated and will be removed between 20.03 and
20.09. So let's switch `nixos-build-vms(8)` to python as well (which is
entirely interactive, so other scripts won't break).
In my experience, the test-driver isn't used most of the time, so this
patch is mainly supposed to get rid of the (probably misleading)
deprecation warning when running `nixos-build-vms`. Apart from that, the
interface for python's test-driver is way nicer.
Previously I got the following error message:
```
error: opening file '/home/ma27/Projects/nixpkgs/nixos/modules/installer/default.nix': No such file or directory
```
Probably related to 6c68fbd4e1.
- Added a backdoor option to the interactive run-vms script. This allows me to intergrate the virtual network approach with Disnix
- Small documentation fixes
Some explanation:
The nixos-build-vms command line tool can be used to build a virtual network of a network.nix specification.
For example, a network configuration (network.nix) could look like this:
{
test1 =
{pkgs, config, ...}:
{
services.openssh.enable = true;
...
};
test2 =
{pkgs, config, ...}:
{
services.openssh.enable = true;
services.xserver.enable = true;
}
;
}
By typing the following instruction:
$ nixos-build-vms -n network.nix
a virtual network is built, which can be started by typing:
$ ./result/bin/run-vms
It is also possible to enable a backdoor. In this case *.socket files are stored in the current directory
which can be used by the end-user to invoke remote instruction on a VM in the network through a Unix
domain socket.
For example by building the network with the following instructions:
$ nixos-build-vms -n network.nix --use-backdoor
and launching the virtual network:
$ ./result/bin/run-vms
You can find two socket files in your current directory, namely: test1.socket and test2.socket.
These Unix domain sockets can be used to remotely administer the test1 and test2 machine
in the virtual network.
For example by running:
$ socat ./test1.socket stdio
ls /root
You can retrieve the contents of the /root directory of the virtual machine with identifier test1
svn path=/nixos/trunk/; revision=24410
Maximilian Bosch