kt: Add vm command

This will create a vm for a kernel workspace created earlier with kt checkout.
If the vm does not exists, it will create it.

It includes options to get console access, to destroy the vm and list
the running vms.

The most relevant one is the --test option that builds the kernel
from kernel-src-tree of the matching kernel workspace, boots it and then
kselftests are run.

TODOs:
1. autocompletion work fine, except if --destroy is used.
Ideally when --destroy is used, only the running vms should be shown.
For now, please check the existing vms with kt vm --list-all
and then run kt vm --destroy <kernel_workspace>
2. The implementation replies a lot of waiting for the vm to boot up,
install depedencies etc. Hence the time.sleep() calls. It would be improved
in the future.

IMPORTANT:
The vm instance needs to have access to this repo because the scripts
for building the kernel, running the kselftests and installing depedencies.
We share <config.kernels_dir> with the vm, so please make sure this repo
is there. That's what the implementation assumes.

Note: Make sure your user is part of the libvirt group, otherwise
you will need to type the root password multiple times, because kt
calls virsh multiple times before getting access to a vm: for checking if
it exists etc.

Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com>

Author: roxanan1996

bin/kt

@@ -8,6 +8,7 @@ from kt.commands.checkout.command import checkout
 from kt.commands.git_push.command import git_push
 from kt.commands.list_kernels.command import list_kernels
 from kt.commands.setup.command import setup
+from kt.commands.vm.command import vm
 
 epilog = """
 Base of all tooling used for kernel development.
@@ -28,6 +29,7 @@ def main():
     cli.add_command(setup)
     cli.add_command(checkout)
     cli.add_command(git_push)
+    cli.add_command(vm)
     cli()
 
 

kt/KT.md

@@ -227,3 +227,71 @@ This is the working directory for this kernel:
 
     This representes branch `{<user>}/ciqlts9_4:origin/ciqlts9_4`
     The source repo is ~/ciq/kernel-src-tree
+
+### kt vm
+
+It spins up a virtual machine for the corresponding kernel.
+If the virtual machine does not exist, it gets created.
+
+First, the vm image base (source) is downloaded if it does not exist
+in <config.images_source_dir>.
+To spin up the machine, a copy of this qcow2 image is put in
+<config.images_dir/<kernel>. Even if kernels may share the same image base,
+they will have their own configuration and image.
+cloud-init.yaml configuration is taken from kt/data and modified accordingly
+for each user and then put in the same folder.
+
+Make sure your user is part of the libvirt group, otherwise you would need
+to type your root password multiple times when getting access to the vm:
+```
+$ sudo usermod -a -G libvirt $(whoami)
+```
+
+#### Example:
+```
+$ kt vm lts9_4
+```
+
+For this configuration
+```
+{
+    "base_path": "~/ciq",
+    "kernels_dir": "~/ciq/kernels",
+    "images_source_dir": "~/ciq/default_test_images",
+    "images_dir": "~/ciq/tmp/virt-images",
+    "ssh_key": "~/.ssh/id_ed25519_generic.pub",
+}
+```
+
+Here is the qcow2 vm image used as source for other vms as well:
+
+```
+~/ciq/default_test_images/Rocky-9-GenericCloud-Base.latest.x86_64.qcow2
+```
+
+And here are the actual vm configuration and image files:
+```
+ciq/tmp/virt-images/lts-9.4/cloud-init.yaml
+ciq/tmp/virt-images/lts-9.4/lts-9.4.qcow2
+```
+
+The cloud-init.yaml file is adapted from kt/data/cloud-init.yaml base file.
+
+`virt-install` command is then used to create the vm.
+
+If `--console` option is used, then `virsh --connect qemu://system console lts9-4`
+is run (indirectly).
+
+
+If `--test` option is used, then we connect to the vm via ssh and run
+
+```
+<config.base_path>/kernel-src-tree-tools/kernel-build.sh -n
+```
+
+reboot
+and then
+
+```
+<config.base_path>/kernel-src-tree-tools/kernel-kselftest.sh
+```

kt/commands/vm/command.py

@@ -0,0 +1,62 @@
+import click
+
+from kt.commands.vm.impl import main
+from kt.ktlib.shell_completion import ShellCompletion
+
+epilog = """
+It spins up a virtual machine for the corresponding kernel.
+
+If the virtual machine does not exist, it gets created.
+
+First, the vm image base (source) is downloaded if it does not exist
+in <config.images_source_dir>.
+
+To spin up the machine, a copy of this qcow2 image is put in
+<config.images_dir/<kernel>. Even if kernels may share the same image base,
+they will have their own configuration and image.
+cloud-init.yaml configuration is taken from kt/data and modified accordingly
+for each user and then put in the same folder.
+
+Examples:
+
+\b
+$ kt vm lts9_4
+\b
+$ kt vm lts9_4 --console
+\b
+$ kt vm lts9_4 -c
+\b
+$ kt vm lts9_4 --destroy
+\b
+$ kt vm lts9_4 -c --override
+
+"""
+
+
+@click.command(epilog=epilog)
+@click.option(
+    "-c",
+    "--console",
+    is_flag=True,
+    help="It connects to the console of the vm",
+)
+@click.option(
+    "-d",
+    "--destroy",
+    is_flag=True,
+    help="It destroys the vm",
+)
+@click.option(
+    "--override",
+    is_flag=True,
+    help="It destroys the vm if it exists and creates a new one",
+)
+@click.option(
+    "--list-all",
+    is_flag=True,
+    help="Lists existings vms",
+)
+@click.option("--test", is_flag=True, help="Build the kernel and run kselftests")
+@click.argument("kernel_workspace", required=False, shell_complete=ShellCompletion.show_kernel_workspaces)
+def vm(kernel_workspace, console, destroy, override, list_all, test):
+    main(name=kernel_workspace, console=console, destroy=destroy, override=override, list_all=list_all, test=test)