Tutorial: managing bhyve virtual machines using virt-manager

The goal of this tutorial is to help you get started with virt-manager on FreeBSD for managing bhyve VMs. We’ll go through installation and basic configuration, and then set up a FreeBSD guest.

Installation

To install virt-manager, run:

# pkg install virt-manager

This will also pull in libvirt as a dependency.

Configuration

Edit /etc/rc.conf and add:

libvirtd_enable="YES"

You can validate your setup by running:

# virt-host-validate
 BHYVE: Checking for vmm module                                              : PASS
 BHYVE: Checking for if_tap module                                           : WARN (if_tap module is not loaded, networking will not work)
 BHYVE: Checking for if_bridge module                                        : PASS
 BHYVE: Checking for nmdm module                                             : PASS
#

The if_tap warning isn’t critical if it’s compiled into your kernel.

Next, adjust libvirt’s control socket permissions. Edit /usr/local/etc/libvirt/libvirtd.conf and add:

unix_sock_group = "wheel"
unix_sock_rw_perms = "0770"

The last prep step is to add a default network:

# cp /usr/local/share/examples/libvirt/networks/default.xml /usr/local/etc/libvirt/qemu/networks
# ln -s ../default.xml /usr/local/etc/libvirt/qemu/networks/autostart/default.xml

Now start libvirtd:

# service libvirtd start
Starting libvirtd.
#

And then start virt-manager:

$ virt-manager

Creating a VM

Go to "File" → "Add Connection", choose bhyve:

Click "bhyve", then open the "Virtual Networks" tab. You should see the default network listed:

Press the "Play" button to start it.

Now create a new VM: "File" → "New Virtual Machine".

Choose "Local install media" → "Forward". Then click "Browse" to select an ISO.

By default it shows /var/lib/libvirt/images, but you can pick an ISO from your home directory with "Browse Local".

Uncheck "Automatically detect from the installation media / source", search for "FreeBSD", and select "FreeBSD 14.2". (The auto-detection is buggy right now.)

The next step is CPU and memory setup — straightforward.

Then configure storage:

If everything’s correct, you’ll see the FreeBSD installer:

I’ll let you handle the installation itself. The only important bit: at the end, make sure you shut the VM down. Boot order isn’t supported yet, so you don’t want to boot from the ISO again.

Once shut down, open "View" → "Details", find "SATA CDROM 1", right-click, and choose "Remove Hardware".

Now start the VM again — you should boot straight into your new FreeBSD system:

That’s it for now. I plan to fix a few rough edges to make things smoother. In the meantime, feel free to send me suggestions or bug reports at novel@FreeBSD.org, or open a PR in FreeBSD Bugzilla.

CI for libvirt/bhyve on FreeBSD

This year, I was lucky to be sponsored by the FreeBSD Foundation to improve libvirt's FreeBSD integration. One of the areas of focus was enabling CI. Actually, I had wanted to have some form of CI for a while, as manually testing things is quite time-consuming. Quite often, I don’t have enough time to test RC releases, so sometimes the releases ship with issues on FreeBSD. I knew about the libvirt TCK project (TCK stands for "Technology Compatibility Kit"), but I wasn’t sure whether it would be easier to implement my own testing routine or port the existing one to run on FreeBSD.

When I started this project, I decided to re-evaluate libvirt-tck, because it makes much more sense to re-use the existing tests—even if the initial porting requires more effort—than to implement everything from scratch.

The first steps of getting libvirt-tck to run were a bit tricky, because it starts with image generation using virt-builder. The virt-builder tool is part of libguestfs, which has not been ported to FreeBSD. I imagine porting libguestfs is not a trivial task, and it has been listed on the FreeBSD Wanted Ports list for a while. I didn’t want to dig into porting libguestfs, so I tried a few different workarounds—for example, creating a wrapper script to run virt-builder on a Linux host via SSH, then copying the resulting image with scp or using a shared partition. I also tried running it with Linuxulator. These methods had mixed success, but I later realized that once the image is generated, it can be reused for subsequent runs. It’s not ideal, but it works for now. With the image available, I could move on to the next phase: adjusting the tests themselves. This mainly involved handling cases where bhyve doesn’t support certain features and making a few patches to libvirt’s driver.

Some of that work was not very exciting, but it did result in new features being implemented, such as virtio-rnd support. Sometimes it was simply easier to add a missing feature than to handle its absence. It took a few merge requests to libvirt-tck and a few libvirt releases to get things working, but eventually the main set of tests I wanted to run worked fine. These tests include:

• domain
• networks
• storage

The main tests I wanted to run were successful: domain, networks, and storage. However, there are still a few test groups that I don’t run, either because they aren’t relevant or aren’t supported on FreeBSD:

• hooks
• nwfilter
• qemu
• selinux

I think I need to take a closer look at the hooks tests. In the future, libvirt on FreeBSD might gain nwfilter support, so those tests could become relevant, but it’s unlikely to happen soon. I had no plans to support the qemu driver on FreeBSD (why, when bhyve is available?), but with the vmm(4) accelerator support for QEMU, it might become useful. And selinux is obviously not applicable.

The final part was Jenkins configuration. Frankly, I don’t have much experience configuring Jenkins, though I do use it fairly often at work.

My "pipeline" (which is not really a pipeline in the strict sense) consists of two steps:

• Build a "-devel" version of the libvirt port (pointing to a Git repository) using poudriere(8), and publish the results to a package repo.
• Spin up a BastilleBSD container, install the libvirt packages from the previous step, check out libvirt-tck from Git, run the tests, and publish the results.

I use the "Job DSL" plugin to store job configuration, which is available in the Git repo. While the setup works, there are still several areas I’d like to improve:

• I’d like to figure out how to build an arbitrary Git revision of the port, without updating DISTVERSION in Makefile or the checksums in distinfo. Probably it would be easier to just build libvirt manually. That would also simplify the pipeline.
• I need to see if I can store not only job configurations in plain text, but also a complete Jenkins configuration, so I don’t have to manually install plugins and so on.
• I definitely need to script the test image creation process.

urbandict 0.6.1

I've released a new version of urbandict, a Python client and a CLI tool for https://urbandictionary.com. Version 0.6.1 includes support for word categories, that, apparently, was recently added by urbandictionary.

You can upgrade it using pip install --upgrade urbandict or grab source code on github.

Configuring OpenBGPD to announce VM's virtual networks

We use BGP quite heavily at work, and even though I'm not interacting with that directly, it feels like it's something very useful to learn at least on some basic level. The most effective and fun way of learning technology is finding some practical application, so I decided to see if it could help to improve networking management for my Virtual Machines.

My setup is fairly simple: I have a host that runs bhyve VMs and I have a desktop system from where I ssh to VMs, both hosts run FreeBSD. All VMs are connected to each other through a bridge and have a common network 10.0.1/24. The point of this exercise is to be able to ssh to these VMs from desktop without adding static routes and without adding vmhost's external interfaces to the VMs bridge.

I've installed openbgpd on both hosts and configured it like this:

vmhost: /usr/local/etc/bgpd.conf

AS 65002
router-id 192.168.87.48
fib-update no

network 10.0.1.1/24

neighbor 192.168.87.41 {
    descr "desktop"
    remote-as 65001
}

Here, router-id is set vmhost's IP address in my home network (192.168.87/24), fib-update no is set to forbid routing table update, which I initially set for testing, but keeping it as vmhost is not supposed to learn new routes from desktop anyway. network announces my VMs network and neighbor describes my desktop box.

Now the desktop box:

desktop: /usr/local/etc/bgpd.conf

AS 65001
router-id 192.168.87.41
fib-update yes

neighbor 192.168.87.48 {                                                                                                                                                                                           
        descr "vmhost"                                                                                                                                                                                             
        remote-as 65002                                                                                                                                                                                            
}

It's pretty similar to vmhost's bgpd.conf, but no networks are announced here, and fib-update is set to yes because the whole point is to get VM routes added.

Both hosts have to have the openbgpd service enabled:

/etc/rc.conf.local

openbgpd_enable="YES"

Now start the service (or wait until next reboot) using service openbgpd start and check if neighbors are there:

vmhost: bgpctl show summary

$ bgpctl show summary                                                                                                                                                                    
Neighbor                   AS    MsgRcvd    MsgSent  OutQ Up/Down  State/PrfRcvd                                                                                                                                   
desktop                 65001       1089       1090     0 09:03:17      0                                                                                                                                          
$

desktop: bgpctl show summary

$ bgpctl show summary
Neighbor                   AS    MsgRcvd    MsgSent  OutQ Up/Down  State/PrfRcvd
vmhost                  65002       1507       1502     0 09:04:58      1
$

Get some detailed information about the neighbor:

desktop: bgpctl sh nei vmhost

$ bgpctl sh nei vmhost                                                                                                                                                                    
BGP neighbor is 192.168.87.48, remote AS 65002                                                                                                                                                                     
 Description: vmhost                                                                                                                                                                                               
  BGP version 4, remote router-id 192.168.87.48                                                                                                                                                                    
  BGP state = Established, up for 09:06:25                                                                                                                                                                         
  Last read 00:00:21, holdtime 90s, keepalive interval 30s                                                                                                                                                         
  Neighbor capabilities:                                                                                                                                                                                           
    Multiprotocol extensions: IPv4 unicast                                                                                                                                                                         
    Route Refresh                                                                                                                                                                                                  
    Graceful Restart: Timeout: 90, restarted, IPv4 unicast                                                                                                                                                         
    4-byte AS numbers                                                                                                                                                                                              
                                                                                                                                                                                                                   
  Message statistics:                                                                                                                                                                                              
                  Sent       Received                                                                                                                                                                              
  Opens                    3          3                                                                                                                                                                            
  Notifications            0          2                                                                                                                                                                            
  Updates                  3          6                                                                                                                                                                            
  Keepalives            1499       1499                                                                                                                                                                            
  Route Refresh            0          0                                                                                                                                                                            
  Total                 1505       1510                                                                                                                                                                            
                                                                                                                                                                                                                   
  Update statistics:                                                                                                                                                                                               
                  Sent       Received                                                                                                                                                                              
  Updates                  0          1                                                                                                                                                                            
  Withdraws                0          0                                                                                                                                                                            
  End-of-Rib               1          1                                                                                                                                                                            
                                                                                                                                                                                                                   
  Local host:         192.168.87.41, Local port:    179                                                                                                                                                            
  Remote host:        192.168.87.48, Remote port: 13528                                                                                                                                                            
                                                                                                                                                                                                                   
$

By the way, as you can see, bgpctl supports shortened commands, e.g. sh nei instead of show neighbor.

Now look for that VMs route:

desktop: bgpctl show rib

$ sudo bgpctl show rib
flags: * = Valid, > = Selected, I = via IBGP, A = Announced, S = Stale
origin: i = IGP, e = EGP, ? = Incomplete

flags destination          gateway          lpref   med aspath origin
*>    10.0.1.0/24          192.168.87.48      100     0 65002 i
$

So that VMs network, 10.0.1/24, it's there! Now check if the system routing table was updated and has this route:

desktop

$ route -n get 10.0.1.45   
   route to: 10.0.1.45
destination: 10.0.1.0                                                                                                                                                                                              
       mask: 255.255.255.0                                                                                                                                                                                         
    gateway: 192.168.87.48                                                                                                                                                                                         
        fib: 0                                                                                                                                                                                                     
  interface: re0                                                                                                                                                                                                   
      flags:                                                                                                                                                                               
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire                                                                                                                                             
       0         0         0         0      1500         1         0                                                                                                                                               
$ ping -c 1 10.0.1.45                                                                                                                                                                     
PING 10.0.1.45 (10.0.1.45): 56 data bytes                                                                                                                                                                          
64 bytes from 10.0.1.45: icmp_seq=0 ttl=63 time=0.192 ms                                                                                                                                                           
                                                                                                                                                                                                                   
--- 10.0.1.45 ping statistics ---                                                                                                                                                                                  
1 packets transmitted, 1 packets received, 0.0% packet loss                                                                                                                                                        
round-trip min/avg/max/stddev = 0.192/0.192/0.192/0.000 ms                                                                                                                                                         
$

Whoa, things work as expected!

Conclusion

As mentioned already, similar result could be achieved without using BGP by using either static routes or bridging interfaces differently, but the purpose of this exercise is to get some basic hands-on experience with BGP. Right now I'm looking into extending my setup in order to try more complex BGP schema. I'm thinking about adding some software switches in front of my VMs or maybe adding a second VM host (if budget allows). You're welcome to comment if you have some ideas how to extend this setup for educational purposes in the context of BGP and networking.

As a side note, I really like openbgpd so far. Its configuration file format is clean and simple, documentation is good, error and information messages are clear, and CLI has intuitive syntax.

Configuring macOS-like screenshotting in Openbox

For many years my way of taking screenshots was pretty trivial. I would execute something like sleep 5 && import -window root screenshot.png, switch over to the virtual desktop I want to screenshot and get this png file. If I need to have only some part of it, I'd cut it in GIMP.

A couple of years back when I've started using macOS at work, I googled up it screenshotting shortcuts. They seemed pretty weird, e.g. Command-Control-Shift-3, where 3 means entire screen and 4 means a user-selected region. While I don't know if there's some logic in choosing 3 and 4 for that (why not any other numbers?), I found that it's extremely convenient to take a screenshot of part of the screen and save it to a clipboard. Moreover, I found that I use this feature almost every day to capture parts of terminal window, highlighting some interesting bits from websites for posting on IM and other stuff where image is better than text.

Of course, when I'm running Openbox, using Gimp to achieve the same things starts feeling extremely cumbersome, so I decided to configure Openbox to have similar keybindings for taking screenshots.

First, I wrote a shell script to make things a little easier: screenshot.sh. It uses the import tool from ImageMagick and xclip.

It just accepts two options:

• -r (stands for rootwindow) tells to capture entire screen, otherwise user has to select a region,
• -f (stands for file) tells to save a screenshot to a file (name will be auto-generated and include date), otherwise saves a screenshot into a clipboard.

And, finally, keybindings configuration for ~/.config/openbox/rc.xml:

    <keybind key="A-S-3">
      <action name="execute">
        <execute>~/bin/screenshot.sh -r -f</execute>
      </action>
    </keybind>
    <keybind key="A-S-W-3">
      <action name="execute">
        <execute>~/bin/screenshot.sh -r</execute>
      </action>
    </keybind>
    <keybind key="A-S-4">
      <action name="execute">
        <execute>~/bin/screenshot.sh -f</execute>
      </action>
    </keybind>
    <keybind key="A-S-W-4">
      <action name="execute">
        <execute>~/bin/screenshot.sh</execute>
      </action>
    </keybind>

Help on Openbox keybindings configuration is here.

The end of my Firefox story?

My history of using web browsers is not short, but not vast. I've started using Linux around 2000 IIRC, and my first DE was KDE and my first browser was Konqueror.

Here's how it looked (screenshot from Wikipedia):

As KDE was pretty resource heavy, and also building from source took a lot of time, I had started looking for a replacement. After trying out various DEs and WMs eventually I had moved to fluxbox and then to openbox a couple of years later. As I switched away from KDE, there was no reason to use Konqueror either, so I switched to Mozilla.

Back then it looked like this (screenshot from testingeducation.org):

Even at that time Mozilla was not on a light side. Also, in additional to browser, it included Mail and IRC client and some other stuff I forgot. Not quite unix-ish "Do One Thing and Do It Well", right?

Fortunately, in 2002 the first light-weight version of Mozilla became available; additional software like IRC and mail clients was ripped out, it was just a browser. Initially it was called Phoenix, then Firebird and finally Firefox. I was happy to see a project like that and switched to it pretty early (most probably while it was still called Firebird).

Fast forward to 2007 (or 2008). Co-worker showed me Vimperator. It seemed awkward initially, but after a little while I didn't want to switch back. Man, it get really addictive once you get used to it.

Eventually this firefox/vimperator combination became even more valuable to me. I spend probably 90% (or even more) of time either in a terminal or in a browser. Also, from time to time I use different computers with different OSes: FreeBSD, macOS, Windows, Linux. And firefox/vimperator allows to rapidly setup my development environment as it's available for all these OSes, and I just need to copy my tiny .vimepratorrc and that's it. Additionally, this convenient vi-like key binding system allows me not to care about OS-specific shortcuts (like switching/closing tabs, etc).

BTW, I recommend to take a look at MobaXterm if you're looking for a handy terminal emulator for Windows.

November, 2017. Situation with vimperator is not good. Firefox is switching to the new multiprocess architecture called e10s. Firefox 57 drops non-WebExtensions-based addons, with vimperaror being one of them. This is sad. I'm still using Firefox ESR while it's supported, but that won't last that long (image from https://www.mozilla.org/en-US/firefox/organizations/faq/):

Time to looks for alternatives. There ain't many.

As I'd love to keep my environment consistent across all OSes I use, I need cross-platform support. This doesn't work for most of the stand-alone browser projects like vimb and surf. However, qutebrowser does seem to provide binaries for many OSes. There are some obvious drawbacks of using tiny stand-alone browsers like that though, like no extensions (unless it supports some compatibility layer) and probably different level of stability on different OSes (depending on what core developers actively use), but I think it's worth checking out.

Another interesting option is Tridactyl which aims to provide WebExtensions based vimperator replacement. It looks like it's in beta stage right now, development is fairly active. Really hope that it'll be successful.

Creating OpenBSD guest with libvirt/bhyve

I've been asked a couple of times how to setup OpenBSD guest with libvirt/bhyve. It's fairly straight-forward, but minimal libvirt version required for that is 3.5.0 because it's the first version that allows to specify vgaconf settings.

First, download the installation image: https://ftp.openbsd.org/pub/OpenBSD/6.1/amd64/install61.fs and create a disk image:

truncate -s 2G openbsd61.raw

Create an initial XML (pay attention to the vgaconf='off' bit):

Now with virsh do:

virsh # define /path/to/openbsd61.xml
Domain openbsd61 defined from /path/to/openbsd61.xml

virsh # start openbsd61
Domain openbsd61 started

virsh # vncdisplay openbsd61                                                                                                                                                                                       
127.0.0.1:0                                                                                                                                                                                                        

Using VNC client connect to the guest at the specified port:

vncviewer :0

This gives a boot loader prompt. For some reason, it doesn't set root device properly, so I have to do:

set device hd1a
boot

Then there'll be a number of installer questions (where I usually accept defaults) until it asks what disk should be used as a root device. It's important to check this carefully and choose the right one (you can find it by its size for example), otherwise it might just try to override the install image.

When the installation finishes, shutdown the guest, go back to virsh and edit the domain xml:

virsh # edit openbsd61

And remove the disk block corresponding to install61.fs. And then start domain again:

virsh # start openbsd61   
Domain openbsd61 started  

Now you should be able to connect to the guest via VNC or via SSH.

PS My sample xml uses the autoport feature that will be available only in libvirt 3.7.0. If you're using an earlier version, specify the VNC port explicitly:

<graphics type='vnc' port='5904'>