Creating NetBSD images for Google Compute Engine

This repository holds tools to build a NetBSD image for use on Google Compute Engine (GCE). GCE is part of the Google Cloud Platform.

[!IMPORTANT] NetBSD only supports virtio-net for networking; there is no support for gVNIC and IDPF network interfaces. GCE Gen 3 and Gen 4 virtual machines only support gVNIC.

In practice, this means that you can only run NetBSD on N1, N2, E2 and C2 machine types, not the newer ones.

Running make.bash

make.bash can be run under a GNU/Linux, BSD or macOS operating system. To run the script, you need a few things to be installed:

• bash
• qemu
• cdrtools
• GNU tar (http://pkgsrc.se/archivers/gtar)
• GNU coreutils (http://pkgsrc.se/sysutils/coreutils)
• Python 3
• python-pexpect (http://pkgsrc.se/devel/py-pexpect)

When you run

bash ./make.bash

it will download a distfile for Anita (an automated NetBSD installation tool), which will download and install NetBSD 11 in a virtual machine on the local host. It then adds several tweaks to ensure that networking and storage will work on GCE and packs the image into a tar.gz file.

Optionally, you can give the script an architecture (i386 or amd64), a branch name and the desired root disk size as parameters, for example

bash ./make.bash amd64 HEAD 10G

to install a 64-bit version of NetBSD-current.

How to use the created image (i.e. how to get started on GCE)

The how-to below describes how to do the required operations in a web browser. You can also use the Google Cloud SDK and its gcloud command line tool.

1. Run make.bash as described above.
2. Go to https://console.cloud.google.com/. Log in with your Google account or create a new one. If you never used Google Cloud Platform before, you will need to enter a credit card for billing. Yes, running stuff on GCP costs money.
3. Create a new Cloud project. A project is a collection of resources, such as VMs, storage, logs, etc.
4. In the left hand menu, click “Storage” and create a new bucket.
5. Click on the bucket, then click the “Upload files” button and select the output file that was created in step 1 (e.g. netbsd-amd64-gce.tar.gz).
6. In the left hand menu, select “Compute Engine”, then “Images”. Click “Create Image”, choose a name, and select “Cloud Storage file” as the source. Browse to the file you just uploaded.
7. Select “Instances” from the left hand menu, then “Create Instance”. Select a zone and the amount of CPU and memory. Under the “Boot Disk” heading, click “Change”, select “Custom images” and choose the image you just created. Click the “Create” button at the bottom.
8. You will be transported back to the list of instances, where the instance you created is just starting up. Congratulations! To see the console output, click on the instance name, scroll down and click on “View serial port”.

Using the interactive serial console

You will soon notice that you cannot use the SSH button to connect to the VM. Unfortunately, transferring of SSH keys to the machine does not work yet. To connect to the instance now, you can use the interactive serial console. Click “Edit” on the instance details page, scroll all the way to the bottom and tick the “Enable connecting to serial ports” box.

Now you can click the button labeled “Connect to serial port”. You will get a terminal window in the browser. Log in as root with no password. (This is the first thing you should change!)

Now you can create user accounts and copy SSH keys as you wish. For example, to create a user named myuser, use the following commands:

useradd -m myuser
passwd myuser

To enable the SSH daemon, use the following commands:

echo sshd=YES >> /etc/rc.conf
/etc/rc.d/sshd start

Once sshd is running, you should be able to connect to the instance by pointing your ssh client to the instance’s external IP address.