Container-Optimized OS is based on, and built using, tools from the open-source Chromium OS project. If you like, you can build a Container-Optimized OS image yourself directly from the Container-Optimized OS source code.
Prerequisites
To build a Container-Optimized OS image, you'll need to install the following tools on your development machine:
git
andcurl
- A package of Chromium scripts called
depot_tools
that includes tools likerepo
andcros_sdk
.
Obtaining the Container-Optimized OS source code
You can download the source code for Container-Optimized OS by using the
repo
tool that is included in depot_tools
.
First, create a directory to store the source code. For example, cos-src
in
your home directory:
mkdir $HOME/cos-src
cd $HOME/cos-src
Now download source code using the following commands:
repo init -u https://cos.googlesource.com/cos/manifest.git \
--repo-url https://chromium.googlesource.com/external/repo.git
repo sync
Building a Container-Optimized OS image
To build Container-Optimized OS, you must create a suitable chroot
environment. You can use the cros_sdk
tool included in depot_tools
to create
and enter a chroot
that's ready for Container-Optimized OS compilation by
running the following command in the source directory that you created in the
previous step:
cd $HOME/cos-src
cros_sdk --enter
Once inside chroot
, you can build the disk image. To build
Container-Optimized OS, specify lakitu
(x86 image) or lakitu-arm64
(Arm image) for the board name as follows:
x86 image
build_packages --board=lakitu
build_image --board=lakitu test
Arm image
build_packages --board=lakitu-arm64
build_image --board=lakitu-arm64 test
In addition to test
, you can build either a base
, or dev
image
by passing the appropriate parameter to the ./build image
script command. If
you don't specify a parameter, the dev
image is built by default.
The dev
image contains some additional debug tools installed on top of the
base
image. The test
image includes the debug tools from the dev
image as
well as tools necessary for running automatic Container-Optimized OS tests.
Attribution Requirements
When you produce a Container-Optimized OS image, you need to fulfill various
attribution requirements of third party licenses. The image generated by a build
contains all relevant attribution information in
/opt/google/chrome/resources/about_os_credits.html
. As a separate build
artifact it is also available as license_credits.html
file in the build output
directory.
Running Your Image
Once you've built your Container-Optimized OS image, you can run the image using KVM, or import the image to a Compute Engine instance.
Running in hypervisor
To boot your image in hypervisor, run the following command:
x86 image
kvm -m 1024 -nographic -net nic,model=virtio -net user,hostfwd=tcp:127.0.0.1:9222-:22 -hda src/build/images/lakitu/latest/chromiumos_test_image.bin
Arm image
sudo apt-get install qemu-system-arm qemu-efi
dd if=/dev/zero of=/tmp/flash0.img bs=1M count=64
dd if=/usr/share/qemu-efi/QEMU_EFI.fd of=/tmp/flash0.img conv=notrunc
sudo qemu-system-aarch64 -m 1024 -cpu cortex-a57 -M virt -nographic \ -pflash /tmp/flash0.img \ -device virtio-scsi-pci,id=scsi \ -drive if=none,file=src/build/images/lakitu-arm64/latest/chromiumos_test_image.bin,id=hd0 \ -device scsi-hd,drive=hd0,bootindex=0 \ -net nic \ -net user,hostfwd=tcp::9222-:22
Booting in this manner leaves the VM's serial port connected to your console,
letting you log in without using SSH. If you're running a test
image, you can
log in with the username/password pair "root/test0000".
Once the VM is started, you can access your dev
or test
image using SSH. To
SSH into the image, use the key generated for that image, as follows:
x86 image
ssh root@localhost -p 9222 -i src/build/images/lakitu/latest/id_rsa
Arm image
ssh root@localhost -p 9222 -i src/build/images/lakitu-arm64/latest/id_rsa
Running on Compute Engine
To import your image to a Compute Engine instance, you must compress the image
into a .tar
file. To compress the image, run the following command:
x86 image
tar -Sczf compressed-image.tar.gz images/lakitu/latest/chromiumos_image.bin --transform 's|images/lakitu/latest/chromiumos_image.bin|disk.raw|'
Arm image
tar -Sczf compressed-image.tar.gz images/lakitu-arm64/latest/chromiumos_image.bin --transform 's|images/lakitu-arm64/latest/chromiumos_image.bin|disk.raw|'
After you've created your .tar
file, you can follow the instructions to
import an existing image
in the Compute Engine documentation.