Build, Deploy and Validate Cassini Image¶
The recommended approach for image build setup and customization is to use the kas build tool. To support this, Cassini provides configuration files to setup and build different target images, different distribution image features, and set associated parameter configurations.
This page first briefly describes below the kas configuration files provided with Cassini, before guidance is given on using those kas configuration files to set up the Cassini distribution on a target platform.
Note
All command examples on this page can be copied by clicking the copy button. Any console prompts at the start of each line, comments, or empty lines will be automatically excluded from the copied text.
The meta-cassini-config/kas
directory contains kas configuration files to
support building and customizing Cassini distribution images via kas. These kas
configuration files contain default parameter settings for a Cassini distribution
build. Here, the files are briefly introduced, classified into three ordered
categories:
Base Configs: Configures common software components
cassini.yml
to build an image for the Cassini distribution.
cassini-dev.yml
to build a Cassini image suitable for development (e.g. allowing root login without password)
cassini-sdk.yml
to build a Cassini image with additional tools for software development.Build Modifier Configs: Set and configure features of the Cassini distribution
tests.yml
to include run-time validation tests into the image.
security.yml
to build a security-hardened Cassini distribution image.Target Platform Configs: Set the target platform
For information on supported targets in Cassini and corresponding value for
MACHINE
variable, refer to Target Platforms.
These kas configuration files can be used to build a custom Cassini distribution by passing one Base Config, zero or more Build Modifier Configs, and one Target Platform Config to the kas build tool, chained via a colon (:) character. Examples for this are given later in this document.
In the next section, guidance is provided for configuring, building and deploying Cassini distributions using these kas configuration files.
Build Host Environment Setup¶
This documentation assumes an Ubuntu based build host, where the build steps have been validated on the Ubuntu 20.04 LTS (Focal Fossa) and 22.04 LTS (Jammy Jellyfish).
Note
The following build steps can be run on Ubuntu 18.04 LTS version, however since Ubuntu 18.04 doesn’t provide required versions of development tools (such as Python 3.8), then the extra Yocto buildtools environment setup is needed.
Note
When using Ubuntu 22.04, installing Python 3.8 or 3.9 is recommended as
kas 3.2 has dependencies which are incompatible with the version
of setuptools
that ships with Python 3.10.
A number of package dependencies must be installed on the Build Host to run build scenarios via the Yocto Project. The Yocto Project documentation provides the list of essential packages together with a command for their installation.
The recommended approach for building Cassini is to use the kas build tool. To install kas:
pip3 install --upgrade kas==3.2
For more details on kas installation, see kas Dependencies & installation.
To deploy a Cassini distribution image onto the supported target platform,
bmap-tools
is used. This can be installed via:
sudo apt install bmap-tools
Note
The Build Host should have at least 65 GBytes of free disk space to build a Cassini distribution image.
Download¶
The meta-cassini
repository can be downloaded using Git, via:
# Change the tag or branch to be fetched by replacing the value supplied to
# the --branch parameter option
git clone https://gitlab.com/Linaro/cassini/meta-cassini.git --branch mickledore-dev
cd meta-cassini
Build and Deploy¶
Refer to the platform guides instructions on how to build and deploy the Cassini images on supported platforms:
Run¶
To run the deployed Cassini distribution image, simply boot the target platform.
The Cassini distribution image can be logged into as cassini
user.
The distribution can then be used for deployment and orchestration of application workloads in order to achieve the desired use-cases.
Validate¶
As an initial validation step, check that the appropriate Systemd services are running successfully,
docker.service
k3s.service
These services can be checked by running the command:
systemctl status --no-pager --lines=0 docker.service k3s.service
And ensuring the command output lists them as active and running.
More thorough run-time validation of Cassini components are provided as a series
of integration tests, available if the meta-cassini-config/kas/tests.yml
kas
configuration file was included in the image build.
Reproducing the Cassini Use-Cases¶
This section briefly demonstrates simplified use-case examples, where detailed instructions for developing, deploying, and orchestrating application workloads are left to the external documentation of the relevant technology.
Deploying Application Workloads via Docker and K3s¶
This example deploys the Nginx web server as an application workload, using
the nginx
container image available from Docker’s default image repository.
The deployment can be achieved either via Docker or via K3s, as follows:
Boot the image and log-in as
cassini
user.Ensure the target device can access the internet
ping www.linaro.org
Deploy the example application workload:
Deploy via Docker
3.1. Run the following example command to deploy via Docker:
sudo docker run -p 8082:80 -d nginx
3.2. Confirm the Docker container is running by checking its
STATUS
in the container list:sudo docker container list
Deploy via K3s
3.1. Run the following example command to deploy via K3s:
cat << EOT > nginx-example.yml && sudo kubectl apply -f nginx-example.yml apiVersion: v1 kind: Pod metadata: name: k3s-nginx-example spec: containers: - name: nginx image: nginx ports: - containerPort: 80 hostPort: 8082 EOT3.2. Confirm that the K3s Pod hosting the container is running by checking that its
STATUS
isrunning
, using:sudo kubectl get pods -o wide
After the Nginx application workload has been successfully deployed, it can be interacted with on the network, via for example:
wget localhost:8082
Note
As both methods deploy a web server listening on port 8082, the two methods cannot be run simultaneously and one deployment must be stopped before the other can start.