Development

Build device and architecture

It is recommended that you have a dedicated Raspberry Pi to build the Antennas snap. Ideally the build pi would have at least 4gb of memory.

This snap must be built and run on arm64. If you build the snap, or any parts, for a different architecture, you will receive a runtime error similar to this: cannot execute binary file: Exec format error.

I've previously, successfully setup a build pi on a Raspberry Pi 4b running Ubuntu Desktop 22.04 LTS, and on a Raspberry Pi 5 running Ubuntu Server 23.10 using the instructions below.

Build tools

Install snapcraft if you haven't already:

sudo snap install --classic snapcraft

As of 2021-10-10, multipass candidate on arm64 ubuntu-desktop doesn't work when running snapcraft. Install and configure lxd instead:

snapcraft --use-lxd # then enter "y"

Set this environment variable in your ~/.bashrc to use lxd by default: SNAPCRAFT_BUILD_ENVIRONMENT=lxd instead of passing --use-lxd every time.

Run snapcraft clean && snapcraft for a fresh build. If you are sure you only changed a specific part, you can clean only that part with snapcraft clean part to save time on subsequent builds.

Installing the built snap

It is recommended that you have a dedicated Raspberry Pi to test this snap. Follow instructions on Getting Started.

Transfer the built snap from your "build pi" to the "test pi" with sftp.

If you have previously installed this snap, remove it:

sudo snap remove --purge antennas

Since your snap was built locally and not signed/asserted by the snap store, you must install it with the dangerous flag:

sudo snap install --dangerous ./antennas_1_arm64.snap

Tip: Add some aliases to your test pi's ~/.bashrc (reconnect via ssh for changes to take effect):

alias resnap="reinstall && repermission && repassword && reenable"
alias reinstall="sudo snap remove --purge antennas && sudo snap install --dangerous antennas_1_arm64.snap"
alias repermission="sudo snap connect antennas:firewall-control && sudo snap connect antennas:network-control"
alias repassword="sudo antennas.config set --country-code=us --wifi-ssid=Test --wifi-password"
alias reenable="sudo snap start --enable antennas"

Overclocking (Optional)

Warning: This has only been tested on a Raspberry Pi 4b. It has not been tested on a Raspberry Pi 5 (yet).

If you have decent cooling on your build pi then you can overclock it for faster build times. The instructions are similar to overclocking Ubuntu Core except you will have to manually add force_turbo=1 to /boot/firmware/config.txt and then reboot.