Switchboard RPi Setup

This directory contains the scripts for configuring RPi SD cards for RPis running as test machines under Switchboard. See the Design Doc.

Debian supports RPi now: https://wiki.debian.org/RaspberryPi. Visit https://raspi.debian.net/tested-images/ for images.

The image currently used is:

https://raspi.debian.net/verified/20210629_raspi_4_bullseye.img.xz

Download that and burn it to an SD card. After it has been burned, reload the SD card and run:

./configure-image.sh <machine-name>

Once the SD card has been placed in an RPi and is running in the lab:

1. Add the hostname to //skolo/ansible/hosts.ini.
2. Run:

     $ cd //skolo/ansible/
     $ ansible-playbook ./switchboard/setup-switchboard-rpi.yml \
         --extra-vars variable_hosts=<machine-name>

     $ cd //machine
     $ make build_test_machine_monitor_rpi
     $ TARGET=<machine-name> make push_test_machine_monitor_rpi

Now the RPi should be fully setup with adb, idevice-*, a recent copy of authorized_keys, and running test_machine_monitor.

Testing outside the skolo.

This only applies to testing RPis outside the skolo.

Outside the skolo the RPi will not have a metadata server to talk to, so test_machine_monitor will fail to run. You can get test_machine_monitor to run by supplying another form of Google Application Credentials. One way is to create a service account key, copy it over the RPI, and then set an Env variable in the test_machine_monitor.service file.

1. Use an existing service account key, or visit the cloud console page and generate a new key.

2. Copy that key over to the RPi:

   scp key.json chrome-bot@192.168.1.107:/home/chrome-bot/key.json
   

3. Update the test_machine_monitor.service to add the GOOGLE_APPLICATION_CREDENTIALS environment variable that points to the service account key.

   [Unit]
   Description=test_machine_monitor
   After=syslog.target network.target
   
   [Service]
   Type=simple
   User=chrome-bot
   Environment=GOOGLE_APPLICATION_CREDENTIALS=/home/chrome-bot/key.json
   ExecStart=/usr/local/bin/test_machine_monitor \
      --start_switchboard
   Restart=always
   
   [Install]
   WantedBy=multi-user.target
   

4. Force the new config to be loaded:

   systemctl daemon-reload
   

5. Restart the service

   systemctl restart test_machine_monitor