popufare/experiment/production/Deploy-Install-Notes.md

Deploy Install Notes

There is a facility to update the buses deployed in the fleet with updates. This is necessary as routes, drivers, etc. change.

As the system changes over to a newer version, there will be some legacy system infrastructure to deal with making sure legacy systems aren't updated with new code and the new systems aren't running legacy update scripts.

Legacy System Overview

The script update_loop.sh looks at the list of package checksums and sends them to the server. The server responds with updated packages, including the checksum, file size and server side location.

If the DIU receives this information, update_loop.sh then proceeds to:

• Confirms the reported package is different from the local version
• Checks to make sure the process hasn't been flagged for being aborted (presence of a drop file)
• Generates expected information into temporary files
• scp the remote file locally
• Checks again for an abort drop file
• Runs apply_update.sh with the file, checksum, size, path and package version
• Cleans up

The apply_update.sh script

• Loads common_values.sh
• Confirms checksums are different, aborting install if they are the same
• Proceeds only if the reported checksum is the same as the actual checksum
• Extracts the install.sh script from the downloaded tar.gz package
• Runs install.sh
• fix_pkg_perms.sh as ssh will start to fail when keys or directories the keys are in don't have proper permissions or if executable bits on binaries aren't set properly will cause other processes to fail.

From what I can tell, the following is noteworthy:

• install.sh needs to return a proper value to indicate to apply_update.sh it's been successful
• /tmp/reboot_flag file will be touched if the system needs a reboot

Popufare Installation

Here's my suggestion on how to proceed:

• Popufare will ignore the firmware.tgz package updates
• Popufare will only extract config files (paddles, etc.) from the config.tgz packages and deposits them in the appropriate place
• Popufare will use a new package, popufare_package.tgz, that checks for a "magic" file (/home/bus/config/popufare.witness) and only proceeds if this file is present