Mion update strategy

The purpose of this document is to outline the update strategy for systems running mion in order to

• ensure mion and upstream Yocto and OpenEmbedded security updates can be applied to system with in a timely manner (security)
• allow end users to deploy updated versions of they applications to the system (application updates)

1. Simple update strategy using ONIE

In the interest of keeping things as simple as possible at the moment the only currently supported update mechanism for mion is by building from the most recent sources and installing an updated image using ONIE.

Support for the Mender update mechanism has been removed as it was complex to maintain and was not being used.

The NGL project maintainers will updates all mion upstream repos (submodules) once per week, usually on a Monday, and verify that the images build correctly as expected in CI. Users can watch for the submodule update commit, build an updated image and deploy using ONIE. If this update frequency is too slow it is possible for the end users to update their own submodules and build from sources.

ISSUES

• There is currently no mechanism for saving state or configs on the machine
• Upstream updates (and potentially security fixes) are delayed by up to a week
• Changing any part of the system requires a full reinstall using ONIE

2. System update using ONIE and IPK package feeds *WIP*

It is our intention to extend the scenario outlined above by enabling users to update parts of the system using a standard package manager (currently opkg/ipk) however this is currently WIP.