====== libostree ======


[[https://ostree.readthedocs.io/en/latest/|Libostree]], previous known as OSTree, is both a shared library and suite of command line tools that combines a "git-like" model for committing, downloading and downloading bootable filesystem trees.

====== meta-updater ======

Yocto/OpenEmbedded layer [[https://github.com/advancedtelematic/meta-updater|meta-updater]] provides libostree and Aktualizr in Automotive Grade Linux (AGL). [[https://github.com/advancedtelematic/aktualizr|Aktualizr]] is a C++ reference implementation of SOTA OTA update client integrated with libostree.

====== Demo ======

Although the straight-forward way for doing [[https://docs.atsgarage.com/quickstarts/automotive-grade-linux.html|Software OTA updates in AGL is through ATS Garage]], it is also possible to use directly OSTree built with the **agl-sota** feature and **meta-updater**. 

Required hardware for setting up a demo Raspberry Pi 3:
  * Raspberry Pi 3
  * microSD card
  * Build machine
  * Router and a couple of Ethernet cables

For example, the following procedure performs an update of AGL image on Raspberry Pi and adds the simple text editor **nano**:

  * Built AGL image for Raspberry Pi 3 and boot it on the board.
  * Add the following line to conf/local.conf to add **nano** and rebuild the image:

  IMAGE_INSTALL_append = " nano "

  * On the host, go to directory:

  cd tmp/deploy/images/raspberrypi3/ostree_repo

  * On the host, start a simple web server:

  python -m SimpleHTTPServer 8000

  * On the Raspberry Pi 3, configure OSTree remote:

  ostree remote add --no-gpg-verify agl http://<host_ip>:8000

  * On the Raspberry Pi 3, check for new updates:

  ostree pull agl raspberrypi3

  * On the Raspberry Pi 3, deploy an update:

  ostree admin deploy agl:raspberrypi3

  * On the Raspberry Pi 3, reboot the system to apply the update:

  systemctl reboot

  * On the Raspberry Pi 3, verify that **nano** has been successfully provided with the update.