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Updates/deployment

steamos-update

This chapter will describe how steamos-update is being used to deploy builds on target HoloISO instance.

steamos-update is a bash script that does following things:

If steamos-update check is being ran:

  1. Downloads latest update metadata from ${MIRROR, where MIRROR is being set in /etc/steamos-atomupd/mirror}/holoiso-images in following fashion:

    • Checks if there's update branch override (i.o.w subbranch) set by ${UPDATE_BRANCH_OVERRIDE} either by default in /etc/holoiso-release or in /etc/manual-enroll-override set by holoiso-enroll-build, in which case, the endpoint link turns into ${MIRROR}/holoiso-images/${UPDATE_BRANCH_OVERRIDE}/latest_${UPD_BRANCH}.releasemeta
    • Else? Set ${MIRROR}/holoiso-images/latest_${UPD_BRANCH}.releasemeta and download the metadata from there.

    Wonder if something is going wrong? By default, Steam client checks for those exit codes:

    • Exitcode 7 means that no update is available
    • Exitcode 0 means that update is available/finished updating/successful return
    • Anything else means that update failed and the PID should be terminated immediately

  2. If an update exists ("${STAGING_OS_TAG}" > "${OS_TAG}"):

    • Arms "ready-to-update" condition (/tmp/steamos-ready-to-deploy)

    Else? Report to the user that either: - System is up to date - "Your version (${OS_TAG}) is newer than currently available (${STAGING_OS_TAG}). Please wait for next update to appear available in branch \"${UPD_BRANCH}\" for installation."

If everything is correct, next "Update" press in Steam client will run steamos-update without any arguments, and here's what it will do now:

  1. It will download the latest release subvolume according to the update metadata to /home/.steamos/updatecontainer/${STAGING_OS_TAG}

  2. After downloading the subvolume file, it will download the sha256 sum to verify that everything went smoothly while downloading

    • This will engage verification process where:

    If currently downloaded file sha matches the endpoint sha:

    • Good enough to hand-off!

    Else?

    • Delete the entire update container, and abort any hand-offs

  3. If everything is correct, it will hand-off the arguments file to steamos-update-os ${argdata}

steamos-update-os

steamos-update-os applies the images, and does any post-update hooks it needs to do

  1. If hand-off is being requested, check that BOTH argument data exists and sentinel is armed.
  2. If everything looks good, proceed to run steamos-update-os normally

Process

  1. Install subvolume via holo-deploy install ${installfile}
  2. Apply postupdate hooks via holo-deploy switch /rootfs/${installfile}
  3. Clean up (remove /home/.steamos/updatecontainer contents)
  4. Done

This sums up the normal update process via steamos-update.

Manual installation

If you would like to manually install customly-built/or official, but downloaded from the server image build, follow these instructions:

  1. Make sure that your current installation is set to RW (steamos-readonly disable)

Let's assume that our file is called INSTALL.img or INSTALL.img.zst, and we wrap it into a variable called installfile,

  1. Install subvolume via holo-deploy install ${installfile}
  2. Apply postupdate hooks via holo-deploy switch /rootfs/${installfile}
  3. Reboot the device, and see if GRUB shows your new boot option (SteamOS, subvolume /rootfs/INSTALL or SteamOS, subvolume /rootfs/INSTALL with linux-kernel)

That is all you need to install subvolume images on your own.