Gluon contains an automatic update system which can be configured in the site configuration.

Building Images

By default, the autoupdater is disabled (as it is usually not helpful to have unexpected updates during development), but it can be enabled by setting the variable GLUON_AUTOUPDATER_ENABLED to 1 when building. It is also possible to override the default branch during build using the variable GLUON_AUTOUPDATER_BRANCH.

If a default branch is set neither in site.conf nor via GLUON_AUTOUPDATER_BRANCH, the default branch is implementation-defined. Currently, the branch with the first name in alphabetical order is chosen.

A manifest file for the updater can be generated with make manifest. A signing script (using ecdsautils) can be found in the contrib directory. When creating the manifest, the PRIORITY value may be defined by setting GLUON_PRIORITY on the command line or in

GLUON_PRIORITY defines the maximum number of days that may pass between releasing an update and installation of the images. The update probability will start at 0 after the release time declared in the manifest file by the variable DATE and then slowly rise up to 1 when GLUON_PRIORITY days have passed. The autoupdater checks for updates hourly (at a random minute of the hour), but usually only updates during its run between 4am and 5am, except when the whole GLUON_PRIORITY days and another 24 hours have passed.

GLUON_PRIORITY may be an integer or a decimal fraction.

If GLUON_RELEASE is passed to make explicitly or it is generated dynamically in, care must be taken to pass the same GLUON_RELEASE to make manifest, as otherwise the generated manifest will be incomplete.

Manifest format

The manifest starts with a short header, followed by the list of firmwares and signatures. The header contains the following information:

DATE=2020-10-07 00:00:00+02:00
  • BRANCH is the autoupdater branch name that needs to match the nodes configuration.

  • DATE specifies when the time period for the update begins. Nodes will do their regular update during a random minute between 4:00 and 4:59 am. Nodes might not always have a reliable NTP synchronization, which is why a fallback mechanism exists, that checks for an update, and will execute if DATE is at least 24h in the past.

  • PRIORITY can be configured as GLUON_PRIORITY when generating the manifest or in, and defines the number of days over which the update should be stretched out after DATE. Nodes will calculate a probability based on the time left to determine when to update.

Automated nightly builds

A fully automated nightly build could use the following commands:

git pull
# git -C site pull
make update
make clean GLUON_TARGET=ath79-generic
NUM_CORES_PLUS_ONE=$(expr $(nproc) + 1)
contrib/ $SECRETKEY output/images/sysupgrade/experimental.manifest

rm -rf /where/to/put/this/experimental
cp -r output/images /where/to/put/this/experimental


We suggest to have following directory tree accessible via http:


The server must be available via IPv6.

Command Line

These commands can be used on a node:

# Update with some probability
# Force update check, even when the updater is disabled
autoupdater -f
# If fallback is true the updater will perform an update only if the timespan
# PRIORITY days (as defined in the manifest) and another 24h have passed
autoupdater --fallback