By design, non-devmode snaps installed from the store are automatically updated on a regular cadence. By default, the
snapd daemon checks for updates 4 times each day.
Controlling refresh frequency
Sometimes the user wishes to have snaps refresh at known times, rather than the default. This can be achieved with the
snap set system refresh.timer command. The user can specify a range of days or times when they’d prefer refreshes to occur. The following example sets the
snapd daemon to refresh snaps only between 4AM and 7AM and between 7PM and 10:10PM.
$ snap set system refresh.timer=4:00-7:00,19:00-22:10
Examples of possible refresh timers:
||Mondays at 10:00, Fridays at 15:10|
||Mondays at 10:00 and 15:00, Fridays at 10:00 and 15:00|
||Monday to Wednesday and on Friday, twice between 9:00 and 11:10|
||Mondays, some time between 9:00 and 11:00, and on Wednesdays, some time between 22:00 and 23:00|
||Monday and on Wednesday, at 0:00|
||Monday through Wednesday on the 2nd week of the month, between 23:00 and 24:00|
||Last Friday of the month, from 23:00 to 1:00 the next day|
See Timer string format for a comprehensive breakdown of the syntax used to define times and frequencies.
Users can force-check and update snaps with
$ snap refresh gnome-system-monitor 3.28.2 from 'canonical' refreshed gnome-calculator 3.28.2 from 'canonical' refreshed flock-chat 2.2.192 from 'flock-chat' refreshed gnome-characters 3.28.2 from 'canonical' refreshed
Once a refresh has happened, use the
snap changes and
snap change <num> command to get details about what changed.
$ snap changes ID Status Spawn Ready Summary 2052 Done today at 09:34 BST today at 09:35 BST Auto-refresh 7 snaps 2053 Done today at 15:16 BST today at 15:17 BST Refresh snaps "gnome-calculator", "flock-chat", "gnome-characters", "gnome-system-monitor"
$ snap change 2053 Status Spawn Ready Summary Done today at 15:16 BST today at 15:16 BST Ensure prerequisites for "gnome-calculator" are available Done today at 15:16 BST today at 15:16 BST Download snap "gnome-calculator" (199) from channel "stable" Done today at 15:16 BST today at 15:16 BST Fetch and check assertions for snap "gnome-calculator" (199) ⋮ Done today at 15:16 BST today at 15:16 BST Start snap "gnome-system-monitor" (54) services Done today at 15:16 BST today at 15:16 BST Clean up "gnome-system-monitor" (54) install Done today at 15:16 BST today at 15:16 BST Run configure hook of "gnome-system-monitor" snap if present