Pre-Installed Packages
These packages are pre-installed and available to any I/O Runtime user:
/whisk.system/alarms
You can get details about the content of a package by running this command:
aio rt:package:get /whisk.system/alarms
You can execute any of the actions defined in a shared package by using the fully qualified name. For example:
aio rt:action:invoke /whisk.system/alarms/alarm
Alternatively, you can bind any of these packages to your namespace; see the Packages page. When you bind a package, you can set your own default parameters (if any) and run the actions as local to your namespace.
The alarms package can be used to trigger a actions for a single or recurring interval. This is a three-step process:
- Create one or more actions you want to be executed. There is nothing special about these actions; create them as you would any other.
- Create a trigger and specify the frequency. This is what the Alarms package provides.
- Create a rule that links every action to a trigger Every time the trigger is fired, its linked action is executed.
The alarms package contains:
| Entity | Type | Parameters | Description |
|---|---|---|---|
/whisk.system/alarms | package | - | Alarms utility |
/whisk.system/alarms/interval | feed | minutes, trigger_payload, startDate, stopDate | Fire Trigger event on an interval-based schedule |
/whisk.system/alarms/once | feed | date, trigger_payload, deleteAfterFire | Fire Trigger event once on a specific date |
/whisk.system/alarms/alarm | feed | cron, trigger_payload, startDate, stopDate | Fire Trigger event on a time-based schedule using cron |
To create a trigger named my-interval on an interval-based schedule that will fire every 10 minutes until January 31, 2028:
aio rt:trigger:create my-interval \
--feed /whisk.system/alarms/interval \
--param minutes 10 \
--param trigger_payload "{\"name\":\"Vlad\",\"place\":\"Transylvania\"}" \
--param stopDate "2028-01-31T23:59:00.000Z"
To create a trigger that fires once:
aio rt:trigger:create my-interval \
--feed /whisk.system/alarms/once \
--param trigger_payload "{\"name\":\"Vlad\",\"place\":\"Transylvania\"}" \
--param stopDate "2028-01-31T23:59:00.000Z"
--param deleteAfterFire "rules"
Finally, to create a trigger that fires every hour on a time-based schedule using cron:
aio rt:trigger:create my-interval \
--feed /whisk.system/alarms/alarm \
--param cron "0 * * * *" \
--param trigger_payload "{\"name\":\"Vlad\",\"place\":\"Transylvania\"}" \
--param startDate "2025-10-17" \
--param stopDate "2026-10-31T23:59:00.000Z"
Here are some examples of how to set various cron values - for more information, check this page:
* * * * *: The Trigger fires at the top of every minute0 * * * *: The Trigger fires at the top of every hour0 */2 * * *: The Trigger fires every 2 hours (that is, 02:00:00, 04:00:00, ...)0 9 8 * *: The Trigger fires at 9:00:00AM (UTC) on the eighth day of every month
Next steps
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