tpmccallum / spin-trigger-cron

Experimental Cron trigger for Spin

Install from release

spin plugins install --url https://github.com/fermyon/spin-trigger-cron/releases/download/canary/trigger-cron.json

Build From source

You will need Rust and the pluginify plugin (spin plugins install --url https://github.com/itowlson/spin-pluginify/releases/download/canary/pluginify.json).

cargo build --release
spin pluginify --install

Test

You will need to build and run the spin components. Change the cron expression if needed.

cd guest
spin build --up

Installing the template

You can install the template using the following command:

spin templates install --git https://github.com/fermyon/spin-trigger-cron

Once the template is installed, you can create a new application using:

spin new -t cron-rust hello_cron --accept-defaults

To run the newly created app:

cd hello_cron
spin build --up

Trigger Configuration

The trigger type is cron and there are no application-level configuration options.

The following options are available to set in the [[trigger.cron]] section:

Name	Type	Required?	Description
component	string or table	required	The component to run on the schedule given in cron_expression. (This is the standard Spin trigger component field.)
cron_expression	string	required	The cron expresison describing the schedule on which to execute the component.

Building Cron Components

Currently only a Rust SDK is supported for guest components. The spin-cron-sdk along with the spin_sdk crate can be used to build cron components. The guest code must have a function decorated with the #[cron_component] macro. See guest/src/lib.rs for an example in rust.

The signature of the function must be fn handle_cron_event(metadata: Metadata) -> Result<(), Error>.

The Metadata object contains a single field timestamp which contains the duration since 00:00:00 UTC on 1 January 1970 (the Unix epoch) in seconds.