Quarkus Feature Flags - Cron
If you want to use a flag evaluator to match a specific CRON expression in your application you’ll need to add the io.quarkiverse.flags:quarkus-flags-cron extension to your build file first.
For instance, with Maven, add the following dependency to your POM file:
<dependency>
<groupId>io.quarkiverse.flags</groupId>
<artifactId>quarkus-flags-cron</artifactId>
<version>{project-version}</version>
</dependency>The extension provides the CronFlagEvaluator that can be used to compute the current value of a feature flag based on the current date-time obtained from the system clock in the default time-zone and the configured CRON expression.
A typical feature flag configuration may look like:
quarkus.flags.runtime.delta.value=true (1)
quarkus.flags.runtime.delta.meta.evaluator=quarkus.cron (2)
quarkus.flags.runtime.delta.meta.cron-expr=* * * * mon (3)| 1 | Flag delta is enabled by default. |
| 2 | The CronFlagEvaluator is used to compute the current value of the feature flag. |
| 3 | The current date-time must match the given CRON expression. In this particular case, the flag will be enabled every Monday. |
By default, the Unix/crontab syntax is used. However, it is also possible to use the syntax from Cron4j, Quartz and Spring. For example, quarkus.flags.runtime.delta.meta.cron-type=QUARTZ.
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