Brigade Cron: A cron gateway for Brigade

This is a gateway for Brigade. It provides a Brigade user with the ability to schedule a specific Brigade job for a specific project.

Usage

• Clone this repository
• helm inspect values ./charts/brigade-cron > values.yaml
• Edit values.yaml
• helm install -n my-brigade-cron ./charts/brigade-cron -f values.yaml

You can take a look in the example/ directory for an example.

Description

This project creates one CronJob which triggers one particular event for a particular project. You can safely install many of these into the same cluster for the same project. You can think of this as a crontab entry.

Cron Time Format

You can determine how frequently your Cron runs by using the schedule: field.

Note that the cluster time is the time used. Not your local time.

The Cron time format is determined by Kubernetes itself. But the format is described in detail in the Wikipedia Cron page

There are a few keyword entries: @hourly, @daily, @weekly, @monthly, @yearly. Each of these fires at the beginning of the time period (top of the hour, beginning of the day, first of the week, and so on).

In addition to the keywords, the Vixie Cron format is supported:

MINUTE HOUR DAY-OF-MONTH MONTH DAY-OF-WEEK

For example, to run every hour, use:

0 0 * * *

This implementation also supports some of the advanced behaviors. For example, to run every five minutes, you can do:

*/5 * * * *

I have not tested more advanced things like:

1 23 * JAN MON-WED

The above should run the job at 11:01 PM every Mon, Tue, and Wed in January. But again, it is untested.

Projects

This gateway will work with any existing Brigade project. If you have the Brig client installed, you can see your Brigade projects like this:

$ brig project list
NAME                     	ID                                                            	REPO
deis/test-private-testbed	brigade-544b459e6ad7267e7791c4f77bfd1722a15e305a22cf9d3c60c5be	github.com/deis/test-private-testbed
deis/empty-testbed       	brigade-830c16d4aaf6f5490937ad719afd8490a5bcbef064d397411043ac	github.com/deis/empty-testbed

You can use either the NAME or ID in your brigade-cron configuration.

Events

The Brigade-Cron gateway does not define its own event (though we give examples of using a cron event).

Essentially, you can use any event you want. You just need to make sure that the event in your config file matches the event you want to fire in the brigade.js file.

For example, you can configure brigade-cron with a values.yaml file like this:

event: "my_event"

schedule: "@hourly"
project: "technosophos/brigade-cron"
ref: "refs/heads/master"
payload: "HELLO"

# You might need to override this.
rbac:
  enabled: false

image:
  registry: deis
  name: brig
  tag: latest

In the above, the event is set to my_event. To handle that event in a brigade.js, you can do this:

const { events } = require("brigadier");

events.on("my_event", (e, project) => {
  console.log("Hello!");
});

You can trigger any event this way. Note, however, that some events will expect certain data in the e.payload. The expectations are entirely related to the brigade.js file, though. Brigade itself does not care about the payload.