Crontab Resource

Implements a resource that reports new versions when the current time matches the crontab expression

Update your pipeline

Update your pipeline to include this new declaration of resource types. See the example pipeline yml snippet below or the Concourse docs for more details here.

---
resource_types:
- name: cron-resource
  type: docker-image
  source:
    repository: cftoolsmiths/cron-resource

resources:
  - name: 10-min-trigger
    type: cron-resource
    source:
      expression: "*/10 * * * *"
      location: "America/New_York"
      fire_immediately: true

Source Configuration

• expression: Required. The crontab expression:

  field	allowed values
  minute	0-59
  hour	0-23
  day of month	1-31
  month	1-12 (or names, see below)
  day of week	0-7 (0 or 7 is Sun, or use names)

  e.g.

  0 23 * * 1-5 # Run at 11:00pm from Monday to Friday

• location: Optional. Defaults to UTC. Accepts any timezone that can be parsed by https://godoc.org/time#LoadLocation

  e.g.

  America/New_York

  America/Vancouver

• fire_immediately: Optional. Defaults to false. Immediately triggers the resource the first time it is checked.

Behavior

check: Report the current time.

Returns time.Now() as the version only if a minute since we last fired matches the crontab expression. The first time the script runs it will fire if a minute in the last hour matches the crontab expression.

Parameters

None.

in: Report the given time

If triggered by check, returns the original version as the resulting version.

Parameters

1. Output directory. The directory where the in script will store the requested version

out: Not implemented.

Developer Notes

Building the jobs

To build the resource's go binaries, run the following command from within the cron-resource directory:

docker run -v "$PWD":/go/src/github.com/pivotal-cf-experimental/cron-resource/ \
           -it golang:1.7 \
           /bin/bash /go/src/github.com/pivotal-cf-experimental/cron-resource/build_in_docker_container.sh

You should see two new binaries named built-in and built-check.

Testing the go binaries

Start an interactive session of your docker container to run the binaries:

docker run -v "$PWD":/go/src/github.com/pivotal-cf-experimental/cron-resource/ \
           -it golang:1.7 \
           /bin/sh

Within the interactive session:

cd /go/src/github.com/pivotal-cf-experimental/cron-resource/
./built-check

It looks like it hangs, but it's waiting for you to enter some JSON:

{"source":{"expression":"* * * * *","location":"America/New_York"} } # Paste this in after running ./built-check
[{"time":"2016-08-19T10:15:27.183011117-04:00"}] # This is the successful output
>>>>>>> Updates README with instructions on how to use Concourse's resource types, Adds developer notes.