cftoolsmiths/cron-resource repository overview

⁠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.