crony

README

Crony 🕠

• All the flexibility and power of Cron as a Service.
• Simple REST protocol, integrating with a web application in a easy and straightforward way.
• No more wasting time building and managing scheduling infrastructure.

Basic Concepts

Crony works by calling back to your application via HTTP GET according to a schedule constructed by you or your application.

Setup

Env vars

export DATASTORE_URL="postgresql://postgres@localhost/crony?sslmode=disable"
export PORT=3000

mkdir -p $GOPATH/src/github.com/rafaeljesus
cd $GOPATH/src/github.com/rafaeljesus
git clone https://github.com/rafaeljesus/crony.git
cd crony
make all

Running server

./dist/crony
# => Starting Crony at port 3000

Authentication

This API does not ship with an authentication layer. You should not expose the API to the Internet. This API should be deployed behind a firewall, only your application servers should be allowed to send requests to the API.

API Endpoints

• GET /health - Get application health
• GET /events - Get a list of scheduled events
• POST /events - Create a event
• GET /events/:id - Get a single event
• DELETE /events/:id - Delete a event
• PATCH /events/:id - Update a event

API Documentation

GET /events

Get a list of available events.

• Method: GET
• Endpoint: /events
• Responses:
  • 200 OK

  [
     {
        "id":1,
        "url":"your-api/job",
        "expression": "0 5 * * * *",
        "status": "active",
        "max_retries": 2,
        "retry_timeout": 3,
        "created_at": "2016-12-10T14:02:37.064641296-02:00",
        "updated_at": "2016-12-10T14:02:37.064641296-02:00"
     }
  ]
  

  • id is the id of the event.
  • url: is the url callback to called.
  • expression: is cron expression format.
  • status: tell if the event is active or paused.
  • max_retries: the number of attempts to send event.
  • retry_timeout: is the retry timeout.

POST /events

Create a new event.

• Method: POST

• Endpoint: /events

• Input: The Content-Type HTTP header should be set to application/json

  {
    "url":"your-api/job",
    "expression": "0 5 * * * *",
    "status": "active",
    "max_retries": 2,
    "retry_timeout": 3,
  }
  

• Responses:

  • 201 Created

  {
    "url":"your-api/job",
    "expression": "0 5 * * * *",
    "status": "active",
    "max_retries": 2,
    "retry_timeout": 3,
    "updated_at": "2016-12-10T14:02:37.064641296-02:00",
    "created_at": "2016-12-10T14:02:37.064641296-02:00"
  }
  

  • 422 Unprocessable entity:

  {
    "status":"invalid_event",
    "message":"<reason>"
  }
  

  • 400 Bad Request

  {
    "status":"invalid_json",
    "message":"Cannot decode the given JSON payload"
  }
  

  Common reasons:

  • the event job already scheduled. The message will be Event already exists
  • the expression must be crontab format.
  • the retry must be between 0 and 10
  • the status must be active or incative

GET /events/:id

Get a specific event.

• Method: GET
• Endpoint: /events/:id
• Responses:
  • 200 OK

  {
    "url":"your-api/job",
    "expression": "0 5 * * * *",
    "status": "active",
    "max_retries": 2,
    "retry_timeout": 3,
    "updated_at": "2016-12-10T14:02:37.064641296-02:00",
    "created_at": "2016-12-10T14:02:37.064641296-02:00"
  }
  

  • 404 Not Found

  {
    "status":"event_not_found",
    "message":"The event was not found"
  }
  

DELETE /events/:id

Remove a scheduled event.

• Method: DELETE
• Endpoint: /events/:id
• Responses:
  • 200 OK

  {
    "status":"event_deleted",
    "message":"The event was successfully deleted"
  }
  

  • 404 Not Found

  {
    "status":"event_not_found",
    "message":"The event was not found"
  }
  

PATCH /events/:id

Update a event.

• Method: PATCH

• Endpoint: /events/:id

• Input: The Content-Type HTTP header should be set to application/json

  {
    "expression": "0 2 * * * *"
  }
  

• Responses:

  • 200 OK

  {
    "url":"your-api/job",
    "expression": "0 2 * * * *",
    "status": "active",
    "max_retries": 2,
    "retry_timeout": 3,
    "updated_at": "2016-12-10T14:02:37.064641296-02:00",
    "created_at": "2016-12-10T14:02:37.064641296-02:00"
  }
  

  • 404 Not Found

  {
    "status":"event_not_found",
    "message":"The event was not found"
  }
  

  • 422 Unprocessable entity:

  {
    "status":"invalid_json",
    "message":"Cannot decode the given JSON payload"
  }
  

  • 400 Bad Request

  {
    "status":"invalid_event",
    "message":"<reason>"
  }
  

Cron Format

The cron expression format allowed is:

Field name	Mandatory?	Allowed values	Allowed special characters
Seconds	Yes	0-59	* / , -
Minutes	Yes	0-59	* / , -
Hours	Yes	0-23	* / , -
Day of month	Yes	1-31	* / , - ?
Month	Yes	1-12 or JAN-DEC	* / , -
Day of week	Yes	0-6 or SUN-SAT	* / , - ?
more details about expression format here

Contributing

• Fork it
• Create your feature branch (git checkout -b my-new-feature)
• Commit your changes (git commit -am 'Add some feature')
• Push to the branch (git push origin my-new-feature)
• Create new Pull Request

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