Create the schedule API

[deviantony]

Related to #2183

[chiptus]

Backend

Introduction of a new Schedule entity with the following fields:

• Name string
• Endpoints []EndpointId
• Schedule string
• ScriptPath string

New API handlers to manage schedules:

• /schedules (GET)
• /schedules (POST): should support two different payloads (JSON for script content / form-data for file upload)
• /schedules/:id (GET)
• /schedules/:id (PUT)
• /schedules/:id (DELETE)

Leads for a potential implementation:

• It can re-use the existing cron library to manage scheduling / job executions. When a job is trigger, endpoints that are considered as Down should be ignored for now.
• Scripts can be stored on disk in /data/schedules/:scheduleId
• When targeting a Swarm + agent environment, all node names in the cluster can be retrieved to execute the job on each node in the cluster
• Each container created as a part of a schedule should have the io.portainer.schedule.ID label set to scheduleID.

[chiptus]

Implementation details:

1. Schedule service (docker package)

This is the interface for handling actions on schedules.

It will provide the following methods:

Schedules(): []Schedules
Schedule(scheduleId int): returns the schedule object
CreateSchedule(name string, endpoints [], schedule string, script []byte) : int
UpdateSchedule(scheduleId int, name string, endpoints [], schedule string, script []byte)
DeleteSchedule(scheduleId int)

2. Bolt Schedule Service

A new service inside the bolt package that is responsible to add, remove, update, get schedules in the db

3. Cron Schedule Service

Responsible of scheduling, removing and updating and running tasks schedules in cron

[deviantony]

@chiptus I think that the schedule service should be located in the cron package instead and leverage the JobService introduced via #2361

[deviantony]

@chiptus I think that the schedule service should be located in the cron package instead and leverage the JobService introduced via #2361

[deviantony]

@chiptus I think that the schedule service should be located in the cron package instead and leverage the JobService introduced via #2361