kr00lix/gen_worker

Generic Worker behavior that helps to run task at a specific time with a specified frequency.

GenWorker

Generic Worker behavior that helps to run task at a specific time with a specified frequency.

Installation and usage

It's available in Hex, the package can be installed as:

1. Add gen_worker to your list of dependencies in mix.exs:

def deps do
  [
    {:gen_worker, ">= 0.0.1"}
  ]
end

Then run mix deps.get to get the package.

1. Define your business logic:

defmodule MyWorker do
  use GenWorker, run_at: [hour: 13, minute: 59], run_each: [days: 1]

  def run do
    IO.puts "MyWorker run every day at 13:59"
  end
end

3. Add it to the application supervision tree:

def start(_type, _args) do
  import Supervisor.Spec, warn: false

  children = [
    worker(MyWorker, [])
    # ...
  ]

  opts = [strategy: :one_for_one, name: MyApp.Supervisor]
  Supervisor.start_link(children, opts)
end

Documentation can be found at https://hexdocs.pm/gen_worker.

Supported options

run_at – keyword list with integers values. Supported keys: :year, :month, :day, :hour, :minute, :second, :microsecond.

Or you can use map for multiple runs:

use GenWorker, run_at: %{"some_key" => [hour: 13, minute: 59], "other_key" => [hour: 14, minute: 00]}, run_each: [days: 1]

run_each - keyword list with integers values. Supported keys: :years, :months, :weeks, :days, :hours, :minutes, :seconds, :milliseconds. Default: [days: 1].

timezone - valid timezone. Default: :utc.

Configuration

You can define callbacks to all workers:

• init -> calls on initializing worker
• before -> calls each time before worker task starts
• finally -> calls each time on the end worker task

For exampLe it could be used in the tests test_helper.exs

  GenWorker.configure(fn c ->
    c.init(fn _module, _args ->
      :ok = Ecto.Adapters.SQL.Sandbox.checkout(App.Repo)
      Ecto.Adapters.SQL.Sandbox.mode(Repo, {:shared, self()})
      :ok
    end)
  end)

License

This software is licensed under the MIT license.

gen_worker's Issues

Server timezone not using

Hi!
My server timezone is Europe/Moscow. But i can not set this for Timex
Timex.now() return date without timezone

After update cannot run if time in past

Hi!
I have a module:

defmodule Instruments.CacheUpdater do
  @moduledoc false
  alias Helpers.RedmineApi
  use GenWorker,
      run_at: [minute: 0],
      run_each: [
        minutes: 30
      ],
      timezone: "Europe/Moscow"

  def run(_params) do
    #do actions
  end
end

on run:

[debug] GenWorker: Init worker with state: %GenWorker.State{caller: Instruments.CacheUpdater, last_called_at: nil, run_at: [minute: 0], run_each: [minutes: 30], timezone: "Europe/Moscow", worker_args: {:restart, :permanent}}
[debug] GenWorker run worker after -960000 msec
** (Mix) Could not start application telegrm: Telegrm.Application.start(:normal, []) returned an error: shutdown: failed to start child: Instruments.CacheUpdater
    ** (EXIT) an exception was raised:
        ** (ArgumentError) argument error
            :erlang.send_after(-960000, #PID<0.615.0>, :run_work)
            lib/gen_worker/server.ex:46: GenWorker.Server.schedule_work/1
            lib/gen_worker/server.ex:11: GenWorker.Server.init/1
            (stdlib) gen_server.erl:365: :gen_server.init_it/2
            (stdlib) gen_server.erl:333: :gen_server.init_it/6
            (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3

before update i simply not use run_at parameter run_at: [],, but now i cant do this.