phpgt/cron

Run scripts or static functions at regular intervals.

cron's Issues

Post-cron command

Allow a configuration option to set a particular command to run after each cron task has completed.

This will be totally optional, but will allow for monitoring of cron's health without having to implement any additional services.

Improve CLI

1. Standardise namespace
2. Use proper stream
3. Type improvements

Sub-minute syntax

This is non-standard, but it would be nice to be able to schedule a script for every 10 seconds. At the moment, * * * * * is equal to once per minute, which is currently the most frequent cron setting.

Setting */10 * * * * will trigger every 10 minutes.

My proposed syntax for every 10 seconds:

*:10 * * * *

The colon is obviously different than the slash, and is already used in time formats, so it shouldn't be too difficult to understand what this does without reading the docs.

Explain crons in crontab

An --explain flag would be brilliant. It would list out the cron jobs you have in the crontab file and explain when they will run.

Example output:

0 0 * * FRI /backup		At 12:00 AM, only on Friday
0 * * * * /clean-cache		Every hour
05 01 * * SUN#1			At 01:05 AM, on the first Sunday of the month

Test "validate" cli command

The validate command has been created to output OK on no errors and pass the original parse exception on error. There are currently no tests in place for this.

When running via `gt run`, comments cause syntax error

This is a weird one, but very reproducable by running gt create (which puts a blank crontab) and then gt run.

@background and @start

Linux crontab supports replacing the date/time columns with @reboot to indicate that the script should be run once on reboot.

As a new feature, @background can be used to indicate that the script should be run forever in the background (waiting for the process to finish before starting again).

@start can be used to indicate that the script should be run once at the start of the server starting.

Ensure tasks are running in their own process

This may already be the case, but it's worth double checking and putting in the documentation.

The way the Linux cron system works is that all tasks are run concurrently. This needs to be the case for this project too.

Imagine there are some background scripts that take 20 seconds to run. Put them in on the crontab to run every minute, and they should be completed concurrently within their 20 second execution time... however if they are not run concurrently, more than three scripts will overlap into the next minute, and things will catch fire rather quickly.

Comments in crontab

Dependabot

Dependabot needs to be tamed, as per PhpGt/WebEngine#568

Automatically create and install .service file

A bin file in the vendor/bin directory should be created that allows creating and installing the relevant .service file for the systemd process to call the correct cron processing script.

Test calling static function that doesn't exist

Error if crontab file doesn't exist

It's fine to not have a crontab file. There shouldn't be an error.

Specify what jobs have just run

Just ran 1 job, next job at: 21:16:00.

It would be nicer if it said "Just ran 1 job (script/cache/refresh)"

The "next job at" can be on its own line.

Watching a cron shows incorrect time after first run

On the second and subsequent task runs, the "next job at" time is incorrectly showing the first job's time.

Run all cron tasks at start

Pass a flag such as --all to run all of the cron tasks instantly when cron is called. Useful for local development.

Test calling script that doesn't exist

Cron top-level directory with named scripts

It would be nice to be able to treat cron scripts in the same way as we do Page Logic files, almost as if (or maybe completely as if) the scripts are being routed.

Inside the crontab file, we could have something like the following:

0 5 * * * /cache?type=db&mode=daily

This would be triggered at 0500 every day, and it makes sense to store this script in the cron/cache.php file.

Inside the file, it can behave completely like any other go function:

<?php
use Gt\Input\Input;

function go(Input $input, Database $db):void {
  if($input->getString("type") === "db") {
    $db->clean(); // or whatever...
  }
}