Laravel 6 - 12.x Task Scheduler with Elastic Beanstalk
Ensure one instance in an Elastic Beanstalk environment is running Laravel's Scheduler, (*1)
A common problem many people have encountered with Amazon's Elastic Beanstalk is maintaining a single instance in an environment that runs Laravel's Task Scheduler. Difficulties arise because auto-scaling does not guarantee any instance is run indefinitely and there are no "master-slave" relationships within an environment to differentiate one instance from the rest., (*2)
Although Amazon has provided a solution it involves setting up a worker tier and then, potentially, creating new routes/methods for implementing the tasks that need to be run. Yuck!, (*3)
This package provides a simple, zero-setup solution for maintaining one instance within an Elastic Beanstalk environment that runs the Task Scheduler., (*4)
Amazon Linux 1 is deprecated and Amazon Linux 2023 is recommended
Amazon Linux 1 (AL1) is already retired, even Amazon Linux 2 (AL2) will soon going to be unsupported too, so it's recommended to migrate to use Amazon Linux 2023 (AL2023)
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.migration-al.html
Starts from this release will only support AL2023, please use previous releases for use in AL2, with this release will also drop support for Laravel 5 (PHP 7) since EB only support starting from PHP 8.1, (*5)
How Does It Work?
Glad you asked! The below process is completely automated and only requires that you publish the .platform folder to the root of your application., (*6)
1. Use Elastic Beanstalk's Advanced Configuration to run CRON setup commands
EB applications since AL2 can contain platform hooks that provides advanced configuration for an EB environment, called .platform., (*7)
This package provides a configuration file that runs two commands on deployment (every instance initialization) that setup the conditions needed to run the Task Scheduler on one instance:, (*8)
2. Run system:start:leaderselection
This is the first command that is run on deployment. It configures the instance's Cron to run Leader Selection at a configured interval (default = 5 minutes), (*9)
This is the Leader Selection command. It does the following:, (*10)
- Get the Id of the Instance this deployment is running on
- Get the
EnvironmentName of this Instance. (When running in an EB environment all EC2 instances have the same EnvironmentName)
- Get all running EC2 instances with that
EnvironmentName
- Find the earliest launched instance
If this instance is the earliest launched then it is deemed the Leader and runs system:start:cron, (*11)
4. Run system:start:cron
This command is run only if the current instance running Leader Selection is the Leader. It inserts another entry in the instance's Cron to run Laravel's Scheduler., (*12)
That's it!
Now only one instance, the earliest launched, will have the scheduler inserted into its Cron. If that instance is terminated by auto-scaling a new Leader will be chosen within 5 minutes (or the configured interval) from the remaining running instances., (*13)
Installation
Require this package, (*14)
composer require "foxxmd/laravel-elasticbeanstalk-cron"
Then, publish the .platform folder and configuration file, (*15)
php artisan vendor:publish --tag=ebcron
Don't forget to add +x permission to the EB Platform Hooks scripts (no longer required for Amazon Linux platform that released on or after April 29, 2022), (*16)
find .platform -type f -iname "*.sh" -exec chmod +x {} +
Configuration
In order for Leader Selection to run a few environmental variables must be present:, (*17)
-
USE_CRON = true -- Must be set in order for Leader Selection to occur. (This can be used to prevent Selection from occurring on undesired environments IE Workers, etc.)
-
AWS_ACCESS_KEY_ID -- Needed for read-only access to EC2 client
-
AWS_SECRET_ACCESS_KEY -- Needed for read-only access to EC2 client
-
AWS_REGION -- Sets which AWS region when looking using the EC2 client, defaults to
us-east-1 if not set.
These can be included in your .env or, for EB, in the environment's configuration section., (*18)
Contributing
Make a PR for some extra functionality and I will happily accept it :), (*19)
License
This package is licensed under the MIT license., (*20)
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FoxxMD