I was surprised to see how it is to get the ElasticBeanstalk (EB) environment name from the EB instance. I wrote this quickly to fetch the name so I can run a switch on that, and have different configurations on different environments running crons.

ElasticBeanstalkGetEnvironmentName.php

<?php

$instanceId = file_get_contents('http://169.254.169.254/latest/meta-data/instance-id');

//I'd prefer to use the SDK here
exec('aws ec2 describe-instances --filters "Name=instance-id,Values='.$instanceId.'"',$results);
$instances = json_decode(implode(PHP_EOL,$results),true);

//fingers crossed
$tags = $instances['Reservations'][0]['Instances'][0]['Tags'];
$keyMatch = 'elasticbeanstalk:environment-name';
$environment = null;
foreach($tags as $tag) {
        if($tag['Key'] == $keyMatch){
                $environment = $tag['Value'];
        }
}

echo $environment;