Elastic beanstalk docker - map symfony logs to S3

In config.yml

monolog:
    handlers:
        main:
            type:         fingers_crossed
            action_level: error
            buffer_size:  200
            handler:      nested
        nested:
            type:  stream
            path:  %log_dir%/moonlight_%kernel.environment%.log
            level: debug

Make log_dir in parameter.yml to be /var/log/nginx or anywhere you want. 

Create a file called Dockerrun.aws.json

{

  "AWSEBDockerrunVersion": "1",

  "Ports": [

    {

      "ContainerPort": "80"

    }

  ],

  "Logging": "/var/log/nginx"

}

The logging entry above needs to be the same as log_dir you set in parameter.log.

In Elastic Beanstalk settings, click on Configuration on the left side, then software configuration.

Check "Enable log file rotation to Amazon S3. If checked, service logs are published to S3."

If you are using a custom IAM, you will need to grant read and write permissions to S3:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "Stmt1435793320000",
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:GetObjectVersion",
                "s3:ListBucket",
                "s3:ListBucketVersions"
            ],
            "Resource": [
                "arn:aws:s3:::elasticbeanstalk-*/resources/environments/logs/*"
            ]
        }
    ]
}

Log rotations happen about every 15 mins. You can search the s3 directory elasticbeanstalk-*/resources/environments/logs/* for logs.