AWS Elastic BeanStalk .ebextensions Package Manager for Ubuntu

The cleanest way I found is to use a .ebextensions config file in my project archive:

Sample .ebextensions/project.config file:

files:
  "/etc/php.d/project.ini" :
    mode: "000644"
    owner: root
    group: root
    content: |
      upload_max_filesize = 64M
      post_max_size = 64M

When the application version is deployed, this will write a custom config file in the php.d directory, that will override any php.ini setting.

If you're using NGINX or other proxy server, it may be related to it's client_max_body_size directive. To fix it create folder .ebextensions in app root, and a file .ebextensions/01_nginx.config. Then tell build script to add this directive while building your environment, adding this to your created .ebextensions/01_nginx.config:

container_commands:
  01_reload_nginx:
    command: "service nginx reload"
files:
    "/etc/nginx/conf.d/proxy.conf":
      mode: "000755"
      owner: root
      group: root
      content: |
        client_max_body_size 25M;

Commit your folder to git, if you're using it. Then eb deploy, cross fingers and try to upload your 6MB PDF.

However, according to my experience, sometimes you have to completely rebuild entire environment to make it work.