상황

해결

Folder structure (.platform/nginx/conf.d/proxy.conf)

.platform/
         nginx/
              conf.d/
                    proxy.conf
         00_myconf.config

Content of File 1 - proxy.conf (Inside .platform/nginx/conf.d/ folder)

client_max_body_size 50M;

Content of File 2 - 00_myconf.config (Inside .platform/ folder)

container_commands:
  01_reload_nginx:
    command: "service nginx reload"

참고

https://stackoverflow.com/questions/18908426/increasing-client-max-body-size-in-nginx-conf-on-aws-elastic-beanstalk 의 Jijo Cleetus 답변