Running Dockerfile with CMD supervisor in App Platform

Question

I have a project with a Dockerfile that roughly has the following: FROM php:7.2-apache # supervisor installation && # create directory for child images to store configuration in RUN apt-get -y install supervisor && \ mkdir -p /var/log/supervisor && \ mkdir -p /etc/supervisor/conf.d # supervisor configurations ADD /.docker/conf/supervisor/conf.d/apache.conf /etc/supervisor/conf.d/apache.conf ADD /.docker/conf/supervisor/conf.d/Emails.conf /etc/supervisor/conf.d/Emails.conf # Docker will start only supervisord CMD ["/usr/bin/supervisord", "-c", "/etc/supervisor/supervisor.conf"] apache.conf is supervisor keeping apache alive and Emails.conf is Laravel’s queue:work command kept alive. However my app in App Platform fails with: 2021-12-03T10:31:17.440161328Z Unlinking stale socket /var/run/supervisor.sock2021-12-03T10:31:17.741289162Z Error: Another program is already listening on a port that one of our HTTP servers is configured to use. Shut this program down first before starting supervisord.2021-12-03T10:31:17.741327485Z For help, use /usr/bin/supervisord -h The error occurs only in App Platform, Docker builds the container OK.

JWhite001 · Answer

Hi there, try debugging the code, it has some silly errors. Thank you.

Bobby · Answer

Hi there,

It seems like that there is a conflict over port usage. The message “Another program is already listening on a port that one of our HTTP servers is configured to use” indicates that supervisord is trying to bind to a port already in use, likely by the built-in Apache server in the php:7.2-apache image.

You could check that the supervisor configuration files (apache.conf and Emails.conf) do not specify services that bind to ports already in use. Specifically, check if the Apache configuration under supervisor is not trying to start another instance of Apache that’s already running by default in the php:7.2-apache image.

On another note, a quick update here, the App Platform now supports this via Aptfile which would allow you to use the native PHP buildpack and install custom dependenices:

https://docs.digitalocean.com/products/app-platform/reference/buildpacks/aptfile/

App Platform looks for a file named Aptfile (no file extension) to detect an application requiring system packages. If this file is detected, the heroku-buildpack-apt buildpack is used to install any packages listed in the Aptfile during the build process.

The following example Aptfile declares three system packages to install: