i have 3 container (php-fpm, nginx, postgresql) for my laravel app, i execute command php artisan schema:dump on php-fpm container and I found error pg_dump not found
I have had similar issue but with mysql. What solved it for me was an installation of mysql-client inside the container in which I was trying to execute php artisan schema:dump command (I have added RUN apt-get install -y mysql-client inside my Dockerfile, then I have rebuilt all the containers). I think that you need to do similar thing, e.g. RUN apt-get install -y postgresql-client inside your Dockerfile.