Locally run Docker container unable to make connection to remote MySQL database - mysql

Question

I am trying to develop a micro service that gets information from a remote database but when I run the container it fails to make a connection to that database.
The container is running locally (I'm still developing it) and the database is hosted in AWS RDS Aurora MySQL.
The database is in use on multiple production websites using the same user I'm trying to use in the container. The user has full permission to the database and my local PHPMyAdmin connects to the database using that same user and I've had no trouble managing the db with it.
The problem is that the database connection in the container fails with an Access denied error.
The database user is setup as dbuser#% yet the error says:
Access denied for user 'dbuser'#'[my public ip]' (using password:
YES).
I attempted to add another account for dbuser#[my public ip] and gave it the same permissions as the wildcard host account and that makes no difference.
As another test I added a curl call inside the container to load an external page to make sure it can make external connections and that succeeds. It's just the db connection failure that makes no sense.
My dockerfile looks like this:
FROM php:7.2-apache
RUN apt-get update
RUN docker-php-ext-install mysqli pdo pdo_mysql
RUN a2enmod rewrite
I'm hoping someone has come across this and/or knows what I'm missing here.
Thanks in advance!
Some more info:
I'm using Docker for Windows and docker-compose to run my container. My docker-compose.yml file looks like:
version: "3"
services:
web:
image: repository/container:latest
volumes:
- ./src:/var/www/html
deploy:
replicas: 5
resources:
limits:
cpus: "0.1"
memory: 50M
restart_policy:
condition: on-failure
ports:
- "80:80"
networks:
- inv
networks:
inv:

Answer 1

Starting the container with docker run --network host ... will make the container share the network stack of the host. That should solve the problem.

Answer 2

I ended up fixing this by copying the original connection code from my API and replacing the connection code in my container with it.
I commented out the broken code and compared the two but see no difference. No quote marks in the host string, no typos, nothing that makes sense.
The only difference is the way I'm setting the variables that build the host string. The values of those variables are the same so it really doesn't make sense.
Regardless, doing this fixed it.