Laravel Docker Container not connecting to local mysql - mysql

Question

I have an issue connecting to mysql running in the local machine in my DockerFile i have mentioned
FROM php:7
RUN apt-get update -y && apt-get install -y openssl zip unzip git
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
RUN docker-php-ext-install pdo mbstring pdo_mysql
WORKDIR /home
COPY . /home
RUN composer install --ignore-platform-reqs
CMD php artisan serve --host=0.0.0.0 --port=8081
EXPOSE 8081
and this in my .env configuration
DB_HOST=localhost
DB_DATABASE=databasename
DB_USERNAME=root
DB_PASSWORD=testpassword
I have very less clue about where it is failing. Do i need to install mysql for Docker container also?

Answer 1

A much simpler solution (for Mac OSX & Docker for Windows) is to replace the host address from localhost
to host.docker.internal
DB_HOST=host.docker.internal
DB_DATABASE=databasename
DB_USERNAME=root
DB_PASSWORD=testpassword
Basically the DNS namehost.docker.internal will resolves to the internal IP address used by the host.
NB: If you have changed your address to host.docker.internal but you still receive connection refused error, it’s most probably because MySQL is currently configured to only listen to the local network.
To resolve that, please update the value of the bind_address to 0.0.0.0 in your my.cnf configuration file.

Answer 2

you are trying to connect to mysql in localhost, which is (surprisingly) the reference to the local host. since its a relative address, inside the container it is being resolved as the container own address, and no mysql is awaiting you there...
so to solve it - just give it your real host ip instead of localhost or 127.0.0.1.
step 1 - fix .env file:
DB_HOST=<your_host_ip> #run `ifconfig` and look for your ip on `docker0` network
DB_DATABASE=databasename
DB_USERNAME=laravel_server #not root, since we are going to allow this user remote access.
DB_PASSWORD=testpassword
step 2 - create dedicated user:
open your mysql: mysql -u root -p, give your root password, and run the following:
CREATE USER 'laravel_server'#'%' IDENTIFIED BY 'testpassword';
GRANT ALL PRIVILEGES ON databasename.* TO 'laravel_server'#'%';
FLUSH PRIVILEGES;
we created the user and gave it the permissions.
step 3 - open mysql to remote access:
we have to make it listening on all interfaces and not just localhost and therefore we run:
sudo sed 's/.*bind-address.*/bind-address=0.0.0.0/' /etc/mysql/mysql.conf.d/mysqld.cnf
(you will be prompted for password. this command is just replacing the line in mysql configuration file)
step 4 - updating:
in the project directory: php artisan config:cache
service mysql restart
then docker build and run a new container again. it should work for you.

Answer 3

I see two options -
Use the private IP of your docker host i.e where mysql server is running.
Use the host network mode while running container in case you want to use localhost.
docker container --net=host ...

Answer 4

In my case (Ubuntu 20.04 Desktop), I had MariaDB already running and using port 3306. So when the app inside the docker container was trying to start MySQL that was inside the container it failed because it was trying to listen to an already used port. I switched off the already-running MariaDB using the command below :
sudo systemctl stop mariadb.service
Then tried starting the docker app. It ran successfully because port 3306 was now free and used by MySQL inside the container. But since I intend to use both of them, a much more permanent solution would be to configure either of the Database systems i.e the one inside the docker container or the one outside the docker container to use a different port other than the default 3306.