PHP Test

# Docker:PHP/PDO + MySQL.. How to? Photo by [fabio](https://unsplash.com/@fabioha?utm_source=medium&utm_medium=referral) on [Unsplash](https://unsplash.com?utm_source=medium&utm_medium=referral) ## Context A _PHP_ server and a _MySQL_ database. This is a very common setup. **You’ve to create a PHP script that interact with that database**, but you’ve no access to the server because only script from localhost works due to firewall security restriction for example. **Problem:** To test your script you’ve to open a FTP client, upload the `.php` script to the server and test it. Every time the php file changes you’ve to repeat this procedure, not considering that make attempts in production is a very bad practice. ## Solution: Docker > _Docker_ can come to rescue as he let the developer to create in a few steps an environment similar to the production one. **This even allow developer testing their code in a local environment without fear to make mistakes!** There are ready to use containers for [PHP](https://hub.docker.com/_/php) and [MySQL](https://hub.docker.com/_/mysql), many tutorial and online resources that tell how to put them together with and without *docker-compose.* I found [this one](https://alysivji.github.io/php-mysql-docker-containers.html) very useful using docker-compose, and [this one](https://severalnines.com/database-blog/mysql-docker-containers-understanding-basics) not using it, but **I struggled trying to use PHP+PDO to simply open a connection with my MySQL database only reading these articles**. The reason why I’d use PDO is that MySQLi extension has been deprecated, as [W3C says](https://www.w3schools.com/php/php_mysql_connect.asp). ## Environment configuration problems (the reason why I’m writing this article): Communication from Host to MySQL container worked, but communication from PHP container to MySQL container not. > _docker-compose_ and an adequate variable assignment in the `.php` file are the keys to solve the problem Here’s my `docker-compose`: ```yml version: '3' services: database: image: mysql:5.7 environment: MYSQL_ROOT_PASSWORD: 123 MYSQL_DATABASE: stt_db MYSQL_USER: devuser MYSQL_PASSWORD: 123 ports: - "9906:3306" web: build: . container_name: php_web depends_on: - database volumes: - ./local/:/var/www/html/ ports: - "8100:80" stdin_open: true tty: true ``` We can see that `db` image has left as is (`mysql:5.7`), but not the web one, since we’ve to install PDO extension to the base PHP image. Note that both containers are exposed to host by ports 8100 for _PHP_ container and by 9906 port for _MySQL_ database: in this way we can connect to it through [mysql-cli](https://dev.mysql.com/doc/refman/8.0/en/mysql.html) from host terminal with a command like the one below: ```sh mysql -uroot -p123 -h127.0.0.1 -P9906 ``` where `-P` stands for “Port” and must match with the hots-exposed one defined in `docker-compose`. `-p` stands for “password” and `-u` stands for “user”. ### Below the `Dockerfile` ```dockerfile FROM php:7.4-cli COPY ./local /usr/src/dst_folder WORKDIR /usr/src/dst_folder RUN docker-php-ext-install pdo pdo_mysql ``` last line install the required extensions. ## Let's put things together At the end, this is my **MySQL PHP connection script**: ```php PHP Test setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); echo "Connected succesfully"; } catch(PDOException $e){ echo "Connection failed: " . $e -> getMessage(); } ?> ``` note two important things: * `$servername` is set to the **mysql service name** in `docker-compose.yml` since docker-compose allow containers declared inside `docker-compose.yml` to communicate each other by service name. No worries about IP address * `$port` is set to the in-network port where “in-network” is the one created automatically by docker-compose when run by `docker-compose up` * browse [http://localhost:8100](http://localhost:8100) and you’ll se the message: “Connected succesfully” ![An happy runner](https://cdn.hashnode.com/res/hashnode/image/upload/v1637873012996/Wy3ackYcV.jpeg) Photo by [Wesley Eland](https://unsplash.com/@wesleyeland?utm_source=medium&utm_medium=referral) on [Unsplash](https://unsplash.com?utm_source=medium&utm_medium=referral) ### Thanks for reading :)