cannot connect mysql and php - php

Question

Having this lamp docker setup (Im a sort of docker newbie):
docker-compose.yml
version: '2'
services:
webserver:
build: .
ports:
- "8080:80"
- "443:443"
volumes:
- ./:/var/www/html
links:
- db
db:
image: mysql:5.6
ports:
- "3306:3306"
volumes:
- /var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=adminpasswd
- MYSQL_DATABASE=se_racken_dev
phpmyadmin:
image: phpmyadmin/phpmyadmin:latest
ports:
- "88:80"
links:
- db:db
Dockerfile
FROM php:5.6-apache
RUN apt-get update -y && apt-get install -y libpng-dev curl libcurl4-openssl-dev
RUN docker-php-ext-install pdo pdo_mysql gd curl
RUN a2enmod rewrite
RUN service apache2 restart
Just cant get my local environment to work.
Get this error message at localhost:8088:
SQLSTATE[HY000] [2002] No such file or directory
How can I configure my docker setup to get past this connection problem?
Got some hints here:
Starting with Zend Tutorial - Zend_DB_Adapter throws Exception: "SQLSTATE[HY000] [2002] No such file or directory"
Do I need to install vim and do what they suggest in above or can I solve it in my docker files?

Answer 1

On webserver image you should define the connection values such as database's hostname,database name, username and password.
What can you can is to specify a .env file as seen in https://docs.docker.com/compose/env-file/
In your case that should be:
DB_HOSTNAME=db:/var/run/mysqld/mysqld.sock
DB_USER=root
DB_PASSWORD=somepassword
DB_NAME=se_racken_dev
Then to your Dockerfile specify:
FROM php:5.6-apache
ENV MYSQL_HOSTNAME="localhost"
ENV MYSQL_PASSWORD=""
ENV MYSQL_USERNAME="root"
ENV MYSQL_DATABASE_NAME=""
RUN apt-get update -y && apt-get install -y libpng-dev curl libcurl4-openssl-dev
RUN docker-php-ext-install pdo pdo_mysql gd curl
RUN a2enmod rewrite
RUN service apache2 restart
Then modify your docker-compose.yml like that:
version: '2'
services:
webserver:
build: .
ports:
- "8080:80"
- "443:443"
volumes:
- ./:/var/www/html
links:
- db
environment:
- MYSQL_HOSTNAME=$DB_HOSTNAME
- MYSQL_PASSWORD=$DB_USER
- MYSQL_USERNAME=$DB_PASSWORD
- MYSQL_DATABASE_NAME=$DB_NAME
db:
image: mysql:5.6
ports:
- "3306:3306"
volumes:
- /var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=$DB_PASSWORD
- MYSQL_DATABASE=$DB_NAME
phpmyadmin:
image: phpmyadmin/phpmyadmin:latest
ports:
- "88:80"
links:
- db:db
Then you can use php's getenv to retreive the values from enviromental variables you specified. eg In your case the getenv('MYSQL_DATABASE_NAME') will retreive the value "se_racken_dev" as a string. So you need to modify the database configuration file in order to retreive correctly the database connection credentials using the function mewntioned above.
A simple way to remember is whatever you specify via ENV in your dockerfile you can retreive via getenv.