Docker: Connection timeout when connecting to database container - symfony

Question

I'm having an issue with my php container not connecting to my database container.
My docker-compose.yml :
version: "2"
volumes:
# this is the mysql data volume we are going to host the data inside
dev_mysql_data:
# This volume is used for elasticsearch
dev_elastic_search:
networks:
mp_pixel:
driver: bridge
ipam:
driver: default
config:
- subnet: 172.20.0.0/16
services:
# database container for local development purposes
dev_database:
image: mysql:5.6
networks:
mp_pixel:
aliases:
- database
ports:
# port 3304 (external) is for use on your desktop sql client
# port 3306 (internal) is for use inside your application code
- 3304:3306
volumes:
# mount the mysql_data docker volume to host the local development database
- dev_mysql_data:/var/lib/mysql
# the provision file helps when trying to use the provision script to clone databases
- ./provision.cnf:/provision.cnf
environment:
MYSQL_ROOT_PASSWORD: pixel
# This is the local development version of the nginx container
dev_nginx:
image: mp-pixel-nginx:latest
build: ./nginx
ports:
- '80:80'
- '443:443'
networks:
mp_pixel:
aliases:
- nginx
depends_on:
- dev_phpfpm
volumes_from:
- dev_phpfpm
environment:
- VIRTUAL_HOST=~^(mp-pixel|mp-location|mp-feedback|mp-user|mp-phone|mp-loancalculator|mp-seo|mp-media|mp-listing|mp-development|mp-kpi|mp-newsletter|mp-auth|mp-worker|mp-search)-ph-dev.pixel.local
# This is the local development version of the phpfpm container
dev_phpfpm:
image: mp-pixel-phpfpm:latest
build:
context: ./
args:
# this build might fail, if so, run in a terminal: export SSH_KEY=$(cat ~/.ssh/id_rsa)
- SSH_KEY=$SSH_KEY
networks:
mp_pixel:
aliases:
- phpfpm
depends_on:
- dev_database
volumes:
# we override the images /www directory with the code from the live machine
- ./:/www
env_file:
# inside this file, are the shared database secrets such as username/password
- ./env/common
- ./env/dev
dev_elasticsearch:
image: docker.elastic.co/elasticsearch/elasticsearch:5.3.3
networks:
mp_pixel:
aliases:
- elasticsearch
ulimits:
memlock:
soft: -1
hard: -1
nofile:
soft: 65536
hard: 65536
mem_limit: 1g
cap_add:
- IPC_LOCK
volumes:
- dev_elastic_search:/usr/share/elasticsearch/data
ports:
- 9200:9200
environment:
- cluster.name=dev-elasticsearch-pixel
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
- "xpack.security.enabled=false"
I run it with docker-compose up and the php logs show
An exception occured in driver: SQLSTATE[HY000] [2002] Connection timed out
I try to access the database container with docker exec, and I can confirm that I have the right credentials.
What could be the problem?

Answer 1

When your containers are up, did you already try to connect to the database with a tool like Sequel Pro? Maybe the database is just not initialized and because of this, the connection from the php container can't be established? You tried to access the db container but not the database itself.
Additionally you could add some more environment variables to the database section of your docker-compose.yml
environment:
- MYSQL_ALLOW_EMPTY_PASSWORD=yes
- MYSQL_DATABASE=databasename
- MYSQL_USER=databaseuser
- MYSQL_PASSWORD=databasepassword
Hope that helps