Docker MySQL - can't connect from Spring Boot app to MySQL database - mysql

Question

What I'm trying to do is, connect from my spring-boot app to mysql database in Docker. Each in their own container.
But I must be having something wrong because I can't do it.
To keep it simple :
application-properties :
# URL for the mysql db
spring.datasource.url=jdbc:mysql://workaround-mysql:3308/workaround?serverTimezone=UTC&max_allowed_packet=15728640
# User name in mysql
spring.datasource.username=springuser
# Password for mysql
spring.datasource.password=admin
#Port at which application runs
server.port=8080
docker-compose for MySQL:
version: '3'
services:
workaround-mysql:
container_name: workaround-mysql
image: mysql
environment:
MYSQL_DATABASE: workaround
MYSQL_USER: springuser
MYSQL_PASSWORD: admin
MYSQL_ROOT_PASSWORD: admin
MYSQL_ROOT_HOST: '%'
ports:
- "3308:3306"
restart: always
So pretty simple right ? Database I start with docker-compose up:
All seems to be working fine so far.
Now that I have db started, to the application, this is its docker-compose.yml:
version: '3'
services:
workaround:
restart: always
# will build ./docker/workaround/Dockerfile
build: ./docker/workaround
working_dir: /workaround
volumes:
- ./:/workaround
- ~/.m2:/root/.m2
expose:
- "8080"
command: "mvn clean spring-boot:run"
For its Dockerfile I use Linux Alpine and Java.
FROM alpine:3.9
....add java...
RUN apk update
RUN apk add dos2unix --update-cache --repository http://dl-3.alpinelinux.org/alpine/edge/community/ --allow-untrusted
RUN apk add bash
RUN apk add maven
Super simple. Now let's start the application :
Unknown host, so let's try the IP then :
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' workaround-mysql
# URL for the mysql db
spring.datasource.url=jdbc:mysql://172.20.0.2:3308/workaround?serverTimezone=UTC&max_allowed_packet=15728640
Now I get timeout:
As you can see I get error. What is wrong with my setup and how to fix
this? Either I have unknown host exception or Refused to connect or connection timeout.
I have tried:
Using ip of a container in my application.properties, didn't work
Different ports for MySQL and application
Different images and versions of MySQL
Having everything in one docker compose with wait
timer for database.
Minimal setup with
https://github.com/hellokoding/hellokoding-courses/tree/master/docker-examples/dockercompose-springboot-mysql-nginx
Also resulted in communication link failure, Site was accessible but I
doubt that db was connected properly.
Notes:
I run this all on one computer I use port 3308 because I have local
MySQL db at 3306.
Here is docker ps -a
#Vusal ANSWER output :
Only thing different from code in answer I did wait for database to be ready 30 seconds
command: /bin/bash -c "sleep 30;mvn clean spring-boot:run;"

Answer 1

Try this docker-compose.yml:
version: '3'
services:
workaround-mysql:
container_name: workaround-mysql
image: mysql
environment:
MYSQL_DATABASE: workaround
MYSQL_USER: springuser
MYSQL_PASSWORD: admin
MYSQL_ROOT_PASSWORD: admin
MYSQL_ROOT_HOST: '%'
ports:
- "3308:3306"
restart: always
workaround:
depends_on:
- workaround-mysql
restart: always
# will build ./docker/workaround/Dockerfile
build: ./docker/workaround
working_dir: /workaround
volumes:
- ./:/workaround
- ~/.m2:/root/.m2
expose:
- "8080"
command: "mvn clean spring-boot:run"
And update your application.properties to use the next JDBC connection url:
spring.datasource.url=jdbc:mysql://workaround-mysql:3306/workaround?serverTimezone=UTC&max_allowed_packet=15728640
It should work when both containers in the same docker-compose file, because docker-compose creates default network for containers, so they can resolve each other by name.

Answer 2

What you haven't tried so far is running both containers on the same Docker network.
First, forget about IP addressing - using it should be avoided by all means.
Second, launch both compose instances with the same Docker network.
Third, do not expose ports - inside bridge network all ports are accessible to running containers.
Create global network
docker network create foo
Modify both compose files so that they use this network instead of creating each one its own:
version: '3.5'
services:
....
networks:
default:
external: true
name: foo
Remove expose directives from compose files - inside one network all ports are exposed by default
Modify connection strings to use default 3306 port instead of 3308
Enjoy

Answer 3

In order for the service to connect with MySql through docker it has to be in same network, look into Docker network
But for better solution I would suggest you to write a single docker compose file for MySql and Spring boot.The reason is it will easily be linked when you do that.No need any other configuration.
version: "3"
services:
mysql-service:
image: mysql
ports:
- "3306:3306"
environment:
- MYSQL_DATABASE=db
- MYSQL_USER=root
- MYSQL_PASSWORD=pass
- MYSQL_ROOT_PASSWORD=pass
spring-service:
image: springservce:latest
ports:
- "8080:8080"
depends_on:
- mysql-service

Answer 4

Before you try to connect to the Docker container you should stop mysql in your computer then go to the application.properties and type:
spring.datasource.url=jdbc:mysql://localhost:3306/NAME_OF_YOUR_DB_HERE?useSSL=false&allowPublicKeyRetrieval=true
Regarding localhost, you should inspect the mysql container and pick the IP address and use it instead. most likely is 172.17.0.2. If it did not work then use localhost.