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

mysql spring spring-boot docker docker-compose

16,330

Solution 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.

Solution 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

Solution 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

16,330

Tomas Bisciak

Java programmer ,CS bachelors degree from the University of Ss. Cyril and Methodius in Trnava. Constantly trying to improve my skills :) I welcome edits to my answers/questions.

Updated on September 27, 2022

Comments

Tomas Bisciak over 1 year
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;"
```
- Tomas Bisciak almost 5 years
  
  @M.Deinum Still getting error Connection refused even when they are on same network
Tomas Bisciak almost 5 years

I will try it out
Tomas Bisciak almost 5 years

Will try it out
Tomas Bisciak almost 5 years

Bud if i remove use of 3308 I will clash with 3306 that i have running locally already (mysql database) that i test with from intellij ? Right?
Tomas Bisciak almost 5 years

services.workaround-mysql.networks.default contains unsupported option: 'external' and services.workaround-mysql.networks.default contains unsupported option: 'name'
grapes almost 5 years

Put version: '3.5' or later at the top of yaml files
grapes almost 5 years

"Bud if i remove use of 3308 I will clash with 3306 that i have running locally already (mysql database) that i test with from intellij ? Right?" No, you wont. 3306 will exist only inside network foo and will NOT be available outside. As far as I understood, you connect to db from another container, not from host. If I am wrong and you also need to connect from host, you will need to expose ports
Tomas Bisciak almost 5 years

Ok so after I have used code you send me , I have Caused by: java.net.ConnectException: Connection refused (Connection refused) I already had that before when i tried this approach. No success, Will update question with full output
Tomas Bisciak almost 5 years

Updated question with output to your answer.
Tomas Bisciak almost 5 years

Tried version 3.5 and 3.7 still getting unsupported option on external keyword (when i do docker-compose build)
grapes almost 5 years

docker-compose --version?
Tomas Bisciak almost 5 years

docker-compose version 1.23.2, build 1110ad01
Avi almost 5 years

The jdbc url in application.properties should be something like this "url=jdbc:mysql://mysql-service:3306/db" (In docke-compse.yml, I have mentioned my service name as 'mysql-service' and DB name as 'db' that's why have used the same value in the URL ).Same goes for username and password
Tomas Bisciak almost 5 years

I will test since i still used that 3308 , I will change it to 3306 and see if it changes from connection refused
Avi almost 5 years

@TomasBisciak, for you reference github.com/aviu95/user_mgt look into the code
Tomas Bisciak almost 5 years

Yes i made it work! Your answer was pretty close to what accepted answer is . Pretty much same, so thank you so much also!!
grapes almost 5 years

I've double checked this syntax, can you verify you have no misspellings and correct tabulation? Note - networks directive is GLOBAL, not related to any particular service
Tomas Bisciak almost 5 years

My fault didnt have it global ;) I have put it under service so that might be the case .Either way problem is solved by info in your answer will probably be used to further refine what i have now :D awesome