I have an java spring / hibernate application and I cant create a connection beween the mysql and java containers. When I start just the mysql Container and run the java application manualy in CMD it works fine. But once the java application runs in a container I get the following problem:
bookAPI | com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
bookAPI |
bookAPI | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
bookAPI | at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.21.jar!/:8.0.21]
bookAPI | at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.21.jar!/:8.0.21]
If I understand the error correctly the java container can send to the mysql container but not the other way around. I have linked the java container to the mysql container. Anyone knows how to connect these containers correctly?
My docker-compose.yml looks like this:
version: '3'
services:
db:
image: mysql:5.7
container_name: mysql
environment:
MYSQL_ROOT_PASSWORD: aaaaaa
MYSQL_DATABASE: bookAPI
MYSQL_USER: aaaaaa
MYSQL_PASSWORD: aaaaaa
ports:
- 3306:3306
phpmyadmin:
image: phpmyadmin/phpmyadmin
container_name: phpmyadmin
links:
- db
environment:
PMA_HOST: db
PMA_PORT: 3306
PMA_ARBITRARY: 1
restart: always
ports:
- 8081:80
java:
container_name: bookAPI
image: openjdk:8
depends_on:
- db
volumes:
- ./:/app
working_dir: /app
command: bash -c "cd /app && java -jar bookAPI.jar"
stdin_open: true
tty: true
ports:
- 8080:8080
links:
- db
2
Answers
Okay, I solved the problem. To connect the spring application with another docker container you need to change the application.properties url value from localhost or ip to the docker maysql container name. Thats tricky while running it localy or run maven install so the best pracice is to overwrite it while starting the application in container.
You can also directly override the applications.properties with docker-compose environment variables like this :
I would recomment you tu use depends_on db instead of links