Docker image with Spring boot fails to connect to CloudSQL - spring-boot

Question

I want to create web services with Spring boot, add it to docker image, connect to cloud sql and then run on Compute Engine.
I am using docker compose to combine the image for project and cloud sql proxy image. However, no matter what jdbc URL I give it fails to connect. Right now, I am trying all of this locally
I have tried following URLs:
1. spring.datasource.url=jdbc:mysql:///cloudsql/myinstancename/${MYSQL_DATABASE}
2. spring.datasource.url=jdbc:mysql://cloudsql/myinstancename/${MYSQL_DATABASE}
3. spring.datasource.url=jdbc:mysql://127.0.0.1:3306/${MYSQL_DATABASE}
docker-compose.yml
version: '3'
services:
app:
image: appname
volumes:
- cloudsql:/cloudsql
depends_on:
- sql_proxy
ports:
- 8080:8080
# SQL proxy is built correctly, says
# Listening on /cloudsql/myinstancename for myinstancename
# sql_proxy_1 | Ready for new connections
sql_proxy:
environment:
- MYSQL_ROOT_PASSWORD=password!#
- MYSQL_DATABASE=appname
- MYSQL_USER=root
image: gcr.io/cloudsql-docker/gce-proxy:1.12
command:
/cloud_sql_proxy
-dir=/cloudsql
-instances=myinstancename # (I have added this correctly)
-credential_file=/root/keys/keyfile.json
volumes:
- E:\mykey.json:/root/keys/keyfile.json:ro
- cloudsql:/cloudsql
ports:
- 3306:3306
volumes:
# This empty property initializes a named volume.
cloudsql:
application.properties:
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql:///cloudsql/myinstancename/${MYSQL_DATABASE}
spring.datasource.username=${MYSQL_USER}
spring.datasource.password=${MYSQL_ROOT_PASSWORD}
spring.security.enabled=false
security.ignored=/**

Answer 1

Currently, you are using the Cloud SQL proxy in a sidecar pattern that is mounting a unix socket in /cloudsql/<INSTANCE_CONNECTION_NAME> that can be used to connect to your Cloud SQL instance. Unfortunately, most Java JDBC drivers don't support unix sockets. You can switch the Cloud SQL Proxy to provide a tcp socket instead with something like the following: "-instances=<INSTANCE_CONNECTION_NAME>=tcp:3306".
Alternatively, you can use the Cloud SQL JDBC Socket Factory. This is a Java library that allows you to create authenticated connections to a Cloud SQL instance, but doesn't require using the proxy.