How to move Java REST application to Google Cloud - google-cloud-platform

Question

I have REST API Java application and want move it to cloud.
But I don't understand which tutorial use.
I already have docker image in Container Registry made by Jib and want connect it with some cloud database (Cloud SQL/Spanner).
How change this connection props to cloud?
db.driver=com.mysql.cj.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/db
db.username=usrname
db.password=pswd
db.entity.package = com.example.model

Answer 1

We do this through Cloud SQL Proxy docker image: https://cloud.google.com/sql/docs/mysql/connect-docker
Enable the Cloud SQL Admin API.
Install the mysql client on the Compute Engine instance or client machine, if it is not already installed.
If needed, install the Docker client
4.Install the Proxy Docker image from the Google Container Registry.
If you are running the Proxy Docker image on a local machine (not a Compute Engine instance), or your Compute Engine instance does not have the proper scopes, create a Google Cloud Platform service account.
Go to the Cloud SQL Instances page in the Google Cloud Console.
Select the instance to open its Instance details page and copy the Instance connection name.
Start the proxy.
docker run -d \
-v <PATH_TO_KEY_FILE>:/config \
-p 127.0.0.1:3306:3306 \
gcr.io/cloudsql-docker/gce-proxy:1.16 /cloud_sql_proxy \
-instances=<INSTANCE_CONNECTION_NAME>=tcp:0.0.0.0:3306 - credential_file=/config
Start the client
mysql -u <USERNAME> -p --host 127.0.0.1
Then connect using
db.driver=com.mysql.cj.jdbc.Driver
db.url=jdbc:mysql://127.0.0.1:3306/db
db.username=usrname
db.password=pswd
db.entity.package = com.example.model

Answer 2

If you want to reach a CloudSQL database from a GKE cluster, you have 2 solutions:
You can use configure a private ip on CloudSQL and then reach it directly to this IP. For this, your GKE cluster must be configured as VPC native.
You can attach a sidecar to your main container which open a cloud sql proxy connection to your database. This solution is quite similar of the answer of #ParthMehta. Here the description (and the github example) of this sidecar configuration
For Spanner, it's different because you can't use private IP or cloud SQL proxy binary. you have details on this page for the configuration and the dependencies
As you can see, you connect your instance directly with the ressource definition (/projects/..../instance/.......). Your config file should look like to this:
db.driver=com.google.cloud.spanner.jdbc.JdbcDriver
db.url=jdbc:cloudspanner:/projects/{YOUR_PROJECT_ID}/instances/{YOUR_INSTANCE_ID}/databases/{YOUR_DATABASE_ID}
db.dialect=com.google.cloud.spanner.hibernate.SpannerDialect