Connect App Engine to Google cloud SQL fails - kotlin

Question

I'm following this guide
I'm filling the config like this:
val datasourceConfig = HikariConfig().apply {
jdbcUrl = "jdbc:mysql:///$DB_NAME"
username = DB_PASS
password = DB_USER
mapOf(
"cloudSqlInstance" to CLOUD_SQL_CONNECTION_NAME,
"socketFactory" to "com.google.cloud.sql.mysql.SocketFactory",
"ipTypes" to "PUBLIC,PRIVATE",
).forEach {
addDataSourceProperty(
it.key,
it.value
)
}
}
output of the gcloud sql instances describe project-name:
backendType: SECOND_GEN
connectionName: project-name:europe-west1:project-name-db
databaseVersion: MYSQL_5_7
failoverReplica:
available: true
gceZone: europe-west1-d
instanceType: CLOUD_SQL_INSTANCE
ipAddresses:
- ipAddress: *.*.*.*
type: PRIMARY
kind: sql#instance
name: project-name-db
project: project-name
region: europe-west1
from which I'm filling my env variables:
DB_NAME=project-name-db
CLOUD_SQL_CONNECTION_NAME=project-name:europe-west1:project-name-db
On the deployed app line val dataSource = HikariDataSource(datasourceConfig) crashes with the following exception:
com.zaxxer.hikari.pool.HikariPool$PoolInitializationException: Failed to initialize pool: Cannot connect to MySQL server on localhost:3,306.
Make sure that there is a MySQL server running on the machine/port you are trying to connect to and that the machine this software is running on is able to connect to this host/port (i.e. not firewalled). Also make sure that the server has not been started with the --skip-networking flag.
update: I've tried adding google between second and third slashes("jdbc:mysql://google/$DB_NAME"), according to this answer, now I get:
Cannot connect to MySQL server on google:3,306.

Answer 1

I was missing the following dependency:
implementation("com.google.cloud.sql:mysql-socket-factory-connector-j-8:1.2.2")
more info here
Also DB_NAME is not name of gcloud sql instances output, but a database name that should be created in Console -> Project -> Sql -> Databases