访问spring启动应用程序.properties中提到的配置文件，在创建.jar后用于App引擎部署

Question

I am facing big trouble in deploying a spring boot application in GCP AppEngine with cloud Postgres as a database. Earlier I was using tcp connection jdbc with IP whitelisting to access the database, which worked fine during testing but after deploying into Appengine it didn't warmed up due to sslsocket timed out . So after a bit of digging, I found for standard appengine runtime to connect a cloud Postgres I have to use postgres socket factory

        <dependency>
            <groupId>com.google.cloud.sql</groupId>
            <artifactId>postgres-socket-factory</artifactId>
            <version>1.2.2</version>
        </dependency>

with spring.datasource.url=jdbc:postgresql:///{REDACT}?cloudSqlInstance={REDACT}&socketFactory=com.google.cloud.sql.postgres.SocketFactory&user={REDACT}&password={REDACT} in application.properties.

But GCP needs to verify the connection from the key generated from the service account with specific privileges which has been added to the application.properties. spring.cloud.gcp.credentials.location=classpath:gcloud.json

But in java the built jar file can't access the json, nor the deployed appengine instance. Here's the error

[Screenshot error in App engine][1]

app.yaml

runtime: java11

pom.xml

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-gcp-starter-sql-postgresql</artifactId>
            <version>1.2.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.19</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.google.cloud.sql</groupId>
            <artifactId>postgres-socket-factory</artifactId>
            <version>1.2.2</version>
        </dependency>

Any reply would be of great help. Thanks [1]: https://i.stack.imgur.com/gEV2r.png

Answer 1

With App Engine you don't need to use a service account key file. You can rely on the metadata server that provides automatically App Engine service account credential. Service account is not customizable for now, but should change in 2021: It name is the following: <projectID>@appspot.gserviceaccount.com

Be sure that this service account has enough Cloud SQL permissions (by default, it has Editor role on the project, and have enough (and even too much!!) permissions)

So, use the Cloud SQL App Engine connector in the app.yaml file to set up the connection with Cloud SQL and open a socket (to connect with socket factory) in your code