Google Account (Gmail or Google Apps) and access to Google Cloud Platform console (console.cloud.google.com), see: https://cloud.google.com/free/ whether you're for a free tier $300 credit with an expiry of one year.
Activate the Cloud Shell to provision the Google Cloud Resources used by the application:
$ gcloud config set project <PROJECT_ID>
$ gcloud services enable pubsub.googleapis.com
$ gcloud services enable sqladmin.googleapis.com
$ gcloud pubsub topics create registrations
$ gcloud pubsub subscriptions create registrations-sub --topic=registrations
$ gcloud pubsub topics create posts
$ gcloud sql instances create codelab-instance --region=europe-west4
$ gcloud sql databases create registrants --instance codelab-instance
Note that when you create sql instances with gcloud sql instances create the default database engine is MySQL 5.7.
In the Cloud Shell, checkout the code:
$ git clone https://github.com/cristinanegrean/spring-cloud-gcp-pubsub-kotlin.git
$ cd spring-cloud-gcp-pubsub-kotlin/
Launch the code editor (pencil icon in Cloud Shell). In the Code Editor explore the project's files, locate and open src/main/resources/application.properties.
Edit spring.cloud.gcp.sql.instance-connection-name replace <PROJECT_ID>. At this point you can run the application from Cloud Shell terminal panel:
$ ./mvnw spring-boot:run
Open the Web Preview (eye icon in Cloud Shell) to visualise the application form used to interact with Google Cloud Pub/Sub.
- Publishing to topics and consuming messages from subscriptions asynch (both polling and streaming way) using Spring Cloud GCP Pub/Sub integration
- Storing data to managed MySQL database using Spring Cloud GCP SQL integration
- Kotlin with Spring Boot Data JPA and Spring Web MVC
For further info see (original codelab)[https://codelabs.developers.google.com/codelabs/cloud-spring-cloud-gcp-kotlin] which I have based my own playground on, with some modifications to try out consuming from Pub/Sub in a streaming way.