pekko-persistence-app

pekko-persistence-app example project

pekko-persistence-app is an example project to show real usage of the Dump Persistence Schema Compiler Plugin. This project uses logic from the pekko-microservices-tutorial (the shopping-cart-service), with Pekko Serialization Helper added.

Dump Persistence Schema Compiler Plugin usage

You can test Dump Persistence Schema Compiler Plugin on this example project. There are two possibilities to do it:

• sbt compile - compiles the project with the dump-persistence-schema phase enabled. dump-persistence-schema phase dumps detected persistence schema (types for Events and States) into .json files under the target/dump-psersistence-schema-cache directory of this project. These .json files are cache files used later by the ashDumpPersistenceSchema sbt task.
• sbt ashDumpPersistenceSchema — sbt task that creates final output of the dump using mentioned .json files. Output is saved into the target/pekko-persistence-app-dump-persistence-schema-0.1.0-SNAPSHOT.yaml file. You can just invoke sbt ashDumpPersistenceSchema without sbt compile — ashDumpPersistenceSchema task will invoke sbt compile if needed.

Running the sample code

1. Prepare docker containers with:

   docker-compose up -d
   

2. Create database tables with:

   docker exec -i pekko-persistence-app_postgres-db_1 psql -U shopping-cart -t < ddl-scripts/create_tables.sql`
   

3. Start a first node:

   sbt "run local1.conf"
   

4. (Optional) Start another node with different ports:

   sbt "run local2.conf"
   

5. (Optional) Check for service readiness:

   curl http://localhost:9101/ready
   

6. Interact with the service using grpcurl - example request (put items in the cart):

   grpcurl -d '{"cartId":"cart1", "itemId":"T-shirt", "quantity":3}' -plaintext 127.0.0.1:8101 shoppingcart.ShoppingCartService.AddItem
   

7. Dump persistence schema with Pekko Serialization Helper (after shutting down the application):

   sbt ashDumpPersistenceSchema
   

Output saved into the target/pekko-persistence-app-dump-persistence-schema-0.1.0-SNAPSHOT.yaml file.