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License: Other

Scala 35.97% Java 63.78% Shell 0.26%

lagom java scala

lagom-recipes's Introduction

Deprecated - Lagom - July 1 2023

This project will only recieve security patches until July 1, 2024, at that point the project will no longer receive any additional patches.

If you are an existing customer of Lightbend and we have not yet contacted you, please reach out to Support.

We recommend migrating any existing work to:

Akka for deeply customized projects with complex infrastructure needs. Akka now contains the vast majority of Lagom features.
Kalix for a managed scalable environment with an abstraction above the Akka framework layer to allow you to focus only on business logic.

Lagom - The Reactive Microservices Framework

Lagom is a Swedish word meaning just right, sufficient. Microservices are about creating services that are just the right size, that is, they have just the right level of functionality and isolation to be able to adequately implement a scalable and resilient system.

Lagom focuses on ensuring that your application realizes the full potential of the Reactive Manifesto while delivering a high productivity development environment, and seamless production deployment experience.

Learn More

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this project except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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lagom-recipes's Issues

File Upload example using maven

Is there any example for file upload implementation using maven?

Make the contents of README searchable

copy/pasting the contents of the main README in the Lagom docs would make this recipies more easily searchable.

Lagom Recipes repository archival

We, the team of maintainers, have decided to make a few changes around the code structure, repository reorganization and maintained samples. One such change is the archiving of Lagom Recipes.

We decided to pick a few recipes into the new https://github.com/lagom/lagom-samples repository and archive https://github.com/lagom/lagom-recipes. That means that any recipe that was not moved to https://github.com/lagom/lagom-samples will not be editable anymore. We invite all recipe contributors to take their recipes under their umbrella and keep working on them. We'll be happy to cross-link to external repositories demonstrating how to build great features in Lagom, we just decided to not be a blocker to get this published. We will keep the index of external recipes on the https://github.com/lagom/lagom-samples repo and archive lagom-recipes preventing new changes.

Thanks all for your hard work, contributions, ideas and for pushing forward this collection of samples.

Implement a java equivalent of the file upload recipe

Recipe should be the java equivalent of https://github.com/lagom/lagom-recipes/tree/master/file-upload/file-upload-scala-sbt

This has come up a few times (e.g. https://discuss.lightbend.com/t/how-lagom-java-use-play-java-controller/909/3).

[couchbase] greetings repository always returns empty list

In both couchbase recipes the /api/user-greetings endpoint always returns [].

/cc @johanandren

Add a top-level README with repo purpose and TOC of recipes

K8s example suggestions

Taking the k8s example for a spin, some suggestions from our k8s engineer

All the env-variables except downwardAPI, might be better using a ConfigMap and then mount them as volumes. Only reason to use configMaps over Environment variables is you can change the ConfigMap on the fly and don’t need to re-create the whole deployment.
imagePullPolicy: IfNotPresent should be Always in case of Production because in case you have old image with same tag locally, it will never pull new images

my additional remark would be to remove the dependency on minikube and it's ingress and make something more generic, example based on istio which can be deployed on any k8s host (including docker for mac + k8s extension)

Review README to list all projects

e.g. at least log correlation is missing:

How do I use MDC-Log correlation IDs with Lightbend Telemetry (Cinnamon) in Lagom? ([Java/Maven example](./lightbend-telemetry/log-correlation-java-mvn/README.md))

Publish main README on LB's techhub

Adding the recipes on lightbend's techhub will increase visibility

Enable travis support

As lagom moves forward some recipes need upgrades as versions bump. It'd be great to have some form of build server to ease maintenance.

Import sample as recipe to demo Multi-rdbms

The sample https://github.com/ignasi35/lagom-scala-sbt-multiple-rdbms should be a recipe. Needs reviewing and more detailed explanation on the README.

It could be merged with https://github.com/ignasi35/lagom-multiple-databases to further demo other use cases.

Unable to modify mixed-persistence-java-sbt to use Postgres

These are the changes I tried to make to use Postgres: marvinmarnold@81b6f39

When I do sbt runAll, things start off nice:

16:17:04.840 [info] application [] - Creating Pool for datasource 'default'
16:17:04.851 [info] com.zaxxer.hikari.HikariDataSource [] - HikariPool-1 - Starting...
16:17:04.960 [info] com.zaxxer.hikari.HikariDataSource [] - HikariPool-1 - Start completed.
16:17:04.970 [info] play.api.db.HikariCPConnectionPool [] - datasource [default] bound to JNDI as DefaultDS
16:17:04.983 [info] play.api.db.DefaultDBApi [] - Database [default] connected at jdbc:postgresql://localhost:5431/postgres
16:17:05.659 [info] org.hibernate.jpa.internal.util.LogHelper [] - HHH000204: Processing PersistenceUnitInfo [
	name: default
	...]

But then the Postgres connection ultimately fails

16:17:06.795 [warn] org.hibernate.engine.jdbc.spi.SqlExceptionHelper [] - SQL Error: 0, SQLState: null
16:17:06.795 [error] org.hibernate.engine.jdbc.spi.SqlExceptionHelper [] - null
16:17:06.799 [warn] com.lightbend.lagom.internal.javadsl.persistence.jpa.JpaSessionImpl [] - Exception while initializing JPA EntityManagerFactory
javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:967)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892)
	at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:58)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
	at com.lightbend.lagom.internal.javadsl.persistence.jpa.JpaSessionImpl.lambda$createEntityManagerFactory$1(JpaSessionImpl.java:86)
	at com.lightbend.lagom.internal.javadsl.persistence.jpa.Retry.$anonfun$retry$1(Retry.scala:35)
	at scala.concurrent.Future$.$anonfun$apply$1(Future.scala:655)
	at scala.util.Success.$anonfun$map$1(Try.scala:251)
	at scala.util.Success.map(Try.scala:209)
	at scala.concurrent.Future.$anonfun$map$1(Future.scala:289)
	at scala.concurrent.impl.Promise.liftedTree1$1(Promise.scala:29)
	at scala.concurrent.impl.Promise.$anonfun$transform$1(Promise.scala:29)
	at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:60)
	at slick.util.AsyncExecutor$$anon$2$$anon$3$$anon$4.run(AsyncExecutor.scala:165)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.exception.GenericJDBCException: Unable to open JDBC Connection for DDL execution
	at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)
	at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
	at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
	at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:69)
	at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcConnection(ImprovedExtractionContextImpl.java:60)
	at org.hibernate.tool.schema.extract.internal.SequenceInformationExtractorLegacyImpl.extractMetadata(SequenceInformationExtractorLegacyImpl.java:40)
	at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.initializeSequences(DatabaseInformationImpl.java:65)
	at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.<init>(DatabaseInformationImpl.java:59)
	at org.hibernate.tool.schema.internal.Helper.buildDatabaseInformation(Helper.java:132)
	at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:96)
	at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183)
	at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
	at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:313)
	at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:452)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:889)
	... 16 common frames omitted
Caused by: java.sql.SQLFeatureNotSupportedException: null
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:135)
	at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
	at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:43)
	... 27 common frames omitted
16:17:06.800 [info] com.lightbend.lagom.internal.javadsl.persistence.jpa.JpaSessionImpl [] - Will retry initializing JPA EntityManagerFactory 10 times in 5 seconds

I'm able to connect to that DB from DBeaver using the same credentials. Port 5431 is intentional.

Update configuration for Cluster Bootstrap Discovery Method

This is the current configuration for the Cluster Bootstrap Discovery Method:

lagom-recipes/kubernetes-deployment/hello-kubernetes-java-mvn/hello-impl/src/main/resources/prod-application.conf

Lines 10 to 16 in 2203a64

    
           discovery { 
        
             method = kubernetes-api 
        
             kubernetes-api { 
        
               pod-label-selector = "appName=%s" 
        
               pod-namespace = ${?RP_NAMESPACE} 
        
             } 
        
           }

lagom-recipes/kubernetes-deployment/hello-kubernetes-java-mvn/stream-impl/src/main/resources/prod-application.conf

Lines 10 to 16 in 2203a64

    
           discovery { 
        
             method = kubernetes-api 
        
             kubernetes-api { 
        
               pod-label-selector = "appName=%s" 
        
               pod-namespace = ${?RP_NAMESPACE} 
        
             } 
        
           }

This globally sets the default discovery method to kubernetes-api, which is only appropriate to use for Cluster Bootstrap and not for inter-service discovery.

While this recipe does not currently use Akka Discovery for anything else, users are likely to copy it as it is. Anyone using the Akka gRPC integration will need another global default discovery method, and in the future, Lagom will have a ServiceLocator implementation based on Akka Discovery.

The recipe should be updated to set akka.management.cluster.bootstrap.contact-point-discovery.discovery-method instead of akka.discovery.method, as described in akka/akka-management#316.

JPA CRUD recipe

Add an example of using Play's JPA API to do CRUD-oriented persistence in a Lagom service.

Review licensing

Current LICENSE is Apache-2 abbreviated. We should:

use full Apache 2 text in LICENSE, or
use CC0/public domain, or
???

	discovery {
	method = kubernetes-api
	kubernetes-api {
	pod-label-selector = "appName=%s"
	pod-namespace = ${?RP_NAMESPACE}
	}
	}