Add entry for spring-projects-experimental/spring-grpc

[mhalbritter]

Project: https://github.com/spring-projects-experimental/spring-grpc

Maven sample: https://github.com/spring-projects-experimental/spring-grpc/blob/main/samples/grpc-server/pom.xml

Gradle Groovy sample: https://github.com/spring-projects-experimental/spring-grpc/blob/main/samples/grpc-server/build.gradle

[mhalbritter]

For Gradle, we need to:

• Add id 'com.google.protobuf' version '0.9.4' plugin.
• Add https://repo.spring.io/milestone and/or https://repo.spring.io/snapshot repos
• Do a mavenBom 'org.springframework.grpc:spring-grpc-dependencies:0.2.0' dependency import
• Add implementation 'org.springframework.grpc:spring-grpc-spring-boot-starter'
• Add implementation 'io.grpc:grpc-services'
• Add testImplementation 'org.springframework.grpc:spring-grpc-test'
• Configure the protobuf plugin:

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:${dependencyManagement.importedProperties['protobuf-java.version']}"
    }
    plugins {
        grpc {
            artifact = "io.grpc:protoc-gen-grpc-java:${dependencyManagement.importedProperties['grpc.version']}"
        }
    }
    generateProtoTasks {
        all()*.plugins {
            grpc {
		option 'jakarta_omit'
	    }
	}
    }
}

However, using dependencyManagement.importedProperties triggers spring-gradle-plugins/dependency-management-plugin#193. Maybe we can workaround by using a provider.

[dsyer]

Only if actuator is selected, too?

That's not the determining factor. There are other services included (e.g. reflection service that is needed for grpcurl clients). So I would say make it unconditional (and user can opt out later).

[mhalbritter]

If spring-projects-experimental/spring-grpc#79 is implemented, the Gradle configuration is simplified:

protobuf {
    protoc {
        artifact = 'com.google.protobuf:protoc'
    }
    plugins {
        grpc {
            artifact = 'io.grpc:protoc-gen-grpc-java'
        }
    }
    generateProtoTasks {
        all()*.plugins {
            grpc {
                option 'jakarta_omit'
            }
        }
    }
}

[mhalbritter]

Here's the Kotlin DSL equivalent:

import com.google.protobuf.gradle.id

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc"
    }
    plugins {
        id("grpc") {
            artifact = "io.grpc:protoc-gen-grpc-java"
        }
    }
    generateProtoTasks {
        all().forEach { task ->
            task.plugins {
                id("grpc") {
                    option("jakarta_omit")
                }
            }
        }
    }
}

[mhalbritter]

For Maven, we would need:

Two properties which are used for the protobuf-maven-plugin configuration

<protobuf-java.version>3.25.5</protobuf-java.version>
<grpc.version>1.63.2</grpc.version>

• TODO: Is there a better way to handle this? It's very easy that those versions diverge from the versions of spring-grpc-dependencies.

Scope import spring-grpc-dependencies:

<dependency>
    <groupId>org.springframework.grpc</groupId>
    <artifactId>spring-grpc-dependencies</artifactId>
    <version>0.3.0-SNAPSHOT</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

Add those dependencies:

<dependency>
    <groupId>org.springframework.grpc</groupId>
    <artifactId>spring-grpc-spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-services</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.grpc</groupId>
    <artifactId>spring-grpc-test</artifactId>
    <scope>test</scope>
</dependency>

Add a build extension to get the architecture later needed to download protoc:

<build>
    <extensions>
        <extension>
            <groupId>kr.motd.maven</groupId>
            <artifactId>os-maven-plugin</artifactId>
            <version>1.7.1</version>
        </extension>
    </extensions>
// ...

Add protobuf-maven-plugin:

<plugin>
    <groupId>org.xolstice.maven.plugins</groupId>
    <artifactId>protobuf-maven-plugin</artifactId>
    <version>0.6.1</version>
    <configuration>
        <protocArtifact>com.google.protobuf:protoc:${protobuf-java.version}:exe:${os.detected.classifier}</protocArtifact>
        <pluginId>grpc-java</pluginId>
        <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
    </configuration>
    <executions>
        <execution>
            <configuration>
                <pluginParameter>
                    jakarta_omit
                </pluginParameter>
            </configuration>
            <goals>
                <goal>compile</goal>
                <goal>compile-custom</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Add spring-milestones and/or spring-snapshots repositories.

That would mean that start.spring.io needs to know the versions of those dependencies:

• 3.25.5 for protobuf-java.version (maybe we can read that from spring-grpc-dependencies)
• 1.63.2 for grpc.version (maybe we can read that from spring-grpc-dependencies)
• 1.7.1 for os-maven-plugin
• 0.6.1 for protobuf-maven-plugin