Ability to generate gRPC descriptor set

docs/src/main/asciidoc/grpc-generation-reference.adoc

@@ -99,7 +99,22 @@
 }
 ----
 
+== Generating Descriptor Set
+Protocol Buffers do not contain descriptions of their own types. Thus, given only a raw message without the corresponding .proto file defining its type, it is difficult to extract any useful data. However, the contents of a .proto file can itself be https://protobuf.dev/programming-guides/techniques/#self-description[represented using protocol buffers].
+
+By default, Quarkus does not generate these descriptors. Quarkus does provide several configuration options for generating them. These would be added to your `application.properties` or `application.yml` file:
+
+* `quarkus.generate-code.grpc.descriptor-set.generate`
+** Set to `true` to enable generation
+* `quarkus.generate-code.grpc.descriptor-set.output-dir`
+** Set this to a value relative to the project's build directory (i.e. `target` for Maven, `build` for Gradle)
+** Maven default value: `target/generated-sources/grpc`
+** Gradle default value: `$buildDir/classes/java/quarkus-generated-sources/grpc`
+* `quarkus.generate-code.grpc.descriptor-set.name`
+** Name of the descriptor set file to generate
+** Default value: `descriptor_set.dsc`
+
 == Configuring gRPC code generation for dependencies
 
 You may have dependencies that contain `\*.proto` files you want to compile to Java sources.
 This section explains how to configure code generation to include these `\*.proto` files during code generation.

extensions/grpc/codegen/src/main/java/io/quarkus/grpc/deployment/GrpcCodeGen.java

@@ -1,5 +1,6 @@
 package io.quarkus.grpc.deployment;
 
+import static java.lang.Boolean.FALSE;
 import static java.lang.Boolean.TRUE;
 import static java.util.Arrays.asList;
 
@@ -56,6 +57,9 @@ public class GrpcCodeGen implements CodeGenProvider {
     private static final String SCAN_FOR_IMPORTS = "quarkus.generate-code.grpc.scan-for-imports";
 
     private static final String POST_PROCESS_SKIP = "quarkus.generate.code.grpc-post-processing.skip";
+    private static final String GENERATE_DESCRIPTOR_SET = "quarkus.generate-code.grpc.descriptor-set.generate";
+    private static final String DESCRIPTOR_SET_OUTPUT_DIR = "quarkus.generate-code.grpc.descriptor-set.output-dir";
+    private static final String DESCRIPTOR_SET_FILENAME = "quarkus.generate-code.grpc.descriptor-set.name";
 
     private Executables executables;
     private String input;
@@ -149,6 +153,11 @@ public boolean trigger(CodeGenContext context) throws CodeGenException {
                         "--q-grpc_out=" + outDir,
                         "--grpc_out=" + outDir,
                         "--java_out=" + outDir));
+
+                if (shouldGenerateDescriptorSet(context.config())) {
+                    command.add(String.format("--descriptor_set_out=%s", getDescriptorSetOutputFile(context)));
+                }
+
                 command.addAll(protoFiles);
 
                 ProcessBuilder processBuilder = new ProcessBuilder(command);
@@ -262,6 +271,25 @@ private boolean isGeneratingFromAppDependenciesEnabled(Config config) {
                 .filter(value -> !"none".equals(value)).isPresent();
     }
 
+    private boolean shouldGenerateDescriptorSet(Config config) {
+        return config.getOptionalValue(GENERATE_DESCRIPTOR_SET, Boolean.class).orElse(FALSE);
+    }
+
+    private Path getDescriptorSetOutputFile(CodeGenContext context) throws IOException {
+        var dscOutputDir = context.config().getOptionalValue(DESCRIPTOR_SET_OUTPUT_DIR, String.class)
+                .map(context.workDir()::resolve)
+                .orElseGet(context::outDir);
+
+        if (Files.notExists(dscOutputDir)) {
+            Files.createDirectories(dscOutputDir);
+        }
+
+        var dscFilename = context.config().getOptionalValue(DESCRIPTOR_SET_FILENAME, String.class)
+                .orElse("descriptor_set.dsc");
+
+        return dscOutputDir.resolve(dscFilename).normalize();
+    }
+
     private Collection<String> gatherDirectoriesWithImports(Path workDir, CodeGenContext context) throws CodeGenException {
         Config properties = context.config();
 

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/build.gradle

@@ -0,0 +1,33 @@
+plugins {
+    id 'java'
+    id 'io.quarkus'
+}
+
+repositories {
+    mavenLocal {
+        content {
+            includeGroupByRegex 'io.quarkus.*'
+            includeGroup 'org.hibernate.orm'
+        }
+    }
+    mavenCentral()
+    gradlePluginPortal()
+}
+
+dependencies {
+    implementation enforcedPlatform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}")
+    implementation 'io.quarkus:quarkus-resteasy'
+    implementation 'io.quarkus:quarkus-grpc'
+}
+
+group 'org.acme'
+version '1.0.0-SNAPSHOT'
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
+
+test {
+    systemProperty "java.util.logging.manager", "org.jboss.logmanager.LogManager"
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/gradle.properties

@@ -0,0 +1,2 @@
+quarkusPlatformArtifactId=quarkus-bom
+quarkusPlatformGroupId=io.quarkus

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/settings.gradle

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        mavenLocal {
+            content {
+                includeGroupByRegex 'io.quarkus.*'
+                includeGroup 'org.hibernate.orm'
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+    plugins {
+        id 'io.quarkus' version "${quarkusPluginVersion}"
+    }
+}
+rootProject.name = 'grpc-descriptor-set-alternate-output-dir'

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/src/main/java/org/acme/quarkus/sample/HelloResource.java

@@ -0,0 +1,21 @@
+package org.acme.quarkus.sample;
+
+import jakarta.inject.Inject;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+
+import io.quarkus.example.HelloMsg;
+
+@Path("/hello")
+public class HelloResource {
+
+    @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    public String hello() {
+        Integer number = HelloMsg.Status.TEST_ONE.getNumber();
+        // return a thing from proto file (for devmode test)
+        return "hello " + number;
+    }
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/src/main/proto/hello.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+package io.quarkus.example;
+
+option java_multiple_files = true;
+option java_package = "io.quarkus.example";
+
+import "google/protobuf/timestamp.proto";
+
+
+message HelloMsg {
+  enum Status {
+    UNKNOWN = 0;
+    NOT_SERVING = 1;
+    TEST_ONE = 2;
+  }
+  string message = 1;
+  google.protobuf.Timestamp date_time = 2;
+  Status status = 3;
+}
+
+service DevModeService {
+  rpc Check(HelloMsg) returns (HelloMsg);
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output-dir/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+quarkus.generate-code.grpc.descriptor-set.generate=true
+quarkus.generate-code.grpc.descriptor-set.name=hello.dsc
+quarkus.generate-code.grpc.descriptor-set.output-dir=proto

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/build.gradle

@@ -0,0 +1,33 @@
+plugins {
+    id 'java'
+    id 'io.quarkus'
+}
+
+repositories {
+    mavenLocal {
+        content {
+            includeGroupByRegex 'io.quarkus.*'
+            includeGroup 'org.hibernate.orm'
+        }
+    }
+    mavenCentral()
+    gradlePluginPortal()
+}
+
+dependencies {
+    implementation enforcedPlatform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}")
+    implementation 'io.quarkus:quarkus-resteasy'
+    implementation 'io.quarkus:quarkus-grpc'
+}
+
+group 'org.acme'
+version '1.0.0-SNAPSHOT'
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
+
+test {
+    systemProperty "java.util.logging.manager", "org.jboss.logmanager.LogManager"
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/gradle.properties

@@ -0,0 +1,2 @@
+quarkusPlatformArtifactId=quarkus-bom
+quarkusPlatformGroupId=io.quarkus

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/settings.gradle

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        mavenLocal {
+            content {
+                includeGroupByRegex 'io.quarkus.*'
+                includeGroup 'org.hibernate.orm'
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+    plugins {
+        id 'io.quarkus' version "${quarkusPluginVersion}"
+    }
+}
+rootProject.name = 'grpc-descriptor-set-alternate-output'

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/src/main/java/org/acme/quarkus/sample/HelloResource.java

@@ -0,0 +1,21 @@
+package org.acme.quarkus.sample;
+
+import jakarta.inject.Inject;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+
+import io.quarkus.example.HelloMsg;
+
+@Path("/hello")
+public class HelloResource {
+
+    @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    public String hello() {
+        Integer number = HelloMsg.Status.TEST_ONE.getNumber();
+        // return a thing from proto file (for devmode test)
+        return "hello " + number;
+    }
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/src/main/proto/hello.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+package io.quarkus.example;
+
+option java_multiple_files = true;
+option java_package = "io.quarkus.example";
+
+import "google/protobuf/timestamp.proto";
+
+
+message HelloMsg {
+  enum Status {
+    UNKNOWN = 0;
+    NOT_SERVING = 1;
+    TEST_ONE = 2;
+  }
+  string message = 1;
+  google.protobuf.Timestamp date_time = 2;
+  Status status = 3;
+}
+
+service DevModeService {
+  rpc Check(HelloMsg) returns (HelloMsg);
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set-alternate-output/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+quarkus.generate-code.grpc.descriptor-set.generate=true
+quarkus.generate-code.grpc.descriptor-set.name=hello.dsc

integration-tests/gradle/src/main/resources/grpc-descriptor-set/build.gradle

@@ -0,0 +1,33 @@
+plugins {
+    id 'java'
+    id 'io.quarkus'
+}
+
+repositories {
+    mavenLocal {
+        content {
+            includeGroupByRegex 'io.quarkus.*'
+            includeGroup 'org.hibernate.orm'
+        }
+    }
+    mavenCentral()
+    gradlePluginPortal()
+}
+
+dependencies {
+    implementation enforcedPlatform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}")
+    implementation 'io.quarkus:quarkus-resteasy'
+    implementation 'io.quarkus:quarkus-grpc'
+}
+
+group 'org.acme'
+version '1.0.0-SNAPSHOT'
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
+
+test {
+    systemProperty "java.util.logging.manager", "org.jboss.logmanager.LogManager"
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set/gradle.properties

@@ -0,0 +1,2 @@
+quarkusPlatformArtifactId=quarkus-bom
+quarkusPlatformGroupId=io.quarkus

integration-tests/gradle/src/main/resources/grpc-descriptor-set/settings.gradle

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        mavenLocal {
+            content {
+                includeGroupByRegex 'io.quarkus.*'
+                includeGroup 'org.hibernate.orm'
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+    plugins {
+        id 'io.quarkus' version "${quarkusPluginVersion}"
+    }
+}
+rootProject.name = 'grpc-descriptor-set'

integration-tests/gradle/src/main/resources/grpc-descriptor-set/src/main/java/org/acme/quarkus/sample/HelloResource.java

@@ -0,0 +1,21 @@
+package org.acme.quarkus.sample;
+
+import jakarta.inject.Inject;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+
+import io.quarkus.example.HelloMsg;
+
+@Path("/hello")
+public class HelloResource {
+
+    @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    public String hello() {
+        Integer number = HelloMsg.Status.TEST_ONE.getNumber();
+        // return a thing from proto file (for devmode test)
+        return "hello " + number;
+    }
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set/src/main/proto/hello.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+package io.quarkus.example;
+
+option java_multiple_files = true;
+option java_package = "io.quarkus.example";
+
+import "google/protobuf/timestamp.proto";
+
+
+message HelloMsg {
+  enum Status {
+    UNKNOWN = 0;
+    NOT_SERVING = 1;
+    TEST_ONE = 2;
+  }
+  string message = 1;
+  google.protobuf.Timestamp date_time = 2;
+  Status status = 3;
+}
+
+service DevModeService {
+  rpc Check(HelloMsg) returns (HelloMsg);
+}

integration-tests/gradle/src/main/resources/grpc-descriptor-set/src/main/resources/application.properties

@@ -0,0 +1 @@
+quarkus.generate-code.grpc.descriptor-set.generate=true