tunnel: add gRPC over unix domain socket to the go backend

With gRPC it will be easier to extend the go backend API.
In this commit the Version function is reimplemented in gRPC.

Gitignore generated protobuf files.

1 files changed, 58 insertions, 0 deletions

diff --git a/tunnel/build.gradle.kts b/tunnel/build.gradle.kts
index fff3857d..7f6bd0e6 100644
--- a/tunnel/build.gradle.kts
+++ b/tunnel/build.gradle.kts
@@ -1,5 +1,6 @@
 @file:Suppress("UnstableApiUsage")
 
+import com.google.protobuf.gradle.*
 import org.gradle.api.tasks.testing.logging.TestLogEvent
 
 val pkg: String = providers.gradleProperty("wireguardPackageName").get()
@@ -7,6 +8,7 @@ val pkg: String = providers.gradleProperty("wireguardPackageName").get()
 plugins {
     alias(libs.plugins.android.library)
     `maven-publish`
+    alias(libs.plugins.google.protobuf)
     signing
 }
 
@@ -67,10 +69,66 @@ android {
 dependencies {
     implementation(libs.androidx.annotation)
     implementation(libs.androidx.collection)
+    implementation(libs.grpc.android)
+    implementation(libs.grpc.okhttp)
+    implementation(libs.grpc.protobuf.lite)
+    implementation(libs.grpc.stub)
+    compileOnly(libs.javax.annotation.api)
     compileOnly(libs.jsr305)
     testImplementation(libs.junit)
 }
 
+protobuf {
+    protoc {
+        // The artifact spec for the Protobuf Compiler
+        artifact = "com.google.protobuf:protoc:${libs.versions.protoc.get()}"
+    }
+    plugins {
+        // Optional: an artifact spec for a protoc plugin, with "grpc" as
+        // the identifier, which can be referred to in the "plugins"
+        // container of the "generateProtoTasks" closure.
+        id("grpc") {
+            artifact = "io.grpc:protoc-gen-grpc-java:${libs.versions.protocgengrpc.get()}"
+        }
+        id("java") {
+        }
+    }
+    generateProtoTasks {
+        all().forEach { task ->
+            task.plugins{
+                id("grpc") {
+                    option("lite")
+                }
+                id("java") {
+                    option("lite")
+                }
+            }
+        }
+    }
+}
+
+afterEvaluate({ ->
+    // All custom configurations created by the protobuf plugin,
+    // are only available at this point.
+    var protoc = configurations.named("protobufToolsLocator_protoc")
+    var protocCache = "${gradle.gradleUserHomeDir}/caches/protoc-bin-${libs.versions.protoc.get()}"
+
+    tasks.register("copyProtoc", Copy::class) {
+        // Used by tunnel/tools/libwg-go/Makefile run in tools/CMakeLists.txt
+        from(protoc)
+        into(protocCache)
+        rename("protoc-.*", "protoc")
+        setFileMode(7 * 64 + 7 * 8 + 5) // 0775
+    }
+
+    tasks.named("preBuild").get().dependsOn("copyProtoc")
+
+    // Extract duration.proto used by external library in libwg.proto
+    tasks.named("preDebugBuild").get().dependsOn(tasks.named("extractIncludeDebugProto").get())
+    tasks.named("preReleaseBuild").get().dependsOn(tasks.named("extractIncludeReleaseProto").get())
+    println("done afterEvaluate")
+})
+
 publishing {
     publications {
         register<MavenPublication>("release") {