Implement GeneratePackage

The `GeneratePackage` method of the `LanguageRuntime` gRPC service allows
callers to generate SDKs for a specified schema. This commits implements this
endpoint for `pulumi-language-java`, using the existing `pkg/codegen`
functionality that is currently only exposed through the `pulumi-java-gen`
binary. Doing so means we can begin to get conformance tests working for Java.

As part of this work, we extend the work we started when implementing
`GenerateProject` to support local repositories in generated SDKs. As with other
languages, we add a field to `PackageInfo` to this end. Since SDK generation
uses Gradle (and not Maven, as program generation does), there is a bit of new
plumbing to do here, but in principle the outcome is the same.

> [!NOTE]
> It is not certain yet that `GeneratePackage` behaves identically to the
> currently-used binary endpoint in `pulumi-java-gen` -- we should make sure of
> this before switching over. This work is primarily a means to get conformance
> tests going.

CHANGELOG_PENDING.md

@@ -4,4 +4,6 @@
 
 - Implement `GenerateProgram` and `GenerateProject` RPC endpoints for Java
 
+- Implement the `GeneratePackage` RPC endpoint for Java
+
 ### Bug Fixes

pkg/cmd/pulumi-language-java/main.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -29,6 +30,7 @@ import (
 	"github.com/pulumi/pulumi/sdk/v3/go/common/version"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/workspace"
 	pulumirpc "github.com/pulumi/pulumi/sdk/v3/proto/go"
+	"golang.org/x/exp/maps"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/protobuf/types/known/structpb"
@@ -675,3 +677,93 @@ func (host *javaLanguageHost) GenerateProgram(
 		Diagnostics: rpcDiagnostics,
 	}, nil
 }
+
+// Implements the `LanguageRuntime.GeneratePackage` RPC method, which generates a Java SDK package from a supplied
+// schema.
+func (host *javaLanguageHost) GeneratePackage(
+	_ context.Context,
+	req *pulumirpc.GeneratePackageRequest,
+) (*pulumirpc.GeneratePackageResponse, error) {
+	loader, err := schema.NewLoaderClient(req.LoaderTarget)
+	if err != nil {
+		return nil, err
+	}
+
+	var spec schema.PackageSpec
+	err = json.Unmarshal([]byte(req.Schema), &spec)
+	if err != nil {
+		return nil, err
+	}
+
+	pkg, diags, err := schema.BindSpec(spec, loader)
+	if err != nil {
+		return nil, err
+	}
+	rpcDiagnostics := plugin.HclDiagnosticsToRPCDiagnostics(diags)
+	if diags.HasErrors() {
+		return &pulumirpc.GeneratePackageResponse{
+			Diagnostics: rpcDiagnostics,
+		}, nil
+	}
+
+	if pkg.Description == "" {
+		pkg.Description = " "
+	}
+	if pkg.Repository == "" {
+		pkg.Repository = "https://example.com"
+	}
+
+	// Presently, we only support generating Java SDKs which use Gradle as a build system. Specify that here, as well as
+	// the set of dependencies that all generated SDKs rely on.
+	pkgInfo := codegen.PackageInfo{
+		BuildFiles: "gradle",
+		Dependencies: map[string]string{
+			"com.google.code.gson:gson":       "2.8.9",
+			"com.google.code.findbugs:jsr305": "3.0.2",
+		},
+	}
+
+	repositories := map[string]bool{}
+
+	for name, dep := range req.LocalDependencies {
+		parts := strings.Split(dep, ":")
+		if len(parts) < 3 {
+			return nil, fmt.Errorf(
+				"invalid dependency for %s %s; must be of the form groupId:artifactId:version[:repositoryPath]",
+				name, dep,
+			)
+		}
+
+		k := parts[0] + ":" + parts[1]
+		pkgInfo.Dependencies[k] = parts[2]
+
+		if len(parts) == 4 {
+			repositories[parts[3]] = true
+		}
+	}
+
+	pkgInfo.Repositories = maps.Keys(repositories)
+	pkg.Language["java"] = pkgInfo
+
+	files, err := codegen.GeneratePackage("pulumi-language-java", pkg, req.ExtraFiles, req.Local)
+	if err != nil {
+		return nil, err
+	}
+
+	for filename, data := range files {
+		outPath := filepath.Join(req.Directory, filename)
+		err := os.MkdirAll(filepath.Dir(outPath), 0o700)
+		if err != nil {
+			return nil, fmt.Errorf("could not create output directory %s: %w", filepath.Dir(filename), err)
+		}
+
+		err = os.WriteFile(outPath, data, 0o600)
+		if err != nil {
+			return nil, fmt.Errorf("could not write output file %s: %w", filename, err)
+		}
+	}
+
+	return &pulumirpc.GeneratePackageResponse{
+		Diagnostics: rpcDiagnostics,
+	}, nil
+}

pkg/codegen/java/build.gradle.template

@@ -43,6 +43,11 @@ compileJava {
 }
 
 repositories {
+    {{- range $url := .Repositories }}
+    maven {
+        url("{{ $url }}")
+    }
+    {{- end }}
     mavenLocal()
     maven { // The google mirror is less flaky than mavenCentral()
         url("https://maven-central.storage-download.googleapis.com/maven2/")

pkg/codegen/java/package_info.go

@@ -76,6 +76,11 @@ type PackageInfo struct {
 	// Gradle build files.
 	BuildFiles string `json:"buildFiles"`
 
+	// If non-empty, specifies a list of Maven repositories that should be
+	// referenced by the generated package. This can be useful for specifying
+	// the locations of e.g. local or private dependencies.
+	Repositories []string `json:"repositories,omitempty"`
+
 	// Specifies Maven-style dependencies for the generated code.
 	//
 	// The dependency on Java SDK (com.pulumi:pulumi) is special

pkg/codegen/java/templates_gradle.go

@@ -7,6 +7,7 @@ import (
 	_ "embed"
 	"fmt"
 	"net/url"
+	"slices"
 	"strings"
 
 	"github.com/pulumi/pulumi/pkg/v3/codegen/schema"
@@ -74,6 +75,7 @@ type gradleTemplateContext struct {
 	ProjectGitURL                   string
 	ProjectDescription              string
 	ProjectInceptionYear            string
+	Repositories                    []string
 	Dependencies                    map[string]string
 	DeveloperID                     string
 	DeveloperName                   string
@@ -110,6 +112,13 @@ func newGradleTemplateContext(
 		ctx.Version = "0.0.1"
 	}
 
+	if packageInfo.Repositories != nil {
+		ctx.Repositories = packageInfo.Repositories
+		slices.Sort(ctx.Repositories)
+	} else {
+		ctx.Repositories = []string{}
+	}
+
 	if packageInfo.Dependencies != nil {
 		ctx.Dependencies = packageInfo.Dependencies
 	} else {