chore: add .NET gRPC wrapper

Adds a gRPC wrapper for .NET. This wrapper uses the gRPC API to connect to SpannerLib.
The gRPC channel uses a Unix domain socket.

Author: olavloite

.github/workflows/spanner-lib-tests.yml

@@ -97,6 +97,8 @@ jobs:
           go-version: ${{ matrix.go-version }}
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          submodules: 'true'
       - name: Build shared library
         working-directory: spannerlib/shared
         run: go build -o spannerlib.so -buildmode=c-shared shared_lib.go
@@ -124,10 +126,42 @@ jobs:
           fi
         working-directory: spannerlib/wrappers/spannerlib-dotnet/spannerlib-dotnet-native
         shell: bash
+      - name: Build gRPC server
+        working-directory: spannerlib/grpc-server
+        run: |
+          go build -o grpc_server server.go
+          chmod +x grpc_server
+      - name: Copy gRPC server to .NET wrapper
+        working-directory: spannerlib
+        run: |
+          mkdir -p wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-server/binaries/any
+          if [ "$RUNNER_OS" == "Windows" ]; then
+            cp grpc-server/grpc_server wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-server/binaries/any/grpc_server.exe
+          else
+            cp grpc-server/grpc_server wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-server/binaries/any/grpc_server
+          fi
+        shell: bash
+      - name: Build .NET gRPC server package
+        run: dotnet pack
+        working-directory: spannerlib/wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-server
+        shell: bash
+      - name: Add .NET package source
+        run: |
+          if [ "$RUNNER_OS" == "Windows" ]; then
+            dotnet nuget add source ${GITHUB_WORKSPACE}"\spannerlib\wrappers\spannerlib-dotnet\spannerlib-dotnet-grpc-server\bin\Release" --name local-grpc-server
+          else
+            dotnet nuget add source "$PWD"/bin/Release --name local-grpc-server
+          fi
+        working-directory: spannerlib/wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-server
+        shell: bash
       - name: Restore dependencies
         run: dotnet restore
         working-directory: spannerlib/wrappers/spannerlib-dotnet
         shell: bash
+      - name: Create proto symlinks
+        run: ./create-symlinks.sh
+        working-directory: spannerlib/wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc-impl
+        shell: bash
       - name: Build
         run: dotnet build --no-restore
         working-directory: spannerlib/wrappers/spannerlib-dotnet

spannerlib/grpc-server/build-dotnet-darwin-aarch64.sh

@@ -0,0 +1,4 @@
+go build -o grpc_server server.go
+chmod +x grpc_server
+cp grpc_server ../wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc/binaries/any/grpc_server
+cp grpc_server ../wrappers/spannerlib-dotnet/spannerlib-dotnet-grpc/binaries/osx-arm64/grpc_server

spannerlib/grpc-server/build-protos.sh

@@ -1,6 +1,5 @@
 PATH="${PATH}:${HOME}/go/bin"
-rm -rf googleapis/google/spannerlib || true
-cp -r google/spannerlib googleapis/google/spannerlib
+ln -sf "${PWD}"/google/spannerlib googleapis/google/spannerlib
 cd googleapis || exit 1
 protoc \
   --go_out=../ \
@@ -15,4 +14,4 @@ protoc \
   --java-grpc_opt=paths=source_relative \
   google/spannerlib/v1/spannerlib.proto
 cd .. || exit 1
-rm -rf googleapis/google/spannerlib
+rm googleapis/google/spannerlib