This repository contains a gRPC Swift API and code generator.
It is intended for use with Apple's SwiftProtobuf support for
Protocol Buffers. Both projects contain code generation plugins for protoc,
Google's Protocol Buffer compiler, and both contain libraries of supporting code
that is needed to build and run the generated code.
APIs and generated code is provided for both gRPC clients and servers, and can be built either with Xcode or the Swift Package Manager. Support is provided for all four gRPC API styles (Unary, Server Streaming, Client Streaming, and Bidirectional Streaming) and connections can be made either over secure (TLS) or insecure channels.
gRPC Swift has recently been rewritten on top of SwiftNIO as opposed to the core library provided by the gRPC project.
| Version | Implementation | Branch | protoc Plugin |
Support |
|---|---|---|---|---|
| 1.x | SwiftNIO | main |
protoc-gen-grpc-swift |
Actively developed and supported |
| 0.x | gRPC C library | cgrpc |
protoc-gen-swiftgrpc |
No longer developed; security fixes only |
The remainder of this README refers to the 1.x version of gRPC Swift.
gRPC Swift's platform support is identical to the platform support of Swift NIO.
The earliest supported version of Swift for gRPC Swift releases are as follows:
| gRPC Swift Version | Earliest Swift Version |
|---|---|
1.0.0 ..< 1.8.0 |
5.2 |
1.8.0 ..< 1.11.0 |
5.4 |
1.11.0..< 1.16.0. |
5.5 |
1.16.0..< 1.20.0 |
5.6 |
1.20.0..< 1.22.0 |
5.7 |
1.22.0... |
5.8 |
Versions of clients and services which are use Swift's Concurrency support are available from gRPC Swift 1.8.0 and require Swift 5.6 and newer.
There are two parts to gRPC Swift: the gRPC library and an API code generator.
The Swift Package Manager is the preferred way to get gRPC Swift. Simply add the
package dependency to your Package.swift:
dependencies: [
.package(url: "https://github.com/grpc/grpc-swift.git", from: "1.21.0")
]...and depend on "GRPC" in the necessary targets:
.target(
name: ...,
dependencies: [.product(name: "GRPC", package: "grpc-swift")]
]Binary releases of protoc, the Protocol Buffer Compiler, are available on
GitHub.
To build the plugins, run:
swift build -c release --product protoc-gen-swiftto build theprotocplugin which generates Protocol Buffer support code, andswift build -c release --product protoc-gen-grpc-swiftto build theprotocplugin which generates gRPC interface code.
To install these plugins, just copy the two executables (protoc-gen-swift and
protoc-gen-grpc-swift) from the build directory (.build/release) into a directory
that is part of your PATH environment variable. Alternatively the full path to
the plugins can be specified when using protoc.
You can also use the Swift Package Manager build plugin to generate messages and
gRPC code at build time rather than using protoc to generate them ahead of
time. Using this method Swift Package Manager takes care of building
protoc-gen-swift and protoc-gen-grpc-swift for you.
One important distinction between using the Swift Package Manager build plugin
and generating the code ahead of time is that the build plugin has an implicit
dependency on protoc. It's therefore unsuitable for libraries as they can't
guarantee that end users will have protoc available at compile time.
You can find more documentation about the Swift Package Manager build plugin in Using the Swift Package Manager plugin.
gRPC Swift has a number of tutorials and examples available. They are split across two directories:
/Sources/Examplescontains examples which do not require additional dependencies and may be built using the Swift Package Manager./Examplescontains examples which rely on external dependencies or may not be built by the Swift Package Manager (such as an iOS app).
Some of the examples are accompanied by tutorials, including:
- A quick start guide for creating and running your first gRPC service.
- A basic tutorial covering the creation and implementation of a gRPC service using all four call types as well as the code required to setup and run a server and make calls to it using a generated client.
- An interceptors tutorial covering how to create and use interceptors with gRPC Swift.
The docs directory contains documentation, including:
- Options for the
protocplugin indocs/plugin.md - How to configure TLS in
docs/tls.md - How to configure keepalive in
docs/keepalive.md - Support for Apple Platforms and NIO Transport Services in
docs/apple-platforms.md
Benchmarks for grpc-swift are in a separate Swift Package in the Performance/Benchmarks subfolder of this repository.
They use the package-benchmark plugin.
Benchmarks depends on the jemalloc memory allocation library, which is used by package-benchmark to capture memory allocation statistics.
An installation guide can be found in the Getting Started article of package-benchmark.
Afterwards you can run the benchmarks from CLI by going to the Performance/Benchmarks subfolder (e.g. cd Performance/Benchmarks) and invoking:
swift package benchmark
Profiling benchmarks or building the benchmarks in release mode in Xcode with jemalloc is currently not supported and requires disabling jemalloc.
Make sure Xcode is closed and then open it from the CLI with the BENCHMARK_DISABLE_JEMALLOC=true environment variable set e.g.:
BENCHMARK_DISABLE_JEMALLOC=true xed .
For more information please refer to swift package benchmark --help or the documentation of package-benchmark.
Please see SECURITY.md.
gRPC Swift is released under the same license as gRPC, repeated in LICENSE.
Please get involved! See our guidelines for contributing.