grpc-swift/Sources/Examples/Echo

Echo, a gRPC Sample App

This directory contains a simple echo server that demonstrates all four gRPC API styles (Unary, Server Streaming, Client Streaming, and Bidirectional Streaming) using the gRPC Swift.

There are four subdirectories:

• Model/ containing the service and model definitions and generated code,
• Implementation/ containing the server implementation of the generated model,
• Runtime/ containing a CLI for the server and client using the NIO-based APIs.
• AsyncAwaitRuntime/ containing a CLI for the server and client using the async-await–based APIs.

CLI implementation

The SwiftPM targets for the NIO-based CLI and the async-await–based CLI are Echo and AsyncAwaitEcho respectively.

The below examples make use the former, with commands of the form:

swift run Echo ...

To use the CLI using the async-await APIs, replace these commands with:

swift run AsyncAwaitEcho ...

Server

To start the server run:

swift run Echo server

By default the server listens on port 1234. The port may also be specified by passing the --port option. Other options may be found by running:

swift run Echo server --help

Client

To invoke the 'get' (unary) RPC with the message "Hello, World!" against the server:

swift run Echo client "Hello, World!"

Different RPC types can be called using the --rpc flag (which defaults to 'get'):

• 'get': a unary RPC; one request and one response
• 'collect': a client streaming RPC; multiple requests and one response
• 'expand': a server streaming RPC; one request and multiple responses
• 'update': a bidirectional streaming RPC; multiple requests and multiple responses

Additional options may be found by running:

swift run Echo client --help