gRPC: a REAL beginners guide

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gRPC beginners guide.md

Compiler

The protoc compiler is written in C++ and needs to be built from source:

Note: here details shell dependencies required

• git clone git@github.com:google/protobuf.git
• ./autogen.sh
• ./configure
• make # this can take quite a while ~10 mins for me
• make check # this can take quite a while ~10 mins for me
• sudo make install

Go Example

• go get -a github.com/golang/protobuf/protoc-gen-go (Go plugin for protoc compiler)
• git clone https://github.com/grpc/grpc.git
• cd grpc/examples
• mkdir testing-helloworld
• protoc -I ./protos ./protos/helloworld.proto --go_out=plugins=grpc:testing-helloworld

This generates:

testing-helloworld/
└── helloworld.pb.go

0 directories, 1 file

• go get -u google.golang.org/grpc/examples/helloworld/greeter_client
• go get -u google.golang.org/grpc/examples/helloworld/greeter_server
• cd $GOPATH/src/google.golang.org/grpc/examples/helloworld
• cd greeter_server & go run main.go
• cd greeter_client & go run main.go

Note: the client/server you downloaded reference their own pb.go
/src/google.golang.org/grpc/examples/helloworld/helloworld/helloworld.pb.go
If you want, you can create your own client/server code to be sure…

• cd grpc/examples (wherever you originally git cloned the grpc repo)
• cp greeter_server.go ./testing-server.go

Replace the line:

pb "google.golang.org/grpc/examples/helloworld/helloworld"

With:

pb "github.com/wherever/you/cloned/grpc/examples/testing-helloworld"

Now you should be able to run:

go run testing-server.go

And verify using either the existing Go client you downloaded (see above) or an existing Ruby client (see below).

Ruby Example

• git clone https://github.com/grpc/grpc.git
• cd grpc/examples/ruby
• bundle install (includes install of Ruby plugin for protoc)
• bundle exec ./greeter_server.rb
• bundle exec ./greeter_client.rb

Mixing Server and Client

You can mix and match servers and clients.

e.g. have a Go server running with a Ruby client connecting, and vice versa

Custom Services

You’ll find that if you want to write your own proto files and compile them, having the protoc compiler itself is not enough. You also need to build grpc (https://github.com/grpc/grpc/blob/master/INSTALL.md) from source too :-/

• git clone https://github.com/grpc/grpc.git
• cd grpc
• git submodule update --init
• make
• make install