gRPC [Golang] tutorial

This is an implementation of Udemy tutorial

1. install GO:

    $ wget https://dl.google.com/go/go1.12.9.linux-amd64.tar.gz
    $ sudo tar -C /usr/local -xzf go1.12.9.linux-amd64.tar.gz
    $ export PATH=$PATH:/usr/local/go/bin
   

2. Install grpc-go:

    $ go get -u google.golang.org/grpc
   

3. Install Protocol Buffers for GO:

    $ go get -u github.com/golang/protobuf/protoc-gen-go
   

4. Install Protocol Buffers (protoc)

    $ curl -OL https://github.com/protocolbuffers/protobuf/releases/download/v3.9.1/protoc-3.9.1-linux-x86_64.zip
    $ unzip protoc-3.9.1-linux-x86_64.zip -d protoc3
    $ sudo mv protoc3/bin/* /usr/local/bin/ && sudo mv protoc3/include/* /usr/local/include/
    $ rm protoc-3.9.1-linux-x86_64.zip && rm -rf protoc3
   

Greeting example

1. Compile .proto file to .go file:

    $ protoc greet/greetpb/greet.proto --go_out=plugins=grpc:.
   

2. Run greet server:

    $ go run greet/greet_server/server.go
   

3. Run greet client:

    $ go run greet/greet_client/client.go
   

Calculator example

1. Compile .proto file to .go file:

    $ protoc calculator/calculatorpb/calculator.proto --go_out=plugins=grpc:.
   

2. Run calculator server:

    $ go run calculator/calculator_server/server.go
   

3. Run calculator client:

    $ go run calculator/calculator_client/client.go
   

(Update) How to run Sum RPC via REST:

1. Download the following packages:

    $ go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway
    $ go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
   

2. Compile .proto file to .go file:

    $ protoc -I/usr/local/include -I. \
        -I$GOPATH/src \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
        --go_out=plugins=grpc:. \
        calculator/calculatorpb/calculator.proto
   

3. Generate reverse-proxy using protoc-gen-grpc-gateway:

    $ protoc -I/usr/local/include -I. \
        -I$GOPATH/src \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
        --grpc-gateway_out=logtostderr=true:. \
        calculator/calculatorpb/calculator.proto
   

   It will generate calculator/calculatorpb/calculator.pb.gw.go file

4. (Optional) Generate swagger definitions using protoc-gen-swagger:

    $ protoc -I/usr/local/include -I. \
        -I$GOPATH/src \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
        --swagger_out=logtostderr=true:. \
        calculator/calculatorpb/calculator.proto
   

   It will generate calculator/calculatorpb/calculator.swagger.json file

5. Run calculator server:

    $ go run calculator/calculator_server/server.go
   

6. Run calculator gateway:

    $ go run calculator/calculator_server/gateway.go
   

7. Send message via curl:

    $ curl -X POST -k http://127.0.0.1:8081/sum -d '{"first_number": 5, "second_number": 3}'
   

   And you will get response {"sum_result":8} as result

SSL certificate

1. Install openssl:

    $ sudo apt-get install openssl
   

2. Create needed certificates, keys:

    $ cd ssl
    $ chmod +x ./generate_files.sh
    $ ./generate_files.sh
   

   if you got Cannot open file .rnd error - create an empty .rnd file

Blog example

1. Install MongoDB:

   • Download and install MongoDB from here

   • Create folder to store data:

       $ mkdir ~/mongodata
       $ mkdir ~/mongodata/db
     

   • Run MongoDB:

       $ /usr/bin/mongod --dbpath ~/mongodata/db
     

2. Install UI for your MongoDB:

   • Download Robo 3T from here

   • Switch to download directory and run these commands:

       $ tar -xvzf robo3t*.tar.gz
       $ sudo mkdir /usr/local/bin/robomongo
       $ sudo mv robo3t*/* /usr/local/bin/robomongo
       $ cd /usr/local/bin/robomongo/bin
       $ sudo chmod +x robo3t
     

   • Open .bashrc file:

       $ sudo vim ~/.bashrc
     

     And add the following line to the end of the file:

       alias robomongo='/usr/local/bin/robomongo/bin/robo3t'
     

   • Reload it using the following command:

       $ source ~/.bashrc
     

   • Run robomongo from your terminal:

       $ robomongo
     

3. Install MongoDB driver for Golang:

    $ go get go.mongodb.org/mongo-driver/mongo
   

Run Blog Example

1. Compile .proto file to .go file:

    $ protoc blog/blogpb/blog.proto --go_out=plugins=grpc:.
   

2. Run blog server:

    $ go run blog/blog_server/server.go
   

3. Run blog client:

    $ go run blog/blog_client/client.go