Planet Express

You are contracted to refactor Professor Farnsworth's legacy client/server code, and you decide to spice weasel (BAM!) things up with K8s, gRPC, and GraphQL. The professor wants to run a gateway service at the Planet Express headquarters that can communicate with Planet Express ship via gRPC. Furthermore, he wants a nice React UI to show data about the ship, deliveries, crew members, etc that will communicate with the gateway service via GraphQL.

In this architecture the ship is a backend service, the headquarters is a api gateway, and the frontend is a React SPA.

Setup

When you are done shopping for lightspeed briefs you decide to setup the new project. You realize that some of it is already set up for you. The ./headquarters directory contains the gateway/client code and the ./ship directory contains the server code.

1. Create a gitlab repo called planet-express
2. Setup Your Dev Environment
   • Install go (https://golang.org/doc/install)
   • Install protoc (https://grpc.io/docs/protoc-installation/)
   • Follow the getting started guide to install the protoc go plugin (https://grpc.io/docs/languages/go/quickstart/)
3. go get google.golang.org/grpc
4. go get github.com/golang/protobuf
5. Copy the files in this repo over to your new repo
6. Run go mod init gitlab.com/<gitlab-username>/planet-express
7. Your go mod should look something like the included _go.mod file (delete this file when done)
8. Fix the import statements in ./ship/main.go and ./headquarters/main.go (the lines commented like so // pb "gitlab.com/<gitlab-username>/planet-express/ship/pkg/planetexpress")
9. Validate that you can build and genarate go code by running make
10. Validate you have the executables ./ship/ship and ./headquarters/headquarters
11. Run the server ./ship/ship and the client ./headquarters/headquarters in separate terminal windows and confirm the output.

Generate Go Code

The protoc compiler with the go plugin will autogenerate client and server grpc stubs for you. Make sure this runs successfully with make

You should try changing the protobuf files in ./proto and re-run make. The generated files are put in ./ship/pkg/planetexpress and ./headquarters/pkg/planetexpress

Build

A makefile has been provided for you that will generate go code with the protoc compiler and build the executables. Run make and validate that you have executables at ./ship/ship and ./headquarters/headquarters

Your Assignment

Time Estimate: 3 hours

The basic client and server code has been provided for you. Your job is to do the following:

1. Implement crew.proto and delivery.proto and the functions listed in planet_express_service.proto
   • You should experiment with different protobuf types for the crew and delivery resources. Each resource should demonstrate an understanding of protobuf.
2. Refactor ship.proto to use the crew and delivery resources.
3. Implement the rpc functions (defined in planet_express_service.proto) in both the client (./headquarters) and server (./ship), following the GetShip example. You do not need to add a database. Experiment with using data contained in the gRPC request.
4. Output data about the planet express ship, deliveries, and crew members to a json file called planet_express.json. Feel free to get creative with your data and protobuf resources.
5. Add a dockerfile to ./ship so that we can run the server with docker.

Above and Beyond

Time Estimate: 4 hours

1. Provide a basic helm template for the ./ship server. This should contain a kubernetes deployment and service. We should be able to port-forward your service to call the ./ship rpc functions.
2. Add additional protobuf resources like ShipEngine. You can get creative with this.
3. Add graphql support to the api gateway (headquarters). A good library for this is https://github.com/graph-gophers/graphql-go. Map a graphql endpoint/resource to a gRPC call, like for GetShip. A GraphQL client should be able to query data from the headquarters which in turn resolves the query by getting data from the ship backend via gRPC.

Bite my shiny metal a$$ (extra, extra)

Time Estimate: 4 hours

1. Add a simple React SPA that displays data about the ship using GraphQL to communicate with the gateway (headquarters service). You can put this in the ./dashboard directory.
2. Add some go unit tests to the ship server.

** These would really impress us here at Planet Express! **

Deliverables

Make your repository public and share the repo url with Divvy's recruiter.

Helpful Resources

• https://grpc.io/docs/languages/go/quickstart/
• https://grpc.io/docs/languages/go/basics/
• https://cloud.google.com/apis/design
• https://github.com/graph-gophers/graphql-go
• https://reactjs.org/docs/create-a-new-react-app.html

Questions

If you find errors or otherwise need clarification on anything in the excercise, please reach out to Justin Sharp justin.sharp@divvypay.com.