gRPC-gateway Example

Directory Structure

• api: A basic REST gateway, forwarding requests onto service(s).
• racing: A very bare-bones racing service.
• sports: A very bare-bones sports service.

grpc-gateway/
├─ api/
│  ├─ proto/
│  ├─ main.go
├─ racing/
│  ├─ db/
│  ├─ proto/
│  ├─ service/
│  ├─ main.go
├─ sports/
│  ├─ db/
│  ├─ proto/
│  ├─ service/
│  ├─ main.go
├─ README.md

Getting Started

1. Install Go (latest).

brew install go

... or see here.

2. Install protoc

brew install protobuf

... or see here.

2. In a terminal window, start our racing service...

cd ./racing

go build && ./racing
➜ INFO[0000] gRPC server listening on: localhost:9000

3. In another terminal window, start our api service...

cd ./api

go build && ./api
➜ INFO[0000] API server listening on: localhost:8000

4. Make a request for races...

curl -X "POST" "http://localhost:8000/v1/list-races" \
     -H 'Content-Type: application/json' \
     -d $'{
  "filter": {}
}'

5. Make a request for list-races filter with visible.

curl -X POST 'http://localhost:8000/v1/list-races' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true
    }
}'

6. Make a request for visible and meeting_ids

curl -X POST 'http://localhost:8000/v1/list-races' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "meeting_ids": [3,8]
    }
}'

7. Make a request for order by advertised_start_time asc

curl -X POST 'http://localhost:8000/v1/list-races' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "column":"advertised_start_time",
        "order_by": "asc"
    }
}'

8. Make a request for order by advertised_start_time desc, with a new field status, all data status is CLOSED.

curl -X POST 'http://localhost:8000/v1/list-races' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "column":"advertised_start_time",
        "order_by": "desc"
    }
}'

9. Make a request for get the race by id

curl -X GET 'http://localhost:8000/v1/race?id=57' \
-H 'Content-Type: application/json'

10. In another terminal window, start the new sports service...

cd ./sports

go build && ./sports
➜ INFO[0000] API server listening on: localhost:9002

11. Make a request for get the list-events filter visible and advertised_start_time asc

curl -X POST 'http://localhost:8000/v1/list-events' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "column":"advertised_start_time",
        "order_by": "asc"
    }
}'

12. Make a request for get the list-events filter visible and start_time desc

curl -X POST 'http://localhost:8000/v1/list-events' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "column":"start_time",
        "order_by": "desc"
    }
}'

13. Make a request for get the list-events filter visible and name desc

curl -X POST 'http://localhost:8000/v1/list-events' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "column":"name",
        "order_by": "desc"
    }
}'

14. Make a request for get the list-events with filter event id and visible

curl -X POST 'http://localhost:8000/v1/list-events' \
-H 'Content-Type: application/json' \
-d $'{
    "filter": {
        "visible":true,
        "id":68
    }
}'

15. In the terminal, go to racing/service or sports/service, run unittests

cd ./racing/service

go test . -v

cd ./sports/service

go test . -v

Changes/Updates Required

• We'd like to see you push this repository up to GitHub/Gitlab/Bitbucket and lodge a Pull/Merge Request for each of the below tasks.
• This means, we'd end up with 5x PR's in total. Each PR should target the previous, so they build on one-another.
• Alternatively you can merge each PR/MR after each other into master.
• This will allow us to review your changes as well as we possibly can.
• As your code will be reviewed by multiple people, it's preferred if the repository is publicly accessible.
• If making the repository public is not possible; you may choose to create a separate account or ask us for multiple email addresses which you can then add as viewers.

... and now to the test! Please complete the following tasks.

1. Add another filter to the existing RPC, so we can call ListRaces asking for races that are visible only.

   We'd like to continue to be able to fetch all races regardless of their visibility, so try naming your filter as logically as possible. https://cloud.google.com/apis/design/standard_methods#list

2. We'd like to see the races returned, ordered by their advertised_start_time

   Bonus points if you allow the consumer to specify an ORDER/SORT-BY they might be after.

3. Our races require a new status field that is derived based on their advertised_start_time's. The status is simply, OPEN or CLOSED. All races that have an advertised_start_time in the past should reflect CLOSED.

   There's a number of ways this could be implemented. Just have a go!

4. Introduce a new RPC, that allows us to fetch a single race by its ID.

   This link here might help you on your way: https://cloud.google.com/apis/design/standard_methods#get

5. Create a sports service that for sake of simplicity, implements a similar API to racing. This sports API can be called ListEvents. We'll leave it up to you to determine what you might think a sports event is made up off, but it should at minimum have an id, a name and an advertised_start_time.

Note: this should be a separate service, not bolted onto the existing racing service. At an extremely high-level, the diagram below attempts to provide a visual representation showing the separation of services needed and flow of requests.

Don't forget:

Document and comment! Please make sure your work is appropriately documented/commented, so fellow developers know whats going on.

Note:

To aid in proto generation following any changes, you can run go generate ./... from api and racing directories.

Before you do so, please ensure you have the following installed. You can simply run the following command below in each of api and racing directories.

go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2 google.golang.org/genproto/googleapis/api google.golang.org/grpc/cmd/protoc-gen-go-grpc google.golang.org/protobuf/cmd/protoc-gen-go

Good Reading

• Protocol Buffers
• Google API Design
• Go Modules
• Ubers Go Style Guide