gomgo

README

gomgo

Gomgo is a toy http json api server powered by Golang and MongoDB and ZeroMQ. It does not use magic or not magic framework, but just Idiomatic HTTP Middleware and some Best Practices for Golang, e.g. middleware chain, error handling, jwt token. I use it as a micro project template myself.

Run server

1 Install Go and set up your GOPATH, then install MongoDB and run it

2 Install Go package

go get github.com/gorilla/mux
go get github.com/justinas/alice
go get github.com/stretchr/graceful
go get github.com/PuerkitoBio/throttled
go get github.com/PuerkitoBio/throttled/store
go get gopkg.in/mgo.v2
go get gopkg.in/mgo.v2/bson
go get code.google.com/p/go.crypto/bcrypt
go get github.com/dgrijalva/jwt-go
go get code.google.com/p/go.net/context
go get github.com/pebbe/zmq4

3 Get this code

go get github.com/fengjian0106/gomgo

4 Build

sh build.sh

5 Run the server

./gomgo

You will now have a Go net/http webserver running on localhost:3000.

Request the server

Use curl to make http request

1 Register new user

curl -v -X POST -H 'Content-Type: application/json' \
     -d '{"email": "helloworld@gmai.com", "password": "123456", "name": "helloworld"}' \
     http://127.0.0.1:8080/api/users

2 Login

curl -v -X POST -H 'Content-Type: application/json'  \
     -d '{"email": "helloworld@gmai.com", "password": "123456"}'  \
     http://127.0.0.1:8080/api/signin

After login, you will get response like below

{"userId":"53e49b07c3666ed09d000001","token":"eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJQYWRkaW5nIjoie1wiaWRcIjpcIjUzZTQ5YjA3YzM2NjZlZDA5ZDAwMDAwMVwiLFwibmFtZVwiOlwiaGVsbG93b3JsZFwifSIsIlRva2VuVHlwZSI6IkFjY2Vzc1Rva2VuIiwiZXhwIjoxNDEwMDgyOTU0fQ.XN8OsZJKzv0HdloP-6T53PY4eOA8v59zBeIf_-6F0lRAoUqGpT6kgyuisaDlDDU_KkFiubOS2Akg0lj_sls7XkJJCR5sDgCHV9pRAhK41c9OEvq1OmJl0uxbOh22WOtbTLtyi_H6rS5Rxe3lOiL7dS539uLgBTzQshnXxXEWnQVKTFbJB2DitVnZNuAZTEKxjp1sbXBsLWDQ3IdfVwHRY8gX2g5f44QMBx83Qd-yvf0kIv-_bBugX7LXzruihKI8-caUsuaDAi--MoAqmVVsTHCImJvLjyZIhMqaRZSry48qo4NPCgUqoZOSQ9QkxQ0N1jWuGL9ahAL5Wgr5qzwv9g"}

Copy userId and token, later we will use it

3 Create a blog post
Use userId and token you copied in last step

curl -v -X POST -H 'Content-Type: application/json'  \
     -H "Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJQYWRkaW5nIjoie1wiaWRcIjpcIjUzZTQ5YjA3YzM2NjZlZDA5ZDAwMDAwMVwiLFwibmFtZVwiOlwiaGVsbG93b3JsZFwifSIsIlRva2VuVHlwZSI6IkFjY2Vzc1Rva2VuIiwiZXhwIjoxNDEwMDgyOTU0fQ.XN8OsZJKzv0HdloP-6T53PY4eOA8v59zBeIf_-6F0lRAoUqGpT6kgyuisaDlDDU_KkFiubOS2Akg0lj_sls7XkJJCR5sDgCHV9pRAhK41c9OEvq1OmJl0uxbOh22WOtbTLtyi_H6rS5Rxe3lOiL7dS539uLgBTzQshnXxXEWnQVKTFbJB2DitVnZNuAZTEKxjp1sbXBsLWDQ3IdfVwHRY8gX2g5f44QMBx83Qd-yvf0kIv-_bBugX7LXzruihKI8-caUsuaDAi--MoAqmVVsTHCImJvLjyZIhMqaRZSry48qo4NPCgUqoZOSQ9QkxQ0N1jWuGL9ahAL5Wgr5qzwv9g" \
     -d '{"from": {"id": "53e49b07c3666ed09d000001"}, "message": "this is the first blog, hello world"}'  \
     http://127.0.0.1:8080/api/users/53e49b07c3666ed09d000001/posts

If you post blog success, you will get response like below

{"postId": "53e49e68c3666ed09d000002"}

Copy postId, later we will use it

4 Create a comment for a blog
Normal, somebody else will create a comment for your post. Inorder to demonstrate this, you need register another user, and repeat step <1> and <2>, then you will get a new pair of userId and token. Copy them, also copy the postId you get in step <3>, we will use them

curl -v -X POST -H 'Content-Type: application/json'  \
     -H "Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJQYWRkaW5nIjoie1wiaWRcIjpcIjUzZTRhMWU1YzM2NjZlZDA5ZDAwMDAwM1wiLFwibmFtZVwiOlwibmV3b25lXCJ9IiwiVG9rZW5UeXBlIjoiQWNjZXNzVG9rZW4iLCJleHAiOjE0MTAwODQ2NjZ9.lKGbdz6zYu5aXpk2Xq5JLYfcBG4kpD5Wa7NiExSQYddtawX_5rosAFsFzD-mNbmR79Ymtt8j22kuw-mC1vZbCx6BCgMtqtb9X3Q7pvEKZ-46WKSJ5E2sHGNZ3YZa-iTYIf4CD0_LmWeHT5UPm3MWYo14Hf-tr6sLUeovmp7NuXj0x-pJDogSJ815NctoWFHXVTcTwffd52WaPptQjeryisROo1qbtmjPAAgdXKFBDWiwe2nrzG4erpbxOiGAOy9CT5rUhMiqlCKC-FGhc4UZ9GQ6pnzbv72-5uQqfiEJc3EWSuSbuyrNa-CAHDapr90SN3j3hLrE45PNVpQxotubFg" \
     -d '{"from":{"id": "53e4a1e5c3666ed09d000003"}, "message": "this is comment from other user"}'  \
     http://127.0.0.1:8080/api/posts/53e49e68c3666ed09d000002/comments

If you post comment success, you will get response like below

{"postId": "53e49e68c3666ed09d000002", "commentId": "53e4a25bc3666ed09d000004"}

5 Get the post
Everyone can get post by the postId, so let's use the new token received in step <4> to get the post with the postId received in step <3>

curl -v --compressed -X GET -H 'Content-Type: application/json'  \
     -H "Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJQYWRkaW5nIjoie1wiaWRcIjpcIjUzZTRhMWU1YzM2NjZlZDA5ZDAwMDAwM1wiLFwibmFtZVwiOlwibmV3b25lXCJ9IiwiVG9rZW5UeXBlIjoiQWNjZXNzVG9rZW4iLCJleHAiOjE0MTAwODQ2NjZ9.lKGbdz6zYu5aXpk2Xq5JLYfcBG4kpD5Wa7NiExSQYddtawX_5rosAFsFzD-mNbmR79Ymtt8j22kuw-mC1vZbCx6BCgMtqtb9X3Q7pvEKZ-46WKSJ5E2sHGNZ3YZa-iTYIf4CD0_LmWeHT5UPm3MWYo14Hf-tr6sLUeovmp7NuXj0x-pJDogSJ815NctoWFHXVTcTwffd52WaPptQjeryisROo1qbtmjPAAgdXKFBDWiwe2nrzG4erpbxOiGAOy9CT5rUhMiqlCKC-FGhc4UZ9GQ6pnzbv72-5uQqfiEJc3EWSuSbuyrNa-CAHDapr90SN3j3hLrE45PNVpQxotubFg" \
     http://127.0.0.1:8080/api/posts/53e49e68c3666ed09d000002

If everything is ok, you will get response like below

{"id":"53e49e68c3666ed09d000002","from":{"id":"53e49b07c3666ed09d000001","name":"helloworld"},"Message":"this is the first blog, hello world","CreatedTime":"2014-08-08T17:54:48.317+08:00","UpdatedTime":"2014-08-08T17:54:48.317+08:00","Comments":[{"id":"53e4a25bc3666ed09d000004","From":{"id":"53e4a1e5c3666ed09d000003","name":"newone"},"Message":"this is comment from other user","CreatedTime":"2014-08-08T18:11:39.752+08:00"}]}

Distributed Systems

Distributed Systems is interesting. I will also try to show some basic technique on how to implement it.

1 RPC
Path "/api/search?q=xxx&timeout=1s" do a google search, and the handler call a remote REST service (If you want a RPC, the code will be same the like)

You can test it like below, using keyword "golang"

curl -v --compressed -X GET -H 'Content-Type: application/json' http://127.0.0.1:8080/api/search?q=golang&timeout=2s

And if success, you will get response like below

{"data":[{"title":"The Go Programming Language","url":"http://golang.org/"},{"title":"A Tour of Go","url":"http://tour.golang.org/"},{"title":"Downloads - The Go Programming Language","url":"http://golang.org/dl/"},{"title":"Go (programming language) - Wikipedia, the free encyclopedia","url":"http://en.wikipedia.org/wiki/Go_(programming_language)"}],"elapsedSeconds":3.29384076}

2 ZeroMQ
Path "/api/zmp?msg=xxx" send a request and get a reply. And the architecture is shown as below

+-----------------------------------+                                                                                                            
|                                   |                                                                                                            
|  +----------+       +----------+  |                                                                                                            
|  |ZMQHandler|  ...  |ZMQHandler|  |                                                                                                            
|  +----------+       +----------+  |                                                                                                            
|                                   |                                                                                                            
|       ^                  ^        |                                                                                                            
|       |       gomgo      |        |                                                                                                            
|       |                  |        |                                                                                                            
|       v                  v        |                                     +--------+                                                             
|                                   |                                +--> | worker |                                                             
|     +----------------------+      |                                |    +--------+                                                             
|     |     go msgQueue()    |  <-------+      +---------------+     |                                                                           
|     +----------------------+      |   |      |               | <---+                                                                           
|                                   |   +----> |               |                                                                     
+-----------------------------------+          |  reqRepBroker |            ......                                                          
                                        +----> |               |                                                                      
                                        |      |               | <---+                                                                           
               ......                   |      +---------------+     |                                                                           
                                        |                            |    +--------+                                                             
                                        |                            +--> | worker |                                                             
+-----------------------------------+   |                                 +--------+                                                             
|              client               | <-+                                                                                                        
+-----------------------------------+                                                                                      

Enter the dir zmqReqRepBrokerServer/nodejs-server, and install node.js dependency

npm install

After run gomgo, you should also run ONLY ONE zeromq reqRepBroker

node reqRepBroker.js

And run ONE or MANY zeromq worker

node worker.js

And optional, you can run ONE or MANY zeromq client

node client.js

Finally, it's time to test it with curl

curl -v --compressed -X GET -H 'Content-Type: application/json' http://127.0.0.1:8080/api/zmq?msg=helloworld

And if success, you will get response like below

{"retMsg": "node.js server [81043] echo: helloworld [1]"}

Thank these guys and their articles!

http://www.alexedwards.net/blog/a-recap-of-request-handling

http://capotej.com/blog/2013/10/07/golang-http-handlers-as-middleware/

http://justinas.org/writing-http-middleware-in-go/

http://justinas.org/alice-painless-middleware-chaining-for-go/

http://elithrar.github.io/article/custom-handlers-avoiding-globals/

Go Concurrency Patterns: Context

http://angular-tips.com/blog/2014/05/json-web-tokens-introduction/

http://www.vinaysahni.com/best-practices-for-a-pragmatic-restful-api

https://github.com/soygul/koan

License

MIT