agnostic-visualization

README

Agnostic Visualization

Basically, it is a canvas drawing grpc api with persistent storage of scenes.

Current deployment is located here: http://nilserver.dynv6.net:6900

Server general description

This includes 4 components (or services as per docker-compose config):

1. nginx_static:

Code is located under server/frontend. As it says in the name, it's the basic nginx static file server. Static files include grpc-web client.

2. grpc_proxy

Code (just a config file actually) located under server/grpc_proxy. Envoy proxy that forwards grpc-web requests to backend service. It is needed to translate http/1.1 traffic to http/2, which is used by grpc. For more info, look here.

3. av_server

Code is located under server/. Main grpc service with all handlers. For persistence it stores drawings in mongodb.

4. mongo

No code here, just latest mongodb docker image. Everything is stored in database named Visualization. Scene info (mainly, authenticator) is stored in scenes collection. Drawings are stored in drawings collection (what a surprise).

How to (re)build and run

1. Generate grpc and pb files from .proto using generate.sh (it's just a shorthand for 3 calls to protoc):

$ ./generate.sh

1. Run docker-compose with build option:

$ docker-compose up --build

All build operations (frontend packing and main server binary building) are performed during multistage build of the respective images. See their Dockerfiles for more info on building.

Deployment

If you want to deploy this for yourself, keep in mind that it requires 2 open (or forwarded) ports to work: 6900 (for static files) and 6901 (for grpc).

Client

There is also a small client that can be used as console util for grpc api. It was used only for testing.

API Usage

• Create new scene using Register method, it returns SceneId and Authenticator. All scene-modifying requests require Authenticator.
• Add drawings using Draw method, it returns DrawingId.
• Remove drawings by DrawingId using Remove method.
• Remove all drawings on a scene using Clear method.
• Remove scene completely using Delist method.
• Poll for scene updates using Poll method. AfterTimestamp parameter is used for pagination, it should be updated on client after receiving new batch of drawings. Currently used on website to draw on canvas, but can be used with other drawing software.