Proximo 
Proximo is a proxy for multiple different publish-subscribe queuing systems.
It is based on a GRPC interface definition, making it easy to create new client libraries. It already supports a number of popular queueing systems, and adding new ones is intended to be simple.
Goals
-
Expose multiple consumer (fan out) semantics where needed
-
Minimise overhead over direct use of a given queuing system
-
Allow configuration of the underlying queue system via runtime configuration of Proximo
-
Allow replacement of a queueing system with no change to the Proximo client applications
-
Enabling easy creation of client libraries for new languages (anything that has GRPC support)
Non goals
- Exposing specific details of the underlying queue system via the client API
Server
This is the Proximo server implementation, written in Go
Proximo client libraries
- go - substrate - we recommend to use substrate to access proximo from go
API definition (protobuf)
Access Control
Access Control is supported using an optional config file, using the PROXIMO_ACL_CONFIG.
In this example, all clients can access the topics that start with products but only a client called
product-writer has permission to to write to these topics.
default:
roles: ["read-products"]
roles:
- id: "read-products"
consume: ["products.*"]
- id: "write-products"
publish: ["products.*"]
clients:
- id: "product-writer"
secret: "$2y$10$2AzC3Z8L18cP.crFi.ZDsuFdbwrYu16Lnh8y7U1wMO3QPanYuwJIm" # pass is bcrypted hash of "password"
roles: ["write-products"]Add the token to the context, example:
sink, _ := proximo.NewAsyncMessageSink(proximo.AsyncMessageSinkConfig{
Broker: "localhost:6868",
Topic: "products",
Insecure: true,
})
token := base64.StdEncoding.EncodeToString(fmt.Sprintf("%s:%s", "product-writer", "password"))
md := metadata.Pairs("Authorization", fmt.Sprintf("Bearer %s", token))
reqCtx := metadata.NewOutgoingContext(ctx, md)
sink.PublishMessage(reqCtx, &Message{Data: []byte("hello world")})