tacodata/abroute-docker-autobahn repository overview

⁠abroute_docker_autobahn - autobahn scripts

These are the scripts that run autobahn proof of concept There are 3 of them, they are meant to be run in separate containers.

⁠Overview

There are two main scripts and one utility script.

• router, this is the main autobahn router with a couple of hooks to do authorization and authentication
• rpc, these are the main functions for doing authentication and authorization
• adm, this is simply the admin utility, like adding topics or users or roles. monitoring activity. etc.

Autobahn provides for registering functions with a name, and calling them remotely as well as publish / subscribe functionality. This code is based upon the concept that the names that are registered with Autobahn (topics) are logical domains. They are dot separated subjects. E.g. com is the logical parent of com.devices which in turn is the logical parent of com.devices.fan. Using this heirchy, We can map permissions on top to control the actions we can take on the topic. The actions that can be controlled are

• register - register a function
• call - call an already registered function
• publish - publish a message to a topic
• subscribe - subscribe to a topic channel
• admin - grant these actions / permissions to others

A hook is needed in the autobahn router to check authentication and authorization. Luckily, there is already a hook for authentication. Authorization needs to be checked before doing each action, that is why I needed to modify the router a little bit, to put in this authorization. After I wrote this code the Autobahn project removed router functionality from the code and moved it to a different project (Crossbar). That's why this code is on an older version of Autobahn.

The router has a dependency on the database. The database should be listening at pg (hostname pg) port 5432. The router will in turn listen on port 8080 for web socket connections from clients.

To start the router:

docker run -d -name ab tacodata/abroute_docker_autobahn router

The router has a companion process it needs. I could put it in the same process, but, I am exercising docker orchestration which makes me want to have additional processes :-) To start the supporting rpc:

docker run -d -name rpc tacodata/abroute_docker_autobahn rpc

The supporting rpc looks for the router at ab:8080.

The hostnames are populated by a discovery mechanism. Docker-compose puts these into the /etc/hosts file when starting containers based upon the links section. Hostname can also be populated using the registrator/skydns mechanism, which populates dns based upon containers starting/stopping. I plan on testing both of these methods.

⁠Docker Container Layout

The containers in this repo are indicated by sqlauthroute and sqlauthrpc in the drawing. The rpc container has no public interfaces. It is a part of the router. The router itself has a single public interface, currently 8080, which web socket connections are made with. The router is stateless. All of the state is held in the postgres database.

⁠Scalability

With the version of Autobahn I am running I cannot connect routers to each other. So, with this architecture the only thing that can be replicated is the rpc container. If the router is the bottleneck, then to replicate that will take a little work to push calls and publishes through the database, and let it communicate with the other routers. If postgres turns out to be the bottleneck we can device a scheme to mave one master and many replicated slaves (for read queries).

All that said, this framework is not the ultimate application. This framework mearly puts in place authentication and authorization for the application. I am guessing that the framework should handle millions of account histories, and perhaps tens of thousands of active accounts.