Workflow-engine should be just another Fission environment

[erwinvaneyk]

Currently the workflow-engine, due to prototyping reasons, is a separate component within the fission ecosystem. The plan is to ensure that the workflow engine is just another environment.

The benefits of it being a environment:

• It will be there for users actually using it.
• No need for users to go out and deploy it manually. Just add the environment like any other and you are done.
• Make use of the existing functionality provided to environments. e.g. autoscaling.

To achieve this

• A option is needed in Fission that allows environments to specify the maximum number of instances needed and whether it can specialize multiple functions. Currently Fission always maintains at least 3 environment instances and allows only one specialization per instance.
• Add a fetcher to the system that corresponds, similar to the fetcher used in other environments.
• A specialize endpoint needs to be added to the Fission Proxy.
• Functionality should be added to Fission to allow for gRPC communication (again, based on an option of the environment). This will allow us to also merge the Fission Proxy into the existing gRPC server, removing the need for an additional server (as is the situation now)

[erwinvaneyk]

It is!