Karmen

Centralized Pub/Sub for microservices

2.0 release

• I rewrote Karmen from the ground up in July 2021. It is incompatible with version 1.0.

Enhancements

• Karmen now runs off of gRPC, which cuts down lots of nasty bugs
• if: as a key under an action is now a reserved word for conditional expressions
• parallel and serial blocks should perform how you expect...each block is done serially
• Context variables - actions can return parameters that are injected into a block-level state. These can be referenced in conditionals with {hostname-action-variablename}
  • I'll be converting the dashes to dots once I add that feature to the condition parser I used
  • For each action, the {hostname-action-pass} boolean is set automatically so you can conditionally run actions based on the result of previous actions without managing a parameter. Code 200 is defined as a pass
• Action error handling is improved, currently returning HTTP-like codes. I may downgrade this to a boolean

Get Started

Using Karmen (Server):

1. See Docker Hub for releases
2. See an example config to start declaring your workflow
3. Run Karmen as part of your docker-compose.yml. see my example docker-compose.yml

Clients with examples:

• Python - example in karmen.py when executed as script
• Golang - example in main.go
• Or write your own! Karmen runs on gRPC. See existing implementations for reference

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• gRPC
• Golang
• Docker

Projects using Karmen

1. https://github.com/jrcichra/smartcar

Similar projects

1. https://netflix.github.io/conductor/

More docs to come!