PEW PEW PEW PEW PEW!!!
LaserCats is a prototype for a CQRS based configuration and infrastructure management system. It is based on a simple concept, all infrastructure is a form of state. State can be stored on disk, serialized as a log of commands and events, queried, modified and stored on disk again. The state is a document that describes the infrastructure and said document can be used to recreate the infrastructure. CQRS makes that possible.
Lasercats is in the very early stages. I am currently prototyping the ability to issue high level commands, interpret them into instructions, and then rewrite history to derive an equivalent log of commands. Along the way, I will be developing some rudimentary state management and storage, a rudimentary query engine and a demonstration of multiple interpreters.
Most development will be focused on getting the types right and proceed slowly.
Infrastructure operators prefer having direct commands to operate their infrastructure. Direct control is crucial to enable operators to change the parameters of the systems they run quickly in response to changing conditions, especially where automation has failed. Likewise, direct feedback is neccessary for both skilled operators to continue maintaining control and operators learning how to operate the system. Direct commands in CQRS facilitate this.
Automation is one step removed from control but also crucial to manage large scale systems and infrastructure. It enables operators to achieve more with less work by leveraging what computers can do. The current trend is to describe infrastructure as declarative code and data structures. Folding commands, events and declarative documents enables operators to combine the flexibility of individual commands with the need for broad automation.
Systems and machines normally process and interpret commands through the lens of their machinery. Allowing alternative interpretation of commands and events enables operators to simulate changes to infrastructure, apply changes to test environments first and even troubleshoot problems. A command and event log enables operators to develop and use simpler interpreters.
All infrastructure is a form of state, whether ingrained in software, such as the state of EC2 instances, switch port configuration, or files on disk, or at a hardware level, such as the configuration of a 48U rack. Commands change the state, which creates events describing the change in state. This state can be regenerated from events, with limitations, or be used to generate instructions to recreate infrastructure.
Commands are rarely issued blindly. Queries close the loop between commands and feedback, enabling operators to issue commands dependent on the current state of the system. Declarative infrastructure can be built as a Query-Command pair.
Copyright 2018 Yaakov M Nemoy
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
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