Add a deployment management mode configuration similar to allocation management mode

[fordN]

Background

Indexers may have other systems/tools for managing deployments, so we'd like to provide the option for turning off deployment management in the indexer-agent.

Goal

Add feature to support different deployment management modes, so indexers can turn off deployment management.
Ultimately we can work towards a setup very similar to the allocation management modes: auto, manual and oversight that will give indexers queue management control of deployment changes. However, in the beginning we can keep it simple and just support auto and manual modes.

Tasks

• Add a startup parameter, deploymentManagement, with supported options: auto and manual
• Add a conditional checking this parameter that will skip reconciling deployments if mode = manual