This PR adds a new provider for Flux CD, similar to the existing ArgoCD provider. Flux CD is a GitOps tool for Kubernetes that provides continuous delivery through automated deployment, monitoring, and management of applications.

Features Implemented

Topology Integration

• Pull topology data from Flux CD resources (GitRepositories, HelmRepositories, Kustomizations, HelmReleases)
• Create a graph of services with proper dependencies
• Categorize resources as “source” or “deployment”

Alert Integration

• Pull alerts from Kubernetes events related to Flux CD controllers
• Pull alerts from resource status conditions (non-ready resources)
• Determine alert severity based on event reason
• Provide detailed alert information

Authentication Options

• Support for kubeconfig file content
• Support for API server URL and token
• Support for in-cluster configuration
• Support for default kubeconfig file

Provider Metadata

• Get Flux CD version
• Get installed controllers
• Get resource counts

Implementation Details

• Created a new provider class FluxcdProvider that extends BaseTopologyProvider
• Implemented authentication with Kubernetes API
• Implemented methods to get Flux CD resources (GitRepositories, Kustomizations, HelmReleases)
• Implemented the pull_topology method to create a topology map
• Implemented the get_alerts method to pull alerts from Flux CD
• Added comprehensive error handling and logging
• Added unit tests for all functionality
• Added documentation

Documentation

• Added a README.md file with comprehensive documentation
• Added a documentation file for the Keep documentation site

Testing

• Added unit tests for all functionality
• Tested with a local Kubernetes cluster running Flux CD

/fixes #4632 /claim #4632