Fleet

Fleet by Rancher is a GitOps tool designed to manage large sets of Kubernetes clusters efficiently. In simple words, it can be used to take Kubernetes manifests from any Git repo & apply them to the cluster automatically. It can also manage Helm Charts, build Kustomize and even apply combinations of all three.

Architecture

The diagram below is a simplification of what actually happens behind the scenes, see the actual docs for a more detailed description.

flowchart TB
    gr[Git Repo]

    subgraph cluster[Kubernetes Cluster]
    subgraph fc[Fleet Controller]
    fgc(Fleet Git Cloner) -->|create bundle| fa
    fa(Fleet Apply)
    end
    subgraph tn[Tenant Namespace]
    grcrd([GitRepo CRD])
    bundle([Bundle]) --> hc
    subgraph hc[App Managed by GitOps]
    direction BT
    manif[Manifests]
    end
    end
    end

    fa --> bundle

    fgc ---> gr
    gr -.-> grcrd
    grcrd -.-> fc

Usage

To apply manifests from a repo, create a GitRepo CRD. You can do this either manually, or using the Rancher Continuous Delivery Tab.

apiVersion: fleet.cattle.io/v1alpha1
kind: GitRepo
metadata:
  labels:
    tenant: <tenant>
  name: <project>
  namespace: fleet-<tenant>
spec:
  branch: main
  paths:
    - /path/to/manifests
  repo: https://github.com/user/repo
  targetNamespace: <tenant>
  targets:
    - clusterName: tetra

For more detailed examples on how to use Fleets full functionality, please see the fleet-examples repo.