Concepts

Concepts around ksctl core

1: Cloud Controller
2: Core Manager
3: Distribution Controller

This section will help you to learn about the underlying system of Ksctl. It will help you to obtain a deeper understanding of how Ksctl works.

Sequence diagrams for 2 major operations

Create Cloud-Managed Clusters

sequenceDiagram
    participant cm as Manager Cluster Managed
    participant cc as Cloud Controller
    participant kc as Ksctl Kubernetes Controller
    cm->>cc: transfers specs from user or machine
    cc->>cc: to create the cloud infra (network, subnet, firewall, cluster)
    cc->>cm: 'kubeconfig' and other cluster access to the state
    cm->>kc: shares 'kubeconfig'
    kc->>kc: installs kubectl agent, stateimporter and controllers
    kc->>cm: status of creation

Create Self-Managed HA clusters

sequenceDiagram
    participant csm as Manager Cluster Self-Managed
    participant cc as Cloud Controller
    participant bc as Bootstrap Controller
    participant kc as Ksctl Kubernetes Controller
    csm->>cc: transfers specs from user or machine
    cc->>cc: to create the cloud infra (network, subnet, firewall, vms)
    cc->>csm: return state to be used by BootstrapController
    csm->>bc: transfers infra state like ssh key, pub IPs, etc
    bc->>bc: bootstrap the infra by either (k3s or kubeadm)
    bc->>csm: 'kubeconfig' and other cluster access to the state
    csm->>kc: shares 'kubeconfig'
    kc->>kc: installs kubectl agent, stateimporter and controllers
    kc->>csm: status of creation

1 - Cloud Controller

The Component of Ksctl responsible for creating and managing clusters for different Cloud platforms.

It is responsible for controlling the sequence of tasks for every cloud provider to be executed

2 - Core Manager

The Component of Ksctl responsible for managing Cloud controller and Distribution controller. It has multiple types of managers

It is responsible for managing client requests and calls the corresponding controller

Types

ManagerClusterKsctl

Role: Perform ksctl getCluster, switchCluster

ManagerClusterKubernetes

Role: Perform ksctl addApplicationAndCrds Currently to be used by machine to machine not by ksctl cli

ManagerClusterManaged

Role: Perform ksctl createCluster, deleteCluster

ManagerClusterSelfManaged

Role: Perform ksctl createCluster, deleteCluster, addWorkerNodes, delWorkerNodes

3 - Distribution Controller

The Component of Ksctl responsible for selecting the type of Bootstrap solution (Kubeadm or K3s).

It is responsible for controlling the execution sequence for configuring Cloud Resources wrt to the Kubernetes distribution choosen