Provisioning Kubernetes with SemaphoreUI and Kubespray: Automating Cluster Deployment

Semaphore UI is an open-source web-based interface for managing and automating Ansible tasks and CI/CD workflows. It allows DevOps engineers to visually organize playbooks, run commands, and monitor automation pipelines without complex terminal operations. This makes it a powerful tool for simplifying infrastructure deployment, especially when combined with Kubespray, an Ansible-based Kubernetes installer.

In this article, we’ll walk you through how to install and deploy Kubernetes using SemaphoreUI and Kubespray — from setting up your inventory and playbooks to running automated tasks via Semaphore pipelines. This approach not only reduces manual effort but also ensures repeatable, consistent, and production-ready Kubernetes deployments suitable for DevOps teams and cloud-native environments.

Topology

Lab Details

Kubernetes Version: v1.31.9

ETCD : Kubeadm

CNI: Calico

CRI: Containerd

OS: Ubuntu 22.04.5 LTS

Prerequisites

1. SemaphoreUI installed
2. All Kubernetes nodes can connect to each other via passwordless SSH

Preparation

1. Go to the terminal where SemaphoreUI is located, then clone kubespray. This lab uses Docker

docker exec -it  semaphore-semaphore-1 sh
git clone https://github.com/kubernetes-sigs/kubespray /tmp/kubespray
cd /tmp/kubespray

2. Then switch to the release-2.27 branch and install requirements.txt

/tmp/kubespray $ git checkout release-2.27
/tmp/kubespray $ pip install -U -r requirements.txt

Deploy Steps

1. The first step is to create a project in the Semaphore UI.
2. Then, copy the PrivateKey from k8s-master-01 as a jumphost for SSH to all nodes.

cat ~/.ssh/id_rsa
...
-----BEGIN OPENSSH PRIVATE KEY-----
...
...
...
-----END OPENSSH PRIVATE KEY-----

3. Then, create a repository.

Click Repository → NEW REPOSITORY-> SAVE

4. Create Inventory to include all hosts

Click Inventory → Ansible Inventory → NEW INVENTORY → Create

all:
  hosts:
    k8s-master-01:
      ansible_host: 10.10.61.21
      ip: 10.10.61.21
      access_ip: 10.10.61.21
      short_hostname: master-01
      node_taints:
        - "node-role.kubernetes.io/control-plane=:NoSchedule"
    k8s-master-02:
      ansible_host: 10.10.61.22
      ip: 10.10.61.22
      access_ip: 10.10.61.22
      short_hostname: master-02
      node_taints:
        - "node-role.kubernetes.io/control-plane=:NoSchedule"
    k8s-master-03:
      ansible_host: 10.10.61.23
      ip: 10.10.61.23
      access_ip: 10.10.61.23
      short_hostname: master-03
      node_taints:
        - "node-role.kubernetes.io/control-plane=:NoSchedule"
    k8s-worker-01:
      ansible_host: 10.10.61.25
      ip: 10.10.61.25
      access_ip: 10.10.61.25
      short_hostname: worker-01
      node_labels:
        node-role.kubernetes.io/worker: ""
        type: "app"
    k8s-worker-02:
      ansible_host: 10.10.61.26
      ip: 10.10.61.26
      access_ip: 10.10.61.26
      short_hostname: worker-02
      node_labels:
        node-role.kubernetes.io/worker: ""
        type: "app"
  children:
    kube_control_plane:
      hosts:
        k8s-master-01:
        k8s-master-02:
        k8s-master-03:
    kube_node:
      hosts:
        k8s-master-01:
        k8s-master-02:
        k8s-master-03:
        k8s-worker-01:
        k8s-worker-02:
    etcd:
      hosts:
        k8s-master-01:
        k8s-master-02:
        k8s-master-03:
    k8s_cluster:
      children:
        kube_control_plane:
        kube_node:
    calico_rr:
      hosts: {}

5. Then create Environment to define the cluster version, name clusters, etc.

Click Variable Groups → NEW GROUP → SAVE

6. Create a template: Task Templates → New Template → Ansible Playbook → Input Value → Create

Deploy Cluster

1. Select Task Templates and click Deploy Kubernetes → RUN

2. Wait for the deployment process to complete

Verification

1. Check the node status

2. Check kube-system pods

By combining SemaphoreUI and Kubespray, deploying Kubernetes becomes more efficient, consistent, and less error-prone. This automation-driven approach not only simplifies infrastructure management but also accelerates your CI/CD workflows — helping teams focus more on innovation rather than manual configuration.