initial commit

ansible/ansible.cfg

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+[defaults]
+inventory          = inventory.ini
+remote_user        = cloud-user
+private_key_file   = ../terraform/k8s_terraform
+host_key_checking  = False
+stdout_callback    = default
+result_format      = yaml
+interpreter_python = /usr/bin/python3.12
+deprecation_warnings = False
+
+[privilege_escalation]
+become      = True
+become_method = sudo

ansible/inventory.ini

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+[masters]
+master01 ansible_host=192.168.1.31
+
+[workers]
+worker01 ansible_host=192.168.1.35
+worker02 ansible_host=192.168.1.36
+worker03 ansible_host=192.168.1.37
+
+[k8s:children]
+masters
+workers

ansible/playbooks/01-common.yml

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+---
+- name: Common OS prerequisites for all k8s nodes
+  hosts: k8s
+  become: true
+
+  tasks:
+    - name: Disable swap now
+      command: swapoff -a
+      when: ansible_facts['swaptotal_mb'] > 0
+
+    - name: Remove swap from /etc/fstab
+      replace:
+        path: /etc/fstab
+        regexp: '^([^#].*\s+swap\s+.*)$'
+        replace: '# \1'
+
+    - name: Load kernel modules at boot
+      copy:
+        dest: /etc/modules-load.d/k8s.conf
+        content: |
+          overlay
+          br_netfilter
+
+    - name: Load kernel modules now
+      modprobe:
+        name: "{{ item }}"
+      loop:
+        - overlay
+        - br_netfilter
+
+    - name: Set sysctl for k8s networking
+      copy:
+        dest: /etc/sysctl.d/k8s.conf
+        content: |
+          net.bridge.bridge-nf-call-iptables  = 1
+          net.bridge.bridge-nf-call-ip6tables = 1
+          net.ipv4.ip_forward                 = 1
+
+    - name: Apply sysctl
+      command: sysctl --system

ansible/playbooks/02-hosts.yml

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+---
+- name: Configure /etc/hosts for all nodes
+  hosts: k8s
+  become: true
+
+  tasks:
+    - name: Add cluster nodes to /etc/hosts
+      blockinfile:
+        path: /etc/hosts
+        marker: "# {mark} k8s cluster nodes"
+        block: |
+          192.168.1.31  master01
+          192.168.1.35  worker01
+          192.168.1.36  worker02
+          192.168.1.37  worker03

ansible/playbooks/03-containerd.yml

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+---
+- name: Install and configure containerd
+  hosts: k8s
+  become: true
+
+  tasks:
+    - name: Add Docker CE repo (provides containerd.io)
+      get_url:
+        url: https://download.docker.com/linux/centos/docker-ce.repo
+        dest: /etc/yum.repos.d/docker-ce.repo
+
+    - name: Install containerd
+      dnf:
+        name: containerd.io
+        state: present
+
+    - name: Create containerd config directory
+      file:
+        path: /etc/containerd
+        state: directory
+
+    - name: Generate default containerd config (overwrites Docker CE default which disables CRI)
+      shell: containerd config default > /etc/containerd/config.toml
+
+    - name: Enable SystemdCgroup in containerd config
+      replace:
+        path: /etc/containerd/config.toml
+        regexp: 'SystemdCgroup = false'
+        replace: 'SystemdCgroup = true'
+
+    - name: Enable and start containerd
+      systemd:
+        name: containerd
+        enabled: true
+        state: restarted

ansible/playbooks/04-kube-tools.yml

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+---
+- name: Install kubeadm, kubelet, kubectl
+  hosts: k8s
+  become: true
+
+  vars:
+    kube_version: "1.32"
+
+  tasks:
+    - name: Add Kubernetes repo
+      copy:
+        dest: /etc/yum.repos.d/kubernetes.repo
+        content: |
+          [kubernetes]
+          name=Kubernetes
+          baseurl=https://pkgs.k8s.io/core:/stable:/v{{ kube_version }}/rpm/
+          enabled=1
+          gpgcheck=1
+          gpgkey=https://pkgs.k8s.io/core:/stable:/v{{ kube_version }}/rpm/repodata/repomd.xml.key
+          exclude=kubelet kubeadm kubectl cri-tools kubernetes-cni
+
+    - name: Install kubeadm, kubelet, kubectl
+      dnf:
+        name:
+          - kubelet
+          - kubeadm
+          - kubectl
+        state: present
+        disable_excludes: kubernetes
+
+    - name: Enable kubelet
+      systemd:
+        name: kubelet
+        enabled: true
+        state: started

ansible/playbooks/05-master-init.yml

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+---
+- name: Initialize Kubernetes master
+  hosts: masters
+  become: true
+
+  vars:
+    pod_network_cidr: "10.244.0.0/16"   # Flannel default
+
+  tasks:
+    - name: Check if cluster already initialized
+      stat:
+        path: /etc/kubernetes/admin.conf
+      register: kubeadm_init_done
+
+    - name: Run kubeadm init
+      command: >
+        kubeadm init
+        --apiserver-advertise-address={{ ansible_host }}
+        --pod-network-cidr={{ pod_network_cidr }}
+      when: not kubeadm_init_done.stat.exists
+      register: kubeadm_output
+
+    - name: Create .kube dir for cloud-user
+      file:
+        path: /home/cloud-user/.kube
+        state: directory
+        mode: "0700"
+        owner: cloud-user
+        group: cloud-user
+
+    - name: Copy admin.conf to cloud-user kubeconfig
+      copy:
+        src: /etc/kubernetes/admin.conf
+        dest: /home/cloud-user/.kube/config
+        remote_src: true
+        owner: cloud-user
+        group: cloud-user
+        mode: "0600"
+
+    - name: Create .kube dir for root (enables sudo kubectl)
+      file:
+        path: /root/.kube
+        state: directory
+        mode: "0700"
+
+    - name: Copy admin.conf to root kubeconfig
+      copy:
+        src: /etc/kubernetes/admin.conf
+        dest: /root/.kube/config
+        remote_src: true
+        mode: "0600"
+
+    - name: Install Flannel CNI
+      command: kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml
+      environment:
+        KUBECONFIG: /etc/kubernetes/admin.conf
+
+    - name: Get join command
+      command: kubeadm token create --print-join-command
+      register: join_command
+
+    - name: Save join command to local file
+      local_action:
+        module: copy
+        content: "{{ join_command.stdout }}"
+        dest: /tmp/k8s_join_command.sh
+        mode: "0600"

ansible/playbooks/06-worker-join.yml

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+---
+- name: Join workers to Kubernetes cluster
+  hosts: workers
+  become: true
+
+  tasks:
+    - name: Check if already joined
+      stat:
+        path: /etc/kubernetes/kubelet.conf
+      register: kubelet_conf
+
+    - name: Read join command from local file
+      local_action:
+        module: slurp
+        src: /tmp/k8s_join_command.sh
+      register: join_command_b64
+      when: not kubelet_conf.stat.exists
+
+    - name: Join cluster
+      command: "{{ join_command_b64.content | b64decode | trim }}"
+      when: not kubelet_conf.stat.exists