Commit 3030e32c authored by Julien DOCHE's avatar Julien DOCHE
Browse files

Support HA mode with embedded DB 

This enables initializing a cluster in HA mode with an embedded DB.
https://rancher.com/docs/k3s/latest/en/installation/ha-embedded/



When multiple masters are specified in the master group, k3s-ansible will add
the necessary flags during the initialization phase.
(i.e. --cluster-init and --server)

For the embedded HA mode to work the k3s version must be >= v1.19.1

Signed-off-by: default avatarJulien DOCHE <julien.doche@gmail.com>
parent f1163ffc

README.md

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@@ -26,6 +26,7 @@ Master and nodes must have passwordless SSH access 
First create a new directory based on the `sample` directory within the `inventory` directory:



```bash

pip install -r requirements.txt

cp -R inventory/sample inventory/my-cluster

```
@@ -43,6 +44,10 @@ master 
node

```



If multiple hosts are in the master group, the playbook will automatically setup k3s in HA mode with etcd.

https://rancher.com/docs/k3s/latest/en/installation/ha-embedded/

This requires at least k3s version 1.19.1



If needed, you can also edit `inventory/my-cluster/group_vars/all.yml` to match your environment.



Start provisioning of the cluster using the following command:

requirements.txt

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jmespath

roles/k3s/master/defaults/main.yml

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---

ansible_user: root

server_init_args: >-

  {% if groups['master'] | length > 1 %}

    {% if ansible_host == groups['master'][0] %}

      --cluster-init

    {% else %}

      --server https://{{ groups['master'][0] }}:6443

    {% endif %}

  {% endif %}

  {{ extra_server_args | default('') }}

roles/k3s/master/tasks/main.yml

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---

- name: Clean previous runs of k3s-init

  systemd:

    name: k3s-init

    state: stopped

  failed_when: false



- name: Clean previous runs of k3s-init

  command: systemctl reset-failed k3s-init

  failed_when: false

  changed_when: false

  args:

    warn: false  # The ansible systemd module does not support reset-failed



- name: Init cluster inside the transient k3s-init service

  command:

    cmd: "systemd-run -p RestartSec=2i \

                      -p Restart=on-failure \

                      -E K3S_TOKEN={{ hostvars[groups['master'][0]]['token'] }} \

                      --unit=k3s-init \

                      k3s server {{ server_init_args }}"

    creates: "{{ systemd_dir }}/k3s.service"

  args:

    warn: false  # The ansible systemd module does not support transient units



- name: Verification

  block:

    - name: Verify that all nodes actually joined

      command:

        cmd: k3s kubectl get --raw /api/v1/nodes/

        creates: "{{ systemd_dir }}/k3s.service"

      register: nodes

      until: nodes.rc == 0 and

        ((nodes.stdout | from_json)['items'] |

        json_query('[*].metadata.labels."node-role.kubernetes.io/master"') | count) == (groups['master'] | length)

      retries: 20

      delay: 10

      changed_when: false

  always:

    - name: Kill the temporary service used for initialization

      systemd:

        name: k3s-init

        state: stopped

      failed_when: false



- name: Copy K3s service file

  register: k3s_service

roles/reset/tasks/main.yml

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  with_items:

    - k3s

    - k3s-node

    - k3s-init



- name: pkill -9 -f "k3s/data/[^/]+/bin/containerd-shim-runc"

  register: pkill_containerd_shim_runc