70 lines
2 KiB
Markdown
70 lines
2 KiB
Markdown
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# Extending a cluster
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This document describes the method for extending an cluster with new worker
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nodes.
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## Assumptions
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It is assumed that you have already deployed a k3s cluster using this role,
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you have an appropriately configured inventory and playbook to create the
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cluster.
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Below, our example inventory and playbook are as follows:
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- inventory: `inventory.yml`
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- playbook: `cluster.yml`
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Currently your `inventory.yml` looks like this, it has two nodes defined,
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`kube-0` (control node) and `kube-1` (worker node).
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```yaml
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---
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k3s_cluster:
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hosts:
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kube-0:
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ansible_user: ansible
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ansible_host: 10.10.9.2
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ansible_python_interpreter: /usr/bin/python3
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kube-1:
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ansible_user: ansible
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ansible_host: 10.10.9.3
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ansible_python_interpreter: /usr/bin/python3
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```
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## Method
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We have our two nodes, one control, one worker. The goal is to extend this to
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add capacity by adding a new worker node, `kube-2`. To do this we will add the
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new node to our inventory.
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```yaml
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---
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k3s_cluster:
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hosts:
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kube-0:
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ansible_user: ansible
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ansible_host: 10.10.9.2
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ansible_python_interpreter: /usr/bin/python3
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kube-1:
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ansible_user: ansible
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ansible_host: 10.10.9.3
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ansible_python_interpreter: /usr/bin/python3
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kube-2:
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ansible_user: ansible
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ansible_host: 10.10.9.4
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ansible_python_interpreter: /usr/bin/python3
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```
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Once the new node has been added, you can re-run the automation to join it to
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the cluster. You should expect the majority of changes to the worker node being
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introduced to the cluster.
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```text
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PLAY RECAP *******************************************************************************************************
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kube-0 : ok=53 changed=1 unreachable=0 failed=0 skipped=30 rescued=0 ignored=0
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kube-1 : ok=40 changed=1 unreachable=0 failed=0 skipped=35 rescued=0 ignored=0
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kube-2 : ok=42 changed=10 unreachable=0 failed=0 skipped=35 rescued=0 ignored=0
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```
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