94 lines
4.2 KiB
Markdown
94 lines
4.2 KiB
Markdown
# Stopping and Starting a cluster
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This document describes the Ansible method for restarting a k3s cluster
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deployed by this role.
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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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## Method
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### Start cluster
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You can start the cluster using either of the following commands:
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- Using the playbook: `ansible-playbook -i inventory.yml cluster.yml --become -e 'k3s_state=started'`
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- Using an ad-hoc command: `ansible -i inventory.yml -m service -a 'name=k3s state=started' --become all`
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Below is example output, remember that Ansible is idempotent so re-running a
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command may not necessarily change the state.
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**Playbook method output**:
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```text
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PLAY RECAP *******************************************************************************************************
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kube-0 : ok=6 changed=0 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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kube-1 : ok=6 changed=0 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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kube-2 : ok=6 changed=0 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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```
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### Stop cluster
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You can stop the cluster using either of the following commands:
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- Using the playbook: `ansible-playbook -i inventory.yml cluster.yml --become -e 'k3s_state=stopped'`
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- Using an ad-hoc command: `ansible -i inventory.yml -m service -a 'name=k3s state=stopped' --become all`
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Below is example output, remember that Ansible is idempotent so re-running a
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command may not necessarily change the state.
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**Playbook method output**:
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```text
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PLAY RECAP *******************************************************************************************************
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kube-0 : ok=6 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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kube-1 : ok=6 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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kube-2 : ok=6 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
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```
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### Restart cluster
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Just like the `service` module, you can also specify `restarted` as a state.
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This will do `stop` followed by `start`.
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- Using the playbook: `ansible-playbook -i inventory.yml cluster.yml --become -e 'k3s_state=restarted'`
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- Using an ad-hoc command: `ansible -i inventory.yml -m service -a 'name=k3s state=restarted' --become all`
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```text
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PLAY RECAP *******************************************************************************************************
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kube-0 : ok=7 changed=1 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0
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kube-1 : ok=7 changed=1 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0
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kube-2 : ok=7 changed=1 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0
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```
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## Tips
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You can limit the targets by adding the `-l` flag to your `ansible-playbook`
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command, or simply target your ad-hoc commands. For example, in a 3 node
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cluster (called `kube-0`, `kube-1` and `kube-2`) we can limit the restart to
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`kube-1` and `kube-2` with the following:
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- Using the playbook: `ansible-playbook -i inventory.yml cluster.yml --become -e 'k3s_state=restarted' -l "kube-1,kube-2"`
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- Using an ad-hoc command: `ansible -i inventory.yml -m service -a 'name=k3s state=restarted' --become "kube-1,kube-2"`
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```text
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PLAY RECAP ********************************************************************************************************
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kube-1 : ok=7 changed=2 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0
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kube-2 : ok=7 changed=2 unreachable=0 failed=0 skipped=3 rescued=0 ignored=0
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```
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## FAQ
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1. _Why might I use the `ansible-playbook` command over an ad-hoc command?_
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- The stop/start tasks will be aware of configuration. As the role
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develops, there might be some pre-tasks added to change how a cluster
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is stopped or started.
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