Documentation updates for Backup/Restore and Uninstall/Reset

- Aligning the following documentation pages to cover both local and remote (k0sctl) procedures:
Upgrade, Backup/Restore, Uninstall/Reset
- Other minor documentation improvements

Signed-off-by: mviitanen <[email protected]>

docs/backup.md

@@ -1,12 +1,12 @@
 # Backup/Restore overview
 
-k0s has integrated support for backing up cluster state and configuration.
-The k0s backup utility is aiming to back up and restore k0s managed parts of the cluster.
+k0s has integrated support for backing up cluster state and configuration. The k0s backup utility is aiming to back up and restore k0s managed parts of the cluster.
 
 The backups created by `k0s backup` command have following pieces of your cluster:
 
 - certificates (the content of the `<data-dir>/pki` directory)
-- etcd snapshot, if the etcd storage is used
+- etcd snapshot, if the etcd datastore is used
+- Kine/SQLite snapshot, if the Kine/SQLite datastore is used
 - k0s.yaml
 - any custom defined manifests under the `<data-dir>/manifests`
 - any image bundles located under the `<data-dir>/images`
@@ -15,12 +15,14 @@ The backups created by `k0s backup` command have following pieces of your cluste
 Parts **NOT** covered by the backup utility:
 
 - PersistentVolumes of any running application
-- database content, in case if the `kine` is used as a storage driver
+- datastore, in case something else than etcd or Kine/SQLite is used
 - any configuration to the cluster introduced by manual changes (e.g. changes that weren't saved under the `<data-dir>/manifests`)
 
 Any of the backup/restore related operations MUST be performed on the controller node.
 
-## Backup
+## Backup/restore a k0s node locally
+
+### Backup (local)
 
 To create backup run the following command on the controller node:
 
@@ -33,7 +35,7 @@ The command provides backup archive using following naming convention: `k0s_back
 
 Because of the DateTime usage, it is guaranteed that none of the previously created archives would be overwritten.
 
-## Restore
+### Restore (local)
 
 To restore cluster state from the archive use the following command on the controller node:
 
@@ -42,6 +44,7 @@ k0s restore /tmp/k0s_backup_2021-04-26T19_51_57_000Z.tar.gz
 ```
 
 The command would fail if the data directory for the current controller has overlapping data with the backup archive content.
+
 The command would use the archived `k0s.yaml` as the cluster configuration description.
 
 In case if your cluster is HA, after restoring single controller node, join the rest of the controller nodes to the cluster.
@@ -50,3 +53,27 @@ E.g. steps for N nodes cluster would be:
 - Restore backup on fresh machine
 - Run controller there
 - Join N-1 new machines to the cluster the same way as for the first setup.
+
+## Backup/restore a k0s cluster using k0sctl
+
+With k0sctl you can perform cluster level backup and restore remotely with one command.
+
+### Backup (remote)
+
+To create backup run the following command:
+
+```shell
+k0sctl backup
+```
+
+k0sctl connects to the cluster nodes to create a backup. The backup file is stored in the current working directory.
+
+### Restore (remote)
+
+To restore cluster state from the archive use the following command:
+
+```shell
+k0sctl apply --restore-from /path/to/backup_file.tar.gz
+```
+
+The control plane load balancer address (externalAddress) needs to remain the same between backup and restore. This is caused by the fact that all worker node components connect to this address and cannot currently be re-configured.

docs/configuration-validation.md

@@ -9,6 +9,6 @@ k0s validate config --config path/to/config/file
 `validate config` sub-command can validate the following:
 
 1. YAML formatting
-2. [SANs addresses](#specapi-1)
-3. [Network providers](#specnetwork-1)
-4. [Worker profiles](#specworkerprofiles)
+2. [SAN addresses](/configuration/#specapi)
+3. [Network providers](/configuration/#specnetwork)
+4. [Worker profiles](/configuration/#specworkerprofiles)

docs/high-availability.md

@@ -8,11 +8,7 @@ You can create high availability for the control plane by distributing the contr
 
 You should plan to allocate the control plane nodes into different zones. This will avoid failures in case one zone fails.
 
-For etcd high availability it's recommended to configure 3 or 5 controller nodes.
-
-- With 3 nodes it's possible to lose one node and still have the quorum with 2 working nodes.
-- With 2 controller nodes, the quorum is lost if one node fails and there's only one working node left.
-- With 5 nodes it's possible to lose two nodes and still have the quorum with 3 working nodes.
+For etcd high availability it's recommended to configure 3 or 5 controller nodes. For more information, refer to the [etcd documentation](https://etcd.io/docs/latest/faq/#why-an-odd-number-of-cluster-members).
 
 ## Load Balancer
 

docs/reset.md

@@ -0,0 +1,63 @@
+# Uninstall/Reset
+
+k0s can be uninstalled locally with `k0s reset` command and remotely with `k0sctl reset` command. They remove all k0s-related files from the host.
+
+`reset` operates under the assumption that k0s is installed as a service on the host.
+
+## Uninstall a k0s node locally
+
+To prevent accidental triggering, `k0s reset` will not run if the k0s service is running, so you must first stop the service:
+
+1. Stop the service:
+
+    ```shell
+    sudo k0s stop
+    ```
+
+2. Invoke the `reset` command:
+
+    ```shell
+    $ sudo k0s reset
+    INFO[2021-06-29 13:08:39] * containers steps
+    INFO[2021-06-29 13:08:44] successfully removed k0s containers!
+    INFO[2021-06-29 13:08:44] no config file given, using defaults
+    INFO[2021-06-29 13:08:44] * remove k0s users step:
+    INFO[2021-06-29 13:08:44] no config file given, using defaults
+    INFO[2021-06-29 13:08:44] * uninstal service step
+    INFO[2021-06-29 13:08:44] Uninstalling the k0s service
+    INFO[2021-06-29 13:08:45] * remove directories step
+    INFO[2021-06-29 13:08:45] * CNI leftovers cleanup step
+    INFO k0s cleanup operations done. To ensure a full reset, a node reboot is recommended.
+    ```
+
+## Uninstall a k0s cluster using k0sctl
+
+k0sctl can be used to connect each node and remove all k0s-related files and processes from the hosts.
+
+1. Invoke `k0sctl reset` command:
+
+    ```shell
+    $ k0sctl reset --config k0sctl.yaml
+    k0sctl v0.9.0 Copyright 2021, k0sctl authors.
+
+    ? Going to reset all of the hosts, which will destroy all configuration and data, Are you sure? Yes
+    INFO ==> Running phase: Connect to hosts 
+    INFO [ssh] 13.53.43.63:22: connected              
+    INFO [ssh] 13.53.218.149:22: connected            
+    INFO ==> Running phase: Detect host operating systems 
+    INFO [ssh] 13.53.43.63:22: is running Ubuntu 20.04.2 LTS 
+    INFO [ssh] 13.53.218.149:22: is running Ubuntu 20.04.2 LTS 
+    INFO ==> Running phase: Prepare hosts    
+    INFO ==> Running phase: Gather k0s facts 
+    INFO [ssh] 13.53.43.63:22: found existing configuration 
+    INFO [ssh] 13.53.43.63:22: is running k0s controller version 1.21.2+k0s.0 
+    INFO [ssh] 13.53.218.149:22: is running k0s worker version 1.21.2+k0s.0 
+    INFO [ssh] 13.53.43.63:22: checking if worker  has joined 
+    INFO ==> Running phase: Reset hosts      
+    INFO [ssh] 13.53.43.63:22: stopping k0s           
+    INFO [ssh] 13.53.218.149:22: stopping k0s         
+    INFO [ssh] 13.53.218.149:22: running k0s reset    
+    INFO [ssh] 13.53.43.63:22: running k0s reset      
+    INFO ==> Running phase: Disconnect from hosts 
+    INFO ==> Finished in 8s                  
+    ```

mkdocs.yml

@@ -22,6 +22,7 @@ nav:
           - Airgap Install:               airgap-install.md
       - Upgrade:                          upgrade.md
       - Backup/Restore:                   backup.md
+      - Uninstall/Reset:                  reset.md
       - System Requirements:              system-requirements.md
   - Usage:
       - Configuration Options:            configuration.md
@@ -35,7 +36,6 @@ nav:
       - Control Plane High Availability:  high-availability.md
       - Shell Completion:                 shell-completion.md
       - User Management:                  user-management.md
-      - Uninstall the k0s Cluster:        k0s-reset.md
   - Extensions:
       - Manifest Deployer:                manifests.md
       - Helm Charts:                      helm-charts.md