chore: add upgrade docs for 1.33

docs/canonicalk8s/snap/howto/upgrades.md

@@ -60,7 +60,13 @@ To upgrade to a new minor version, the snap channel needs to be changed.
 snap info k8s
 ```
 
-2. **Change the snap channel:**
+2. **Check version specific instructions and possible manual steps**
+
+Please check [Upgrade notes] for any version-specific considerations or manual 
+steps before upgrading. 
+
+
+3. **Change the snap channel:**
 
 The {{product}} snap channel can be changed by using the `snap refresh`
 command.
@@ -69,7 +75,7 @@ command.
 snap refresh --channel=1.33/stable k8s
 ```
 
-3. **Verify the upgrade:**
+4. **Verify the upgrade:**
 
 Ensure that the upgrade was successful by checking the version of the snap
 and confirming that the cluster is ready:
@@ -104,3 +110,5 @@ snap refresh k8s --hold=24h
 [Version Skew Policy]: https://kubernetes.io/docs/setup/release/version-skew-policy/
 [backup guide]: ./backup-restore.md
 [snap documentation]: https://snapcraft.io/docs/managing-updates
+[Upgrade notes]: ../reference/upgrading
+

docs/canonicalk8s/snap/reference/releases.md

@@ -13,6 +13,16 @@ and backwards-incompatible changes.
 /snap/reference/versions/1.32
 ```
 
+## Upgrade notes
+
+Instructions on how to upgrade between versions on {{product}}
+
+```{toctree}
+:titlesonly:
+:maxdepth: 2
+/snap/reference/upgrading.md
+```
+
 
 ## Release policy and schedule
 

docs/canonicalk8s/snap/reference/upgrading.md

@@ -0,0 +1,55 @@
+# Upgrade notes
+
+## Upgrade 1.32 to 1.33
+
+If you are not using dual stack networking, you can simply run:
+
+```bash
+sudo snap refresh k8s --channel=1.33/stable
+```
+
+All components will be updated automatically.
+
+### Additional steps for dual-stack environments
+
+If your cluster is configured with dual stack networking (IPv4 and IPv6), 
+you’ll need to make a manual adjustment before refreshing. {{product}} 1.33 
+includes Cilium v1.17, which introduces a stricter requirement for dual stack: 
+each node must report both IPv4 and IPv6 addresses to the API server. 
+If this is not satisfied, the Cilium agent pods will fail to start. 
+For each node in the cluster:
+
+- Update the `--node-ip` flag in the kubelet configuration file 
+`/var/snap/k8s/common/args/kubelet` to include both the IPv4 and IPv6 addresses 
+(comma-separated) from the network interface that is used to connect the node 
+to the cluster network:
+
+```bash
+--node-ip=<IPv4>,<IPv6>
+```
+
+- Restart the `kubelet` service
+
+```bash
+sudo systemctl restart snap.k8s.kubelet.service
+```
+
+- Restart the Cilium DaemonSet:
+
+```bash
+sudo k8s kubectl rollout restart daemonset cilium -n kube-system
+```
+
+Now you can run the snap `refresh` command to perform the upgrade.
+
+### Verify the upgrade 
+
+Check the `k8s` snap version has been updated and the cluster is back in the 
+`Ready` state.
+
+```
+snap info k8s
+sudo k8s status --wait-ready
+```
+
+