Add runbook for upgrade eks addons

runbooks/source/upgrade-eks-addons.html.md.erb

@@ -0,0 +1,69 @@
+---
+title: Upgrade EKS addons
+weight: 53
+last_reviewed_on: 2024-01-24
+review_in: 3 months
+---
+
+# Upgrade EKS addons
+
+We have 3 addons managed through cloud-platform-terraform-eks-add-ons [module](https://github.com/ministryofjustice/cloud-platform-terraform-eks-add-ons).
+
+Before every EKS major versions, check and upgrade if the addons versions don't match the EKS major version the cluster is currently on.
+
+After every EKS major versions, check  and upgrade if the addons don't match the EKS major version the cluster you just upgraded to.
+
+The following addons are managed through cloud-platform-terraform-eks-add-ons module.
+
+[managing-kube-proxy](https://docs.aws.amazon.com/eks/latest/userguide/managing-kube-proxy.html)
+
+[managing-coredns](https://docs.aws.amazon.com/eks/latest/userguide/managing-coredns.html)
+
+[managing-vpc-cni](https://docs.aws.amazon.com/eks/latest/userguide/managing-vpc-cni.html)
+
+## Listing available EKS upgrades
+
+### eksctl Install
+
+```
+brew install eksctl
+```
+
+Run the following command to get a list of supported addon version for the Kubernetes version.
+
+```
+eksctl utils describe-addon-versions --kubernetes-version [k8s-version] --name [addon name: kube-proxy/vpc-cni/coredns] | grep AddonVersion
+```
+
+## Preparing for upgrade
+
+Check the changelog for each of the addons and determine if there are any breaking changes.
+
+Create a thread in #cloud-platform notifying the team that upgrades are starting and the pipelines will be paused.
+
+## Starting the upgrade
+
+1. Bump the version number in cloud-platform-terraform-eks-add-ons
+2. Commit changes on a new branch and create a pull request
+3. Request review from someone on the team
+4. Merge pull request and create a new release through the Github UI
+5. Bump the version number of the cloud-platform-terraform-eks-add-ons in cloud-platform-infrastructure
+6. Commit changes on a new branch and create a pull request
+7. Request review form someone on the team
+8. Check the terraform plan in concourse and pause the following pipelines:
+  * bootstrap
+  * infrastructure-live
+  * infrastructure-manager
+  * infrastructure-live-2
+9. Create an output of the configuration of a pod before the upgrade. `kubectl -n kube-system get pod $addon -oyaml` there is also a helper [script](https://github.com/ministryofjustice/cloud-platform-infrastructure/blob/main/scripts/addons-upgrade.bash).
+10. Merge the pull request
+11. Unpause an infrastructure pipeline and wait for it to complete
+12. While running:
+  * Keep an eye on pods recycling `watch -n 1 "kubectl -n kube-system get pods"`
+  * Keep an eye on events `watch -n 1 "kubectl -n kube-system get events"`
+13. Run the reporting pipeline on the infrastructure environment
+14. If everythin is green repeat steps 11-14 on each environment.
+
+## Finish the upgrade
+
+Finish up communications and close the thread.

runbooks/source/upgrade-eks-cluster.html.md.erb

@@ -1,7 +1,7 @@
 ---
 title: Upgrade EKS cluster
 weight: 53
-last_reviewed_on: 2024-01-16
+last_reviewed_on: 2024-01-24
 review_in: 3 months
 ---
 
@@ -155,7 +155,7 @@ Before every EKS major versions, check and upgrade if the addons versions don't
 
 After every EKS major versions, check  and upgrade if the addons don't match the EKS major version the cluster you just upgraded to.
 
-The following addons are managed through cloud-platform-terraform-eks-add-ons [module](
+The following addons are managed through cloud-platform-terraform-eks-add-ons module.
 
 [managing-kube-proxy](https://docs.aws.amazon.com/eks/latest/userguide/managing-kube-proxy.html)