Upgrade Ambassador Edge Stack 2.4.X to Ambassador Edge Stack 2.5.1 (Helm)

Since Ambassador Edge Stack's configuration is entirely stored in Kubernetes resources, upgrading between minor versions is straightforward.

Migration is a two-step process:

1. Install new CRDs.

   Before installing Ambassador Edge Stack 2.5.1 itself, you need to update the CRDs in your cluster; Helm will not do this for you. This is mandatory during any upgrade of Ambassador Edge Stack.

   Ambassador Edge Stack 2.5.1 includes a Deployment in the `emissary-system` namespace called emissary-apiext. This is the APIserver extension that supports converting Ambassador Edge Stack CRDs between getambassador.io/v2and getambassador.io/v3alpha1. This Deployment needs to be running at all times.
   If the emissary-apiext Deployment's Pods all stop running, you will not be able to use getambassador.io/v3alpha1 CRDs until restarting the emissary-apiext Deployment.
   There is a known issue with the emissary-apiext service that impacts all Ambassador Edge Stack 2.x and 3.x users. Specifically, the TLS certificate used by apiext expires one year after creation and does not auto-renew. All users who are running Ambassador Edge Stack/Emissary-ingress 2.x or 3.x with the apiext service should proactively renew their certificate as soon as practical by running kubectl delete --all secrets --namespace=emissary-system to delete the existing certificate, and then restart the emissary-apiext deployment with kubectl rollout restart deploy/emissary-apiext -n emissary-system. This will create a new certificate with a one year expiration. We will issue a software patch to address this issue well before the one year expiration. Note that certificate renewal will not cause any downtime.

2. Install Ambassador Edge Stack 2.5.1.

   After installing the new CRDs, use Helm to install Ambassador Edge Stack 2.5.1. Start by making sure that your datawire Helm repo is set correctly:

   Then, update your Ambassador Edge Stack installation in the ambassador namespace. If necessary for your installation (e.g. if you were running with AMBASSADOR_SINGLE_NAMESPACE set), you can choose a different namespace.

   You must use the edge-stack Helm chart to install Ambassador Edge Stack 2.X. Do not use the ambassador Helm chart.