Add doc about migration

docs/README.md

@@ -7,3 +7,80 @@
   - [API Reference](api-reference.md)
 - [Migrate existing cluster to the operator](migration.md)
 - [Development](development.md)
+
+
+## Migrate from 0.1.0 to 0.2.0
+
+KAAP 0.2.0 is a major release that includes a new version of the CRDs. This means that you will need to migrate your existing CRDs to the new version. This process is described below.
+
+The CRDs specs are fully compatible, however it's required to change the existing custom resource definition version to v1beta1.
+
+This process ensures no downtime. One full cluster upgrade is required to complete the migration, and it's done automatically.
+
+
+1. Apply new CRD versions.
+
+This process will update the CRD adding a new version v1beta1.
+
+```
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/autorecoveries.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts 
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/bastions.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/bookkeepers.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/brokers.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/functionsworkers.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/proxies.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/zookeepers.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+kubectl apply -f https://github.com/datastax/kaap/releases/download/operator-0.2.0/pulsarclusters.kaap.oss.datastax.com-v1-migration.yml --server-side --force-conflicts
+```
+
+2. Copy the KAAP custom resources and move them to v1beta1
+
+```
+namespace=kaap # change this according to your kaap namespace
+name=pulsar # change this according to your pulsar cluster name
+kubectl get -n $namespace autorecoveries $name-autorecovery -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace bastions $name-bastion -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace bookkeepers $name-bookkeeper -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace brokers $name-broker -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace functionsworkers $name-functionsworker -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace proxies $name-proxy -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace zookeepers $name-zookeeper -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+kubectl get -n $namespace pulsarclusters $name -o yaml | sed 's/apiVersion: kaap.oss.datastax.com\/v1alpha1/apiVersion: kaap.oss.datastax.com\/v1beta1/' | kubectl apply -f -
+```
+
+Note: 
+`Warning: resource zookeepers/pulsar-zookeeper is missing the kubectl.kubernetes.io/last-applied-configuration annotation which is required by kubectl apply. kubectl apply should only be used on resources created declaratively by either kubectl create --save-config or kubectl apply. The missing annotation will be patched automatically.
+`
+can be ignored.
+
+
+Ensure the new resources exist:
+
+```
+kubectl get -n $namespace pulsarclusters.v1beta1.kaap.oss.datastax.com $name 
+```
+
+
+3. Now upgrade the chart to 0.2.0
+
+```
+helm repo update
+helm pull https://datastax.github.io/kaap
+helm upgrade kaap --version 0.2.0 -n $namespace kaap/kaap-stack -f <your-values.yaml>
+```
+
+
+4. Ensure everything is working fine.
+
+Now the KAAP pod is watching the v1beta1 resources.
+
+You should expect each component to be restarted.
+
+Run this command until it returns only one match:
+
+```
+kubectl get -n $namespace all -o yaml | grep kaap.oss.datastax.com/v1alpha1
+```
+
+The one match should be the ZooKeeper job.
+In case the broker has transactions enabled, you could see two matches.