📖 docs(deployment): improve getting started docs

docs/topics/quickstart.md

@@ -1,5 +1,96 @@
-# Quickstart
+# Getting Started
+
+## Quickstart
 
 Currently, there is a [demo](https://github.com/SovereignCloudStack/cluster-stacks-demo) that can be used to see how the Cluster Stack approach can work. It uses the Docker Provider Integration for Cluster API.
 
-For production use, the Cluster Stack Operator can be used together with the [Cluster Stack Provider OpenStack](https://github.com/SovereignCloudStack/cluster-stack-provider-openstack) to manage Kubernetes clusters on OpenStack. You can see how it is used in the corresponding [Quickstart Documentation](../../cluster-stacks/providers/openstack/quickstart.md) of Cluster Stacks.
+## Installation
+
+### Prerequisites
+
+```
+- clusterctl
+- envsubst
+- kubectl
+- Helm (optional)
+```
+
+#### Cluster API
+
+We assume access to a Kubernetes cluster. To start
+[kind](https://kind.sigs.k8s.io/) can be used for that.
+This Kubernetes cluster must act as Cluster API management cluster.
+If not already done, to make your Kubernetes cluster a management cluster by
+installing the Cluster API objects, you can do
+
+```
+clusterctl init
+```
+
+### Configure Release Source
+
+The Cluster Stack Operator downloads Cluster Stack releases either from GitHub
+Releases or from an OCI registry.
+Depending on which method is preferred, environment variables must be set to
+give the Cluster Stack Operator access to the specific source.
+
+#### Using GitHub Releases
+
+> Be aware that GitHub enforces limitations on the number of API requests per
+> unit of time. To overcome this, it is recommended to configure a [personal
+> access token](https://github.com/settings/personal-access-tokens/new) for
+> authenticated calls. This will significantly increase the rate limit for GitHub
+> API requests. Fine grained PAT with `Public Repositories (read-only)` is
+> enough.
+
+Following variables tells the Cluster Stack Operator to look for releases in
+`https://github.com/SovereignCloudStack/cluster-stacks`
+
+```bash
+export GIT_PROVIDER_B64=Z2l0aHVi  # github
+export GIT_ORG_NAME_B64=U292ZXJlaWduQ2xvdWRTdGFjaw== # SovereignCloudStack
+export GIT_REPOSITORY_NAME_B64=Y2x1c3Rlci1zdGFja3M=  # cluster-stacks
+export GIT_ACCESS_TOKEN_B64=$(echo -n '<my-personal-access-token>' | base64 -w0)
+```
+
+#### Using OCI Registry
+
+Following variables tells the Cluster Stack Operator to look for releases in
+`https://registry.scs.community/kaas/cluster-stacks`
+
+```bash
+export OCI_REGISTRY_B64=cmVnaXN0cnkuc2NzLmNvbW11bml0eQ== # registry.scs.community
+export OCI_REPOSITORY_B64=cmVnaXN0cnkuc2NzLmNvbW11bml0eS9rYWFzL2NsdXN0ZXItc3RhY2tzCg== # registry.scs.community/kaas/cluster-stacks
+```
+
+If the registry is not public the Cluster Stack Operator please also provide
+`OCI_USERNAME_B64` and `OCI_PASSWORD_B64` or
+`OCI_ACCESS_TOKEN_B64`
+
+### Install Cluster Stack Operator
+
+#### Install by manifest
+
+```bash
+# Get the latest CSO release version and apply CSO manifests
+curl -sSL https://github.com/SovereignCloudStack/cluster-stack-operator/releases/latest/download/cso-infrastructure-components.yaml | envsubst | kubectl apply -f -
+```
+
+##### Enable OCI registry as source
+
+Since GitHub is set as default source for the Cluster Stack releases, this can be changed with a patch:
+
+```bash
+kubectl patch deployment -n cso-system cso-controller-manager --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/command", "value": ["/manager", "-source", "oci"]}]'
+```
+
+#### Install with Helm (experimental)
+
+There are simple Helm charts available which were created especially to make the switch between the sources easier.
+
+```bash
+helm upgrade -i cso -n cso-system \
+    --create-namespace oci://registry.scs.community/cluster-stacks/cso \
+    --set controllerManager.manager.source=oci \
+    --set clusterStackVariables.ociRepository=registry.scs.community/kaas/cluster-stacks
+```