update readme

Signed-off-by: Per Goncalves da Silva <[email protected]>

README.md

@@ -43,6 +43,7 @@ The ClusterCatalog resource supports file-based catalog ([FBC](https://olm.opera
 The following example uses the official [OperatorHub](https://operatorhub.io) catalog.
 
 ```bash
+# Create ClusterCatalog
 kubectl apply -f - <<EOF
 apiVersion: catalogd.operatorframework.io/v1alpha1
 kind: ClusterCatalog
@@ -57,10 +58,148 @@ spec:
 EOF
 ```
 
-Wait for the ClusterCatalog to be unpacked:
+```bash
+# Wait for the ClusterCatalog to be unpacked
+kubectl wait --for=condition=Unpacked=True clustercatalog/operatorhubio --timeout=60s
+```
+
+### Install Cluster Extension
+
+```bash
+# Apply the sample ClusterExtension. Manifest already includes
+# namespace and adequately privileged service account
+kubectl apply -f config/samples/olm_v1alpha1_clusterextension.yaml
+```
+
+#### Upgrade/Downgrade
+
+```bash
+# Update the required version
+kubectl patch clusterextension argocd --type='merge' -p '{"spec": {"version": "0.11.0"}}'
+```
+
+#### Uninstall
+
+```bash
+# Delete cluster extension and residing namespace
+kubectl delete clusterextension/argocd && kubectl delete namespace argocd
+```
+
+```bash
+# Delete cluster-scoped resources
+kubectl delete --ignore-not-found=true -f config/samples/olm_v1alpha1_clusterextension.yaml 
+```
+
+### Advanced Usage
+
+> [!WARNING]
+> The scripts referenced in this section are best-effort and may not always work as
+> intended. They are provided as a stopgap until we can offer production grade tooling
+> for tasks such as: searching the catalog, discovering supported bundles, and determining
+> the least-privilege set of permissions required by the installer service account to install
+> the content.
+
+#### Installation
+
+An extension needs a namespace in which to be installed and a service account with sufficient
+privileges to install the content. For instance:
+
+```bash
+# Create argocd namespace for the argocd-operator
+kubectl create ns argocd
+```
+
+```bash
+# Create installer service account
+kubectl create serviceaccount -n argocd-system argocd-installer
+```
+
+> [!WARNING]
+> We work around the absence of reliable tooling to determine the set of least privileges
+> for the installer service account to be able to install a given bundle by giving
+> the installer service account cluster admin privileges.
+> This is not an option for production clusters due to the security implications.
+> The OLM community is working hard to bridge this tooling gap.
+
+```bash
+# Give service account cluster admin privileges
+# This works with KIND - consult documentation for instructions on how
+# to grant admin privileges for your kubernetes distribution 
+kubectl create clusterrolebinding "argocd-operator-installer-cluster-admin" \
+    --clusterrole=cluster-admin \
+    --serviceaccount="argocd-system:argocd-operator-installer"
+```
+
+```bash
+# Apply ClusterExtension
+cat <<EOF
+apiVersion: olm.operatorframework.io/v1alpha1
+kind: ClusterExtension
+metadata:
+  name: argocd
+spec:
+  installNamespace: argocd-system
+  packageName: argocd-operator
+  version: 0.6.0
+  serviceAccount:
+    name: argocd-operator-installer
+EOF | kubectl apply -f -
+```
+
+```bash
+# Wait for installation to finish successfully
+kubectl wait --for=condition=Success=True clusterextension/argocd --timeout=60s
+```
+
+#### Finding Content
+
+The catalog content can be downloaded locally as a json file and queried using tools like [jq](The catalog content can be downloaded locally as a json file and queried using tools like [jq](The catalog content can be downloaded locally as a json file and queried using tools like [jq](https://jqlang.github.io/jq/).
+The _catalogd-catalogserver_ service in the _olmv1-system_ namespace provides an endpoint from which to
+download the catalog. This endpoint can be found in the status (.status.contentURL). 
+
+The [download-catalog.sh](hack/tools/catalogs/download-catalog.sh) script automates this process:
+
+```bash
+# Download the catalog provided by the unpacked ClusterCatalog called operatorhuio
+# The catalog will be downloaded to operatorhubio-catalog.json
+./hack/tools/catalogs/download-catalog.sh operatorhubio
+```
+
+OLM v1 currently supports the installation of bundles that:
+- support the 'AllNamespaces' install mode
+- do not have any package or gvk dependencies
+- do not have webhooks
+
+The [list-compatible-bundles.sh](hack/tools/catalogs/list-compatible-bundles.sh) script attempts
+to filter out unsupported bundles:
+
+```bash
+# Returns a JSON array of {packageName: "", versions: ["", ...]} objects
+# This array can be further queried with jq
+./hack/tools/catalogs/list-compatible-bundles.sh < operatorhubio-catalog.json
+# The -r option also allows you to define a regular expression for the package name
+# for futher filtering
+./hack/tools/catalogs/list-compatible-bundles.sh -r 'argocd' < operatorhubio-catalog.json
+```
+
+#### Determining Service Account Privileges
+
+The installer service account needs sufficient privileges to create the bundle's resources,
+as well as to assign RBAC to those resources. This information can be derived from the 
+bundle's ClusterServiceVersion manifest.
+
+The [install-bundle.sh](hack/tools/catalogs/install-bundle.sh) script generates all required
+manifests for a bundle installation (including Namespace, and ClusterExtension resources), but can also
+be used to determine the RBAC for the installer service account:
 
 ```bash
-kubectl wait --for=condition=Unpacked=True clustercatalog/operatorhubio --timeout=300s
+# Get RBAC for a ClusterExtension called 'argocd'
+# using package 'argocd-operator' at version '0.6.0'
+# in namespace 'argocd-system'
+RBAC_ONLY=1 ./hack/tools/catalogs/install-bundle.sh argocd argocd-operator 0.6.0 argocd-system < operatorhubio-catalog.json
+# Or, let the script do all the heavy lifting (creation of Namespace, and ClusterExtension, as well as
+# the ServiceAccount and all required RBAC
+./hack/tools/catalogs/install-bundle.sh argocd argocd-operator 0.6.0 argocd-system < operatorhubio-catalog.json | kubectl apply -f -
 ```
 
 ## License