📖[Docs] How-to: Channel-Based Automatic Updates (#1220)

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

Author: perdasilva

docs/drafts/how-to-channel-based-upgrades.md

@@ -0,0 +1,45 @@
+## How-to: Channel-Based Automatic Upgrades
+
+A "channel" is a package author defined stream of updates for an extension. A set of channels can be set in the Catalog source to restrict automatic updates to the set of versions defined in those channels.
+
+Example:
+
+```yaml
+apiVersion: olm.operatorframework.io/v1alpha1
+kind: ClusterExtension
+metadata:
+  name: argocd
+spec:
+  source:
+    sourceType: Catalog
+    catalog:
+      packageName: argocd-operator
+      # Automatically upgrade to the latest version found in the preview and dev-preview channels
+      channels: [dev-preview, preview]
+  install:
+    namespace: argocd
+    serviceAccount:
+      name: argocd-installer
+```
+
+Note that the `version` field also accepts a version range to further restrict the set of possible upgradable operator versions.
+
+Example:
+
+```yaml
+apiVersion: olm.operatorframework.io/v1alpha1
+kind: ClusterExtension
+metadata:
+  name: argocd
+spec:
+  source:
+    sourceType: Catalog
+    catalog:
+      packageName: argocd-operator
+      channels: [stable] # Automatically upgrade to the latest version found in ‘stable’
+      version: “!1.3.2” # Don’t allow version 1.3.2
+  install:
+    namespace: argocd
+    serviceAccount:
+      name: argocd-installer
+```