Canary rollout proposal

README.md

+# Canary
+
+
+## Initial state
+
+In our initial situation, we have a single `IstioOperator` object pegged on version 1.1.0 as follows
+
+```bash
+❯ helm template chart                                               
+---
+# Source: chart/templates/main.yaml
+apiVersion: install.istio.io/v1alpha1
+kind: IstioOperator
+metadata:
+  annotations:
+    meta.helm.sh/release-name: istio-system-istio
+    meta.helm.sh/release-namespace: istio-system
+  labels:
+    app.kubernetes.io/managed-by: Helm
+    helm.toolkit.fluxcd.io/name: istio
+    helm.toolkit.fluxcd.io/namespace: bigbang
+  name: istiocontrolplane
+  namespace: istio-system
+spec:
+  revision: 1.1.0
+
+```
+
+
+## Canary Deployment
+
+As part of our testing of upgrades, we want to deploy a new (additional) version of the `IstioOperator` to test version 1.2.0 as follows:
+
+```bash
+---
+# Source: chart/templates/canary.yaml
+apiVersion: install.istio.io/v1alpha1
+kind: IstioOperator
+metadata:
+  annotations:
+    meta.helm.sh/release-name: istio-system-istio
+    meta.helm.sh/release-namespace: istio-system
+  labels:
+    app.kubernetes.io/managed-by: Helm
+    helm.toolkit.fluxcd.io/name: istio
+    helm.toolkit.fluxcd.io/namespace: bigbang
+  name: istiocontrolplane-canary
+  namespace: istio-system
+spec:
+  revision: 1.2
+---
+# Source: chart/templates/main.yaml
+apiVersion: install.istio.io/v1alpha1
+kind: IstioOperator
+metadata:
+  annotations:
+    meta.helm.sh/release-name: istio-system-istio
+    meta.helm.sh/release-namespace: istio-system
+  labels:
+    app.kubernetes.io/managed-by: Helm
+    helm.toolkit.fluxcd.io/name: istio
+    helm.toolkit.fluxcd.io/namespace: bigbang
+  name: istiocontrolplane
+  namespace: istio-system
+spec:
+  revision: 1.1.0
+```
+
+## Remove Canary
+
+Once the canary is accepted, we can deploy the new version of the software:
+
+```bash
+❯ helm template chart --set tag=1.2                                 
+---
+# Source: chart/templates/main.yaml
+apiVersion: install.istio.io/v1alpha1
+kind: IstioOperator
+metadata:
+  annotations:
+    meta.helm.sh/release-name: istio-system-istio
+    meta.helm.sh/release-namespace: istio-system
+  labels:
+    app.kubernetes.io/managed-by: Helm
+    helm.toolkit.fluxcd.io/name: istio
+    helm.toolkit.fluxcd.io/namespace: bigbang
+  name: istiocontrolplane
+  namespace: istio-system
+spec:
+  revision: 1.2
+```
+
+which updates the initial IstioOperator object with the new version.