operator: Fix IPAM default flag

Unless the user explicitly specifies the IPAM in use, fall back to the
default cilium-operator image and use the legacy host-scope IPAM to
ensure that during upgrade from a previous release that Cilium is not
automatically migrated to the new IPAM model; that should be an explicit
opt-in step that the user performs subsequently.

Signed-off-by: André Martins <andre@cilium.io>
Signed-off-by: Joe Stringer <joe@cilium.io>

Documentation/cmdref/cilium-operator-generic.md

@@ -36,7 +36,7 @@ cilium-operator-generic [flags]
       --identity-allocation-mode string         Method to use for identity allocation (default "kvstore")
       --identity-gc-interval duration           GC interval for security identities (default 15m0s)
       --identity-heartbeat-timeout duration     Timeout after which identity expires on lack of heartbeat (default 30m0s)
-      --ipam string                             Backend to use for IPAM (default "cluster-pool")
+      --ipam string                             Backend to use for IPAM (default "hostscope-legacy")
       --k8s-api-server string                   Kubernetes API server URL
       --k8s-client-burst int                    Burst value allowed for the K8s client
       --k8s-client-qps float32                  Queries per second limit for the K8s client

install/kubernetes/cilium/charts/operator/templates/deployment.yaml

@@ -37,8 +37,10 @@ spec:
         - cilium-operator-aws
 {{- else if .Values.global.azure.enabled }}
         - cilium-operator-azure
-{{- else }}
+{{- else if .Values.global.ipam.operator }}
         - cilium-operator-generic
+{{- else }}
+        - cilium-operator
 {{- end }}
         env:
         - name: K8S_NODE_NAME
@@ -114,8 +116,10 @@ spec:
         image: "{{ .Values.global.registry }}/{{ .Values.image }}-aws:{{ .Values.global.tag }}"
 {{- else if .Values.global.azure.enabled }}
         image: "{{ .Values.global.registry }}/{{ .Values.image }}-azure:{{ .Values.global.tag }}"
-{{- else }}
+{{- else if .Values.global.ipam.operator }}
         image: "{{ .Values.global.registry }}/{{ .Values.image }}-generic:{{ .Values.global.tag }}"
+{{- else }}
+        image: "{{ .Values.global.registry }}/{{ .Values.image }}:{{ .Values.global.tag }}"
 {{- end }}
 {{- end }}
         imagePullPolicy: {{ .Values.global.pullPolicy }}

operator/flags.go

@@ -124,7 +124,9 @@ func init() {
 	case "cilium-operator-azure":
 		defaultIPAM = ipamOption.IPAMAzure
 	case "cilium-operator-generic":
-		defaultIPAM = ipamOption.IPAMOperator
+		// Default to Legacy for upgrade paths; new users should
+		// explicitly override the IPAM flag.
+		defaultIPAM = ipamOption.IPAMHostScopeLegacy
 	}
 
 	flags.String(option.IPAM, defaultIPAM, "Backend to use for IPAM")