Controller: Make Leader Election TTL configurable. (#11142)

* feature(leader_ttl): feature to customize ttl to leader be re-elected

* fix(review): docs

charts/ingress-nginx/README.md

@@ -297,6 +297,7 @@ As of version `1.26.0` of this chart, by simply not providing any clusterIP valu
 | controller.dnsConfig | object | `{}` | Optionally customize the pod dnsConfig. |
 | controller.dnsPolicy | string | `"ClusterFirst"` | Optionally change this to ClusterFirstWithHostNet in case you have 'hostNetwork: true'. By default, while using host network, name resolution uses the host's DNS. If you wish nginx-controller to keep resolving names inside the k8s network, use ClusterFirstWithHostNet. |
 | controller.electionID | string | `""` | Election ID to use for status update, by default it uses the controller name combined with a suffix of 'leader' |
+| controller.electionTTL | string | `""` | Duration a leader election is valid before it's getting re-elected, e.g. `15s`, `10m` or `1h`. (Default: 30s) |
 | controller.enableAnnotationValidations | bool | `false` |  |
 | controller.enableMimalloc | bool | `true` | Enable mimalloc as a drop-in replacement for malloc. # ref: https://github.com/microsoft/mimalloc # |
 | controller.enableTopologyAwareRouting | bool | `false` | This configuration enables Topology Aware Routing feature, used together with service annotation service.kubernetes.io/topology-mode="auto" Defaults to false |

charts/ingress-nginx/templates/_params.tpl

@@ -63,6 +63,9 @@
 {{- if .Values.controller.disableLeaderElection }}
 - --disable-leader-election=true
 {{- end }}
+{{- if .Values.controller.electionTTL }}
+- --election-ttl={{ .Values.controller.electionTTL }}
+{{- end }}
 {{- range $key, $value := .Values.controller.extraArgs }}
 {{- /* Accept keys without values or with false as value */}}
 {{- if eq ($value | quote | len) 2 }}

charts/ingress-nginx/values.yaml

@@ -85,6 +85,8 @@ controller:
   enableTopologyAwareRouting: false
   # -- This configuration disable Nginx Controller Leader Election
   disableLeaderElection: false
+  # -- Duration a leader election is valid before it's getting re-elected, e.g. `15s`, `10m` or `1h`. (Default: 30s)
+  electionTTL: ""
   # -- This configuration defines if Ingress Controller should allow users to set
   # their own *-snippet annotations, otherwise this is forbidden / dropped
   # when users add those annotations.