fix: controller option to not watch configmap

.spelling

@@ -38,6 +38,8 @@ CloudSQL
 ClusterRoleBinding
 ClusterRoles
 Codespaces
+ConfigMap
+ConfigMaps
 Couler
 CronWorkflow
 CronWorkflows

docs/environment-variables.md

@@ -53,6 +53,7 @@ This document outlines environment variables that can be used to customize behav
 | `WF_DEL_PROPAGATION_POLICY`              | `string`            | `""`                                                                                        | The deletion propagation policy for workflows.                                                                                                                                                                                                                           |
 | `WORKFLOW_GC_PERIOD`                     | `time.Duration`     | `5m`                                                                                        | The periodicity for GC of workflows.                                                                                                                                                                                                                                     |
 | `SEMAPHORE_NOTIFY_DELAY`                 | `time.Duration`     | `1s`                                                                                        | Tuning Delay when notifying semaphore waiters about availability in the semaphore                                                                                                                                                                                        |
+| `WATCH_CONFIGMAPS` | `bool` | `true` | Whether to watch the Controller's ConfigMap and semaphore ConfigMaps for run-time changes. When disabled, the Controller will only read ConfigMaps once and will have to be manually restarted to pick up new changes. |
 
 CLI parameters of the Controller can be specified as environment variables with the `ARGO_` prefix.
 For example:

workflow/controller/controller.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 	gosync "sync"
@@ -308,7 +309,10 @@ func (wfc *WorkflowController) Run(ctx context.Context, wfWorkers, workflowTTLWo
 		log.Fatal(err)
 	}
 
-	go wfc.runConfigMapWatcher(ctx.Done())
+	if os.Getenv("WATCH_CONFIGMAPS") != "false" {
+		go wfc.runConfigMapWatcher(ctx.Done())
+	}
+
 	go wfc.wfInformer.Run(ctx.Done())
 	go wfc.wftmplInformer.Informer().Run(ctx.Done())
 	go wfc.podInformer.Run(ctx.Done())