[OCCM] add environment variable for timeout (kubernetes#2235)

Author: jichenjc

docs/openstack-cloud-controller-manager/using-openstack-cloud-controller-manager.md

@@ -289,6 +289,8 @@ NOTE:
 
 * When using `ovn` provider service has limited scope - `create_monitor` is not supported and only supported `lb-method` is `SOURCE_IP`.
 
+* environment variable `OCCM_WAIT_LB_ACTIVE_STEPS` is used to provide steps of waiting loadbalancer to be ready. Current default wait steps is 23 and setup the environment variable overrides default value. Refer to [Backoff.Steps](https://pkg.go.dev/k8s.io/apimachinery/pkg/util/wait#Backoff) for further information.
+
 ### Metadata
 
 * `search-order`

pkg/util/openstack/loadbalancer.go

@@ -18,6 +18,8 @@ package openstack
 
 import (
 	"fmt"
+	"os"
+	"strconv"
 	"time"
 
 	"github.com/gophercloud/gophercloud"
@@ -159,13 +161,24 @@ func IsOctaviaFeatureSupported(client *gophercloud.ServiceClient, feature int, l
 	return false
 }
 
+func getTimeoutSteps(name string, steps int) int {
+	if v := os.Getenv(name); v != "" {
+		s, err := strconv.Atoi(v)
+		if err == nil && s >= 0 {
+			return s
+		}
+	}
+	return steps
+}
+
 // WaitActiveAndGetLoadBalancer wait for LB active then return the LB object for further usage
 func WaitActiveAndGetLoadBalancer(client *gophercloud.ServiceClient, loadbalancerID string) (*loadbalancers.LoadBalancer, error) {
 	klog.InfoS("Waiting for load balancer ACTIVE", "lbID", loadbalancerID)
+	steps := getTimeoutSteps("OCCM_WAIT_LB_ACTIVE_STEPS", waitLoadbalancerActiveSteps)
 	backoff := wait.Backoff{
 		Duration: waitLoadbalancerInitDelay,
 		Factor:   waitLoadbalancerFactor,
-		Steps:    waitLoadbalancerActiveSteps,
+		Steps:    steps,
 	}
 
 	var loadbalancer *loadbalancers.LoadBalancer