scale the machineset

Scale the machineset to the desired count before running kube-burner.

run.sh accepts the number of workers to scale for each avaialability
zone in region as env variable. Currently this patch is hard coded to
support us-west-2 region with 4 avaialaility zones.
For example, if user wants to scale US_WEST_2A to 143 nodes and
US_WEST_2B to 188 nodes, pass them to run.sh like below

US_WEST_2A=143 US_WEST_2B=188 WORKLOAD=node-desnity-cni ./run.sh

workloads/kube-burner-ocp-wrapper/run.sh

@@ -13,6 +13,10 @@ GC=${GC:-true}
 EXTRA_FLAGS=${EXTRA_FLAGS:-}
 UUID=${UUID:-$(uuidgen)}
 KUBE_DIR=${KUBE_DIR:-/tmp}
+US_WEST_2A=${US_WEST_2A:-}
+US_WEST_2B=${US_WEST_2B:-}
+US_WEST_2C=${US_WEST_2C:-}
+US_WEST_2D=${US_WEST_2D:-}
 
 download_binary(){
   KUBE_BURNER_URL=https://github.com/cloud-bulldozer/kube-burner/releases/download/v${KUBE_BURNER_VERSION}/kube-burner-V${KUBE_BURNER_VERSION}-linux-x86_64.tar.gz
@@ -116,6 +120,31 @@ fi
 # Capture the exit code of the run, but don't exit the script if it fails.
 set +e
 
+# scale machineset
+for machineset_name in $(oc get -n openshift-machine-api machineset --no-headers -o custom-columns=":.metadata.name" | grep -i worker); do
+  region=$(oc get -n openshift-machine-api machineset --no-headers -o custom-columns=":.spec.template.spec.providerSpec.value.placement.availabilityZone" $machineset_name)
+  # region will be of the form us-west-2a. We need to match it to user provided var i.e replae "-" with '_' and then convert it to upper case.
+  # For example us-west-2a will be converted to US_WEST_2A.
+  region_var=$(echo "$region" | tr '-' '_' | tr '[:lower:]' '[:upper:]')
+  # desired_replicas will be the value stored in US_WEST_2A (if povided by user)
+  desired_replicas=${!region_var}
+  if [[ "${desired_replicas}" != "" ]]; then
+	  echo "scale the ${machineset_name} to ${desired_replicas}"
+	  oc scale -n openshift-machine-api machineset "$machineset_name" --replicas="${desired_replicas}"
+	  # wait for 1 hour
+	  for ((i = 1; i <= 720; i++)); do
+		available_replicas=$(oc get -n openshift-machine-api -o template machineset "$machineset_name" --template={{.status.availableReplicas}})
+		if [ "$available_replicas" -eq "$desired_replicas" ]; then
+			echo "Desired number of replicas ($desired_replicas) reached."
+			break
+		fi
+		sleep 5
+	done
+
+  fi
+done
+
+
 # Label workers with ovnic. Metrics from only these workers are pulled.
 # node-desnity-cni on 500 nodes runs for 2 hours 15 minutes. Scraping metrics from 500 nodes for the duration of 2 hours 15 minutes is overkill.
 # So we scrape from only 10 worker nodes if the worker node count is more than 120.