create connect_aks as common function. (#3)

Author: galiacheng

weblogic-azure-aks/src/main/arm/scripts/inline-scripts/enableHpa.sh

@@ -0,0 +1,68 @@
+# Copyright (c) 2024, Oracle Corporation and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl.
+
+function get_cluster_uid(){
+  local clusterUid=$(kubectl get clusters -n ${WLS_NAMESPACE} -o=jsonpath='{.items[].metadata.name}')
+  utility_validate_status "Obtain cluster UID."
+  export WLS_CLUSTER_UID=${clusterUid}
+}
+
+function scaling_basedon_cpu(){
+    kubectl autoscale cluster ${WLS_CLUSTER_UID} \
+        --cpu-percent=${UTILIZATION_PERCENTAGE} \
+        --min=1 \
+        --max=${WLS_CLUSTER_SIZE} \
+        -n ${WLS_NAMESPACE}
+    utility_validate_status "Enable HPA based on CPU utilization."
+}
+
+function scaling_basedon_memory(){
+  cat <<EOF >scaler-memory.yaml
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: ${WLS_CLUSTER_UID}
+  namespace: ${WLS_NAMESPACE}
+spec:
+  scaleTargetRef:
+    apiVersion: weblogic.oracle/v1
+    kind: Cluster
+    name: ${WLS_CLUSTER_UID}
+  minReplicas: 1
+  maxReplicas: ${WLS_CLUSTER_SIZE}
+  metrics:
+  - type: Resource
+    resource:
+      name: memory
+      target:
+        averageUtilization: ${UTILIZATION_PERCENTAGE}
+        type: Utilization
+EOF
+
+  kubectl apply -f scaler-memory.yaml
+  utility_validate_status "Enable HPA based on memory utilization."
+}
+
+function check_kubernetes_metrics_server(){
+  # $?=1 if there is no running kms pod.
+  kubectl get pod -l k8s-app=metrics-server -n kube-system | grep "Running"
+  # exit if $?=1
+  utility_validate_status "There should be at least one pod of kubernetes metrics server running."
+}
+
+# Main script
+set -Eo pipefail
+
+install_kubectl
+
+connect_aks $AKS_CLUSTER_NAME $AKS_CLUSTER_RG_NAME
+
+get_cluster_uid
+
+check_kubernetes_metrics_server
+
+if [ "$HPA_SCALE_TYPE" == "cpu" ]; then
+  scaling_basedon_cpu
+elif [ "$HPA_SCALE_TYPE" == "memory" ]; then
+  scaling_basedon_memory
+fi