AMI release to get Cluster DNS IP from SCIDR for Self Managed Nodegro…

…ups (#525)

Co-authored-by: Laxmi Soumya Josyula <ljosyula@amazon.com>

files/bootstrap.sh

@@ -100,6 +100,7 @@ set -u
 USE_MAX_PODS="${USE_MAX_PODS:-true}"
 B64_CLUSTER_CA="${B64_CLUSTER_CA:-}"
 APISERVER_ENDPOINT="${APISERVER_ENDPOINT:-}"
+DNS_CLUSTER_IP="${DNS_CLUSTER_IP:-}"
 KUBELET_EXTRA_ARGS="${KUBELET_EXTRA_ARGS:-}"
 ENABLE_DOCKER_BRIDGE="${ENABLE_DOCKER_BRIDGE:-false}"
 API_RETRY_ATTEMPTS="${API_RETRY_ATTEMPTS:-3}"
@@ -218,7 +219,7 @@ PAUSE_CONTAINER="$PAUSE_CONTAINER_IMAGE:$PAUSE_CONTAINER_VERSION"
 CA_CERTIFICATE_DIRECTORY=/etc/kubernetes/pki
 CA_CERTIFICATE_FILE_PATH=$CA_CERTIFICATE_DIRECTORY/ca.crt
 mkdir -p $CA_CERTIFICATE_DIRECTORY
-if [[ -z "${B64_CLUSTER_CA}" ]] && [[ -z "${APISERVER_ENDPOINT}" ]]; then
+if [[ -z "${DNS_CLUSTER_IP}" ]] || [[ -z "${B64_CLUSTER_CA}" ]] || [[ -z "${APISERVER_ENDPOINT}" ]]; then
     DESCRIBE_CLUSTER_RESULT="/tmp/describe_cluster_result.txt"
 
     # Retry the DescribeCluster API for API_RETRY_ATTEMPTS
@@ -236,7 +237,7 @@ if [[ -z "${B64_CLUSTER_CA}" ]] && [[ -z "${APISERVER_ENDPOINT}" ]]; then
             --region=${AWS_DEFAULT_REGION} \
             --name=${CLUSTER_NAME} \
             --output=text \
-            --query 'cluster.{certificateAuthorityData: certificateAuthority.data, endpoint: endpoint}' > $DESCRIBE_CLUSTER_RESULT || rc=$?
+            --query 'cluster.{certificateAuthorityData: certificateAuthority.data, endpoint: endpoint, kubernetesNetworkConfig: kubernetesNetworkConfig.serviceIpv4Cidr}' > $DESCRIBE_CLUSTER_RESULT || rc=$?
         if [[ $rc -eq 0 ]]; then
             break
         fi
@@ -249,6 +250,7 @@ if [[ -z "${B64_CLUSTER_CA}" ]] && [[ -z "${APISERVER_ENDPOINT}" ]]; then
     done
     B64_CLUSTER_CA=$(cat $DESCRIBE_CLUSTER_RESULT | awk '{print $1}')
     APISERVER_ENDPOINT=$(cat $DESCRIBE_CLUSTER_RESULT | awk '{print $2}')
+    SERVICE_IPV4_CIDR=$(cat $DESCRIBE_CLUSTER_RESULT | awk '{print $3}')
 fi
 
 echo $B64_CLUSTER_CA | base64 -d > $CA_CERTIFICATE_FILE_PATH
@@ -258,15 +260,20 @@ sed -i s,MASTER_ENDPOINT,$APISERVER_ENDPOINT,g /var/lib/kubelet/kubeconfig
 sed -i s,AWS_REGION,$AWS_DEFAULT_REGION,g /var/lib/kubelet/kubeconfig
 ### kubelet.service configuration
 
-if [ -z ${DNS_CLUSTER_IP+x} ]; then
+if [[ -z "${DNS_CLUSTER_IP}" ]]; then
+  if [[ ! -z "${SERVICE_IPV4_CIDR}" ]] && [[ "${SERVICE_IPV4_CIDR}" != "None" ]] ; then
+    #Sets the DNS Cluster IP address that would be chosen from the serviceIpv4Cidr. (x.y.z.10)
+    DNS_CLUSTER_IP=${SERVICE_IPV4_CIDR%.*}.10
+  else
     MAC=$(curl -H "X-aws-ec2-metadata-token: $TOKEN" -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/ -s | head -n 1 | sed 's/\/$//')
     TEN_RANGE=$(curl -H "X-aws-ec2-metadata-token: $TOKEN" -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/$MAC/vpc-ipv4-cidr-blocks | grep -c '^10\..*' || true )
     DNS_CLUSTER_IP=10.100.0.10
     if [[ "$TEN_RANGE" != "0" ]]; then
-        DNS_CLUSTER_IP=172.20.0.10
+      DNS_CLUSTER_IP=172.20.0.10
     fi
+  fi
 else
-    DNS_CLUSTER_IP="${DNS_CLUSTER_IP}"
+  DNS_CLUSTER_IP="${DNS_CLUSTER_IP}"
 fi
 
 KUBELET_CONFIG=/etc/kubernetes/kubelet/kubelet-config.json