Normalize GKE identifiers in snippets

Author: lsierant

scripts/dev/contexts/funcs/gke

@@ -1,4 +1,7 @@
-# Function to normalize identifier for K8s naming requirements
+# Function to normalize identifier to contain only alphanumeric characters.
+# It's also cutting the string in the middle if exceeds max_len.
+# Example:
+#   normalize_identifier "mongodb_kubernetes_1.4.0_68c913f767d52d00076a2698" 25 -> mongodb-kubex2d00076a2698
 normalize_identifier() {
     local str=$1
     local max_len=$(($2 - 1))
@@ -9,7 +12,7 @@ normalize_identifier() {
 
     # Truncate to ${max_len} chars by cutting from middle
     if [[ ${#str} -gt ${max_len} ]]; then
-        half_idx=$((max_len / 2 - 1))
+        half_idx=$((max_len / 2))
         local start_part="${str:0:${half_idx}}"
         local end_part="${str: -${half_idx}}"
         str="${start_part}x${end_part}"
@@ -19,12 +22,12 @@ normalize_identifier() {
     echo -n "${str}"
 }
 
-# for prerelease builds we have:
+# for prerelease tag builds we have:
 # version_id=mongodb_kubernetes_1.4.0_68c913f767d52d00076a2698-9041 (len=54)
-# k8s cluster name prefix is: k8s-mdb-0- (len=10)
-# K8S_CLUSTER_PREFIX must be shorter than 30 to make the final
-# gke identifier shorter than 40 characters
+# k8s cluster name prefix: k8s-mdb-0- (len=10)
+# random suffix: -1234 (len=5)
+# K8S_CLUSTER_PREFIX must be shorter than 25 to make the final
+# gke identifier shorter than 40 characters.
 create_k8s_cluster_suffix() {
-  echo -n "$(normalize_identifier "${K8S_CLUSTER_SUFFIX:-"-${version_id}-${RANDOM}"}" 28)"
+  echo -n "$(normalize_identifier "${K8S_CLUSTER_SUFFIX:-"-${version_id}-${RANDOM}"}" 25)"
 }
-