Update install_flux.sh to use kustomize that comes with kubectl.

scripts/install_flux.sh

@@ -6,20 +6,19 @@ trap 'echo ❌ exit at ${0}:${LINENO}, command was: ${BASH_COMMAND} 1>&2' ERR
 #
 # global defaults
 #
-FLUX_SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" > /dev/null && pwd )"
+FLUX_SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null && pwd)"
 FLUX_KUSTOMIZATION="${FLUX_SCRIPT_DIR}/../base/flux"
 REGISTRY_URL=registry1.dso.mil
 FLUX_SECRET=private-registry
 WAIT_TIMEOUT=300
 
-
 #
 # helper functions
 #
 
 # script help message
 function help {
-  cat << EOF
+  cat <<EOF
 usage: $(basename "$0") <arguments>
 -h|--help                - print this help message and exit
 -r|--registry-url        - (optional, default: registry1.dso.mil) registry url to use for flux installation
@@ -32,8 +31,7 @@ EOF
 
 # script check for existing pull secret
 function check_secrets {
-  if kubectl get secrets/"$FLUX_SECRET" -n flux-system > /dev/null 2>&1;
-  then
+  if kubectl get secrets/"$FLUX_SECRET" -n flux-system >/dev/null 2>&1; then
     #the secret exists
     FLUX_SECRET_EXISTS=0
   else
@@ -47,77 +45,84 @@ function check_secrets {
 #
 
 PARAMS=""
-while (( "$#" )); do
-  case "$1" in  
-    # registry username required argument
-    -u|--registry-username)
-      if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
-        REGISTRY_USERNAME=$2
-        shift 2
-      else
-        echo "Error: Argument for $1 is missing" >&2
-        help; exit 1
-      fi
-      ;;
-    # registry password required argument
-    -p|--registry-password)
-      if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
-        REGISTRY_PASSWORD=$2
-        shift 2
-      else
-        echo "Error: Argument for $1 is missing" >&2
-        help; exit 1
-      fi
-      ;;
-    # registry email required argument
-    -e|--registry-email)
-      if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
-        REGISTRY_EMAIL=$2
-        shift 2
-      else
-        echo "Error: Argument for $1 is missing" >&2
-        help; exit 1
-      fi
-      ;;
-    # registry url optional argument
-    -r|--registry-url)
-      if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
-        REGISTRY_URL=$2
-        shift 2
-      else
-        echo "Error: Argument for $1 is missing" >&2
-        help; exit 1
-      fi
-      ;;
-    # wait timeout optional argument
-    -w|--wait-timeout)
-      if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
-        WAIT_TIMEOUT=$2
-        shift 2
-      else
-        echo "Error: Argument for $1 is missing" >&2
-        help; exit 1
-      fi
-      ;;
-    # help flag
-    -h|--help)
-      help; exit 0
-      ;;
-    # Check if private-registry secret exists
-    -s|--use-existing-secret)
-      check_secrets;
-      shift
-      ;;
-    # unsupported flags
-    -*|--*=)
-      echo "Error: Unsupported flag $1" >&2
-      help; exit 1
-      ;;
-    # preserve positional arguments
-    *)
-      PARAMS="$PARAMS $1"
-      shift
-      ;;
+while (("$#")); do
+  case "$1" in
+  # registry username required argument
+  -u | --registry-username)
+    if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
+      REGISTRY_USERNAME=$2
+      shift 2
+    else
+      echo "Error: Argument for $1 is missing" >&2
+      help
+      exit 1
+    fi
+    ;;
+  # registry password required argument
+  -p | --registry-password)
+    if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
+      REGISTRY_PASSWORD=$2
+      shift 2
+    else
+      echo "Error: Argument for $1 is missing" >&2
+      help
+      exit 1
+    fi
+    ;;
+  # registry email required argument
+  -e | --registry-email)
+    if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
+      REGISTRY_EMAIL=$2
+      shift 2
+    else
+      echo "Error: Argument for $1 is missing" >&2
+      help
+      exit 1
+    fi
+    ;;
+  # registry url optional argument
+  -r | --registry-url)
+    if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
+      REGISTRY_URL=$2
+      shift 2
+    else
+      echo "Error: Argument for $1 is missing" >&2
+      help
+      exit 1
+    fi
+    ;;
+  # wait timeout optional argument
+  -w | --wait-timeout)
+    if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
+      WAIT_TIMEOUT=$2
+      shift 2
+    else
+      echo "Error: Argument for $1 is missing" >&2
+      help
+      exit 1
+    fi
+    ;;
+  # help flag
+  -h | --help)
+    help
+    exit 0
+    ;;
+  # Check if private-registry secret exists
+  -s | --use-existing-secret)
+    check_secrets
+    shift
+    ;;
+  # unsupported flags
+  -* | --*=)
+    echo "Error: Unsupported flag $1" >&2
+    help
+    exit 1
+    ;;
+  # preserve positional arguments
+  *)
+    PARAMS="$PARAMS $1"
+    shift
+    ;;
   esac
 done
 
@@ -126,7 +131,8 @@ if [ -z "$FLUX_SECRET_EXISTS" ] || [ "$FLUX_SECRET_EXISTS" -eq 1 ]; then
 
   # check required arguments
   if [ -z "$REGISTRY_USERNAME" ] || [ -z "$REGISTRY_PASSWORD" ]; then
-    help; exit 1
+    help
+    exit 1
   fi
 
   # debug print cli args
@@ -147,9 +153,20 @@ fi
 #
 # install flux
 #
-
 echo "Installing flux from kustomization"
-kustomize build "$FLUX_KUSTOMIZATION" | sed "s/registry1.dso.mil/${REGISTRY_URL}/g" | kubectl apply -f -
+KUBECTL_VERSION=$(kubectl version --client --short | awk -F "v" '{print $NF}')
+KUBECTL_MIN_VERSION="1.21.0"
+
+if [ "$(printf '%s\n' "$KUBECTL_MIN_VERSION" "$KUBECTL_VERSION" | sort -V | head -n1)" = "$KUBECTL_MIN_VERSION" ]; then
+  kubectl kustomize "$FLUX_KUSTOMIZATION" | sed "s/registry1.dso.mil/${REGISTRY_URL}/g" | kubectl apply -f -
+else
+  if [ command -v kustomize ] >/dev/null 2>&1; then
+    echo "Kustomize not found"
+    exit 1
+  else
+    kustomize build "$FLUX_KUSTOMIZATION" | sed "s/registry1.dso.mil/${REGISTRY_URL}/g" | kubectl apply -f -
+  fi
+fi
 
 #
 # verify flux