Change initial install script order:

1. Ensure we have a compatible package manager
  2. Install required packages for os_check to run (we need dnsutils and grep for this
  3. Try to install FTL
  4. FTL installed? Install installer dependencies and continue as normal - no other dependencies are installed until user has gone through all whiptails

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

automated install/basic-install.sh

@@ -2643,25 +2643,9 @@ main() {
         fi
     fi
 
-    # Check for supported distribution
+    # Check for supported package managers so that we may install dependencies
     package_manager_detect
 
-    # If the setup variable file exists,
-    if [[ -f "${setupVars}" ]]; then
-        # if it's running unattended,
-        if [[ "${runUnattended}" == true ]]; then
-            printf "  %b Performing unattended setup, no whiptail dialogs will be displayed\\n" "${INFO}"
-            # Use the setup variables
-            useUpdateVars=true
-            # also disable debconf-apt-progress dialogs
-            export DEBIAN_FRONTEND="noninteractive"
-        else
-            # If running attended, show the available options (repair/reconfigure)
-            update_dialogs
-        fi
-    fi
-
-    # Start the installer
     # Notify user of package availability
     notify_package_updates_available
 
@@ -2671,12 +2655,39 @@ main() {
     # Check that the installed OS is officially supported - display warning if not
     os_check
 
+    # Check if FTL is installed - do this early on as FTL is a hard dependency for Pi-hole
+    local funcOutput
+    funcOutput=$(get_binary_name) #Store output of get_binary_name here
+    local binary
+    binary="pihole-FTL${funcOutput##*pihole-FTL}" #binary name will be the last line of the output of get_binary_name (it always begins with pihole-FTL)
+    local theRest
+    theRest="${funcOutput%pihole-FTL*}" # Print the rest of get_binary_name's output to display (cut out from first instance of "pihole-FTL")
+    if ! FTLdetect "${binary}" "${theRest}"; then
+        printf "  %b FTL Engine not installed\\n" "${CROSS}"
+        exit 1
+    fi
+
     # Install packages used by this installation script
     install_dependent_packages "${INSTALLER_DEPS[@]}"
 
     # Check if SELinux is Enforcing
     checkSelinux
 
+    # If the setup variable file exists,
+    if [[ -f "${setupVars}" ]]; then
+        # if it's running unattended,
+        if [[ "${runUnattended}" == true ]]; then
+            printf "  %b Performing unattended setup, no whiptail dialogs will be displayed\\n" "${INFO}"
+            # Use the setup variables
+            useUpdateVars=true
+            # also disable debconf-apt-progress dialogs
+            export DEBIAN_FRONTEND="noninteractive"
+        else
+            # If running attended, show the available options (repair/reconfigure)
+            update_dialogs
+        fi
+    fi
+
     if [[ "${useUpdateVars}" == false ]]; then
         # Display welcome dialogs
         welcomeDialogs
@@ -2740,18 +2751,6 @@ main() {
     # Create the pihole user
     create_pihole_user
 
-    # Check if FTL is installed - do this early on as FTL is a hard dependency for Pi-hole
-    local funcOutput
-    funcOutput=$(get_binary_name) #Store output of get_binary_name here
-    local binary
-    binary="pihole-FTL${funcOutput##*pihole-FTL}" #binary name will be the last line of the output of get_binary_name (it always begins with pihole-FTL)
-    local theRest
-    theRest="${funcOutput%pihole-FTL*}" # Print the rest of get_binary_name's output to display (cut out from first instance of "pihole-FTL")
-    if ! FTLdetect "${binary}" "${theRest}"; then
-        printf "  %b FTL Engine not installed\\n" "${CROSS}"
-        exit 1
-    fi
-
     # Install and log everything to a file
     installPihole | tee -a /proc/$$/fd/3