Merge pull request #1600 from pi-hole/tweak/OnlyDownloadFTLNew

Only download FTL if a newer version than currently installed is detected (or if no version is detected)

automated install/basic-install.sh

@@ -1758,7 +1758,7 @@ FTLinstall() {
   local binary="${1}"
   local latesttag
   local orig_dir
-  local str="Installing FTL"
+  local str="Downloading and Installing FTL"
   echo -ne "  ${INFO} ${str}..."
 
   # Get the current working directory
@@ -1771,6 +1771,7 @@ FTLinstall() {
     echo -e "  ${COL_LIGHT_RED}Error: Unable to get latest release location from GitHub${COL_NC}"
     return 1
   fi
+
   # If the download worked,
   if curl -sSL --fail "https://github.com/pi-hole/FTL/releases/download/${latesttag%$'\r'}/${binary}" -o "/tmp/${binary}"; then
     # get sha1 of the binary we just downloaded for verification.
@@ -1813,7 +1814,7 @@ FTLinstall() {
 # Detect suitable FTL binary platform
 FTLdetect() {
   echo ""
-  echo -e "  ${INFO} Downloading latest version of FTL..."
+  echo -e "  ${INFO} FTL Checks..."
 
   # Local, named variables
   local machine
@@ -1876,8 +1877,37 @@ FTLdetect() {
     binary="pihole-FTL-linux-x86_32"
   fi
 
-  # Install FTL
-  FTLinstall "${binary}" || return 1
+  #In the next section we check to see if FTL is already installed (in case of pihole -r).
+  #If the installed version matches the latest version, then check the installed sha1sum of the binary vs the remote sha1sum. If they do not match, then download
+  echo -e "  ${INFO} Checking for existing FTL binary..."
+
+  local ftlLoc=$(which pihole-FTL)
+
+  if [[ ${ftlLoc} ]]; then
+    local FTLversion=$(/usr/bin/pihole-FTL tag)
+	  local FTLlatesttag=$(curl -sI https://github.com/pi-hole/FTL/releases/latest | grep 'Location' | awk -F '/' '{print $NF}' | tr -d '\r\n')
+
+	  if [[ "${FTLversion}" != "${FTLlatesttag}" ]]; then
+		  # Install FTL
+      FTLinstall "${binary}" || return 1
+	  else
+	    echo -e "  ${INFO} Latest FTL Binary already installed (${FTLlatesttag}). Confirming Checksum..."
+
+	    local remoteSha1=$(curl -sSL --fail "https://github.com/pi-hole/FTL/releases/download/${FTLversion%$'\r'}/${binary}.sha1" | cut -d ' ' -f 1)
+	    local localSha1=$(sha1sum "$(which pihole-FTL)" | cut -d ' ' -f 1)
+
+	    if [[ "${remoteSha1}" != "${localSha1}" ]]; then
+	      echo -e "  ${INFO} Corruption detected..."
+	      FTLinstall "${binary}" || return 1
+	    else
+	      echo -e "  ${INFO} Checksum correct. No need to download!"
+	    fi
+	  fi
+	else
+	  # Install FTL
+    FTLinstall "${binary}" || return 1
+  fi
+
 
 }