Merge pull request #3596 from pi-hole/tweak/wherecheck

Wrap entire function in the check for the ENVVAR, add `ns1.pi-hole.net` to `dig` check.

automated install/basic-install.sh

@@ -175,6 +175,7 @@ is_command() {
 }
 
 os_check() {
+    if [ "$PIHOLE_SKIP_OS_CHECK" != true ]; then
         # This function gets a list of supported OS versions from a TXT record at versions.pi-hole.net
         # and determines whether or not the script is running on one of those systems
         local remote_os_domain valid_os valid_version detected_os_pretty detected_os detected_version display_warning
@@ -187,7 +188,7 @@ os_check() {
         detected_os="${detected_os_pretty%% *}"
         detected_version=$(cat /etc/*release | grep VERSION_ID | cut -d '=' -f2- | tr -d '"')
 
-    IFS=" " read -r -a supportedOS < <(dig +short -t txt ${remote_os_domain} | tr -d '"')
+        IFS=" " read -r -a supportedOS < <(dig +short -t txt ${remote_os_domain} @ns1.pi-hole.net | tr -d '"')
 
         for i in "${supportedOS[@]}"
         do
@@ -212,22 +213,27 @@ os_check() {
             display_warning=false
         fi
 
-    if [ "$display_warning" = true ] && [ "$PIHOLE_SKIP_OS_CHECK" != true ]; then
+        if [ "$display_warning" = true ]; then
             printf "  %b %bUnsupported OS detected%b\\n" "${CROSS}" "${COL_LIGHT_RED}" "${COL_NC}"
             printf "      https://docs.pi-hole.net/main/prerequesites/#supported-operating-systems\\n"
             printf "\\n"
-        printf "      This check can be skipped by setting the environment variable %bPIHOLE_SKIP_OS_CHECK%b to %btrue%b\\n" "${COL_LIGHT_RED}" "${COL_NC}" "${COL_LIGHT_RED}" "${COL_NC}"
-        printf "      e.g: 'sudo PIHOLE_SKIP_OS_CHECK=true curl -sSL https://install.pi-hole.net | bash'\\n"
-        printf "      or   'sudo PIHOLE_SKIP_OS_CHECK=true pihole -up'\\n"
-        printf "      By setting this variable to true you acknowledge there may be issues with Pi-hole during or after the install\\n"
+            printf "      e.g: If you are seeing this message on a fresh install, you can run:\\n"
+            printf "             'curl -sSL https://install.pi-hole.net | PIHOLE_SKIP_OS_CHECK=true sudo -E bash'\\n"
+            printf "\\n"
+            printf "           If you are seeing this message after having run pihole -up:\\n"
+            printf "             'PIHOLE_SKIP_OS_CHECK=true sudo -E pihole -r'\\n"
+            printf "           (In this case, your previous run of pihole -up will have already updated the local repository)\\n"
+            printf "\\n"
             printf "      If that is the case, you can feel free to ask the community on Discourse with the %bCommunity Help%b category:\\n" "${COL_LIGHT_RED}" "${COL_NC}"
             printf "      https://discourse.pi-hole.net/c/bugs-problems-issues/community-help/\\n"
             exit 1
-    elif [ "$display_warning" = true ] && [ "$PIHOLE_SKIP_OS_CHECK" = true ]; then
-        printf "  %b %bUnsupported OS detected%b. PIHOLE_SKIP_OS_CHECK env variable set to true - installer will continue\\n" "${INFO}" "${COL_LIGHT_RED}" "${COL_NC}"
+
         else
             printf "  %b %bSupported OS detected%b\\n" "${TICK}" "${COL_LIGHT_GREEN}" "${COL_NC}"
         fi
+    else
+        printf "  %b %bPIHOLE_SKIP_OS_CHECK env variable set to true - installer will continue%b\\n" "${INFO}" "${COL_LIGHT_GREEN}" "${COL_NC}"
+    fi
 }
 
 # Compatibility