I did that and restore the lighttpd.conf for Pihole from a backup (below) and now:
root@DietPi:~# /usr/sbin/lighttpd -tt -f /etc/lighttpd/lighttpd.conf
2021-11-11 15:45:02: configfile.c.2113) command “cat external.conf 2>/dev/null” exited non-zero: 1
2021-11-11 15:45:02: configfile.c.1970) source: /etc/lighttpd/lighttpd.conf line: 68 pos: 14 parser failed somehow near here: (EOL)
\
/etc/lighttpd/lighttpd.conf
# Pi-hole: A black hole for Internet advertisements
# (c) 2017 Pi-hole, LLC (https://pi-hole.net)
# Network-wide ad blocking via your own hardware.
#
# Lighttpd config for Pi-hole
#
# This file is copyright under the latest version of the EUPL.
# Please see LICENSE file for your rights under this license.
###############################################################################
# FILE AUTOMATICALLY OVERWRITTEN BY PI-HOLE INSTALL/UPDATE PROCEDURE. #
# ANY CHANGES MADE TO THIS FILE AFTER INSTALL WILL BE LOST ON THE NEXT UPDATE #
# #
# CHANGES SHOULD BE MADE IN A SEPARATE CONFIG FILE: #
# /etc/lighttpd/external.conf #
###############################################################################
server.modules = (
"mod_access",
"mod_accesslog",
"mod_auth",
"mod_expire",
"mod_redirect",
"mod_setenv",
"mod_rewrite"
)
server.document-root = "/var/www/html"
server.error-handler-404 = "/pihole/index.php"
server.upload-dirs = ( "/var/cache/lighttpd/uploads" )
server.errorlog = "/var/log/lighttpd/error.log"
server.pid-file = "/run/lighttpd.pid"
server.username = "www-data"
server.groupname = "www-data"
server.port = 80
accesslog.filename = "/var/log/lighttpd/access.log"
accesslog.format = "%{%s}t|%V|%r|%s|%b"
index-file.names = ( "index.php", "index.html", "index.lighttpd.html" )
url.access-deny = ( "~", ".inc", ".md", ".yml", ".ini" )
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )
mimetype.assign = (
".ico" => "image/x-icon",
".jpeg" => "image/jpeg",
".jpg" => "image/jpeg",
".png" => "image/png",
".svg" => "image/svg+xml",
".css" => "text/css; charset=utf-8",
".html" => "text/html; charset=utf-8",
".js" => "text/javascript; charset=utf-8",
".json" => "application/json; charset=utf-8",
".map" => "application/json; charset=utf-8",
".txt" => "text/plain; charset=utf-8",
".eot" => "application/vnd.ms-fontobject",
".otf" => "font/otf",
".ttc" => "font/collection",
".ttf" => "font/ttf",
".woff" => "font/woff",
".woff2" => "font/woff2"
)
# Add user chosen options held in external file
# This uses include_shell instead of an include wildcard for compatibility
include_shell "cat external.conf 2>/dev/null"
# default listening port for IPv6 falls back to the IPv4 port
include_shell "/usr/share/lighttpd/use-ipv6.pl " + server.port
# Prevent Lighttpd from enabling Let's Encrypt SSL for every blocked domain
#include_shell "/usr/share/lighttpd/include-conf-enabled.pl"
include_shell "find /etc/lighttpd/conf-enabled -name '*.conf' -a ! -name 'letsencrypt.conf' -printf 'include \"%p\"\n' 2>/dev/null"
# If the URL starts with /admin, it is the Web interface
$HTTP["url"] =~ "^/admin/" {
# Create a response header for debugging using curl -I
setenv.add-response-header = (
"X-Pi-hole" => "The Pi-hole Web interface is working!",
"X-Frame-Options" => "DENY"
)
}
# Block . files from being served, such as .git, .github, .gitignore
$HTTP["url"] =~ "^/admin/\.(.*)" {
url.access-deny = ("")
}
# allow teleporter iframe on settings page
$HTTP["url"] =~ "/teleporter\.php$" {
$HTTP["referer"] =~ "/admin/settings\.php" {
setenv.add-response-header = ( "X-Frame-Options" => "SAMEORIGIN" )
}
}
# Default expire header
expire.url = ( "" => "access plus 0 seconds" )