initial changes to use unbound as local dns resolver instead of bind

conf/NetworkManager.conf

@@ -0,0 +1,2 @@
+[main]
+dns=unbound

conf/unbound.conf

@@ -0,0 +1,56 @@
+server:
+      # the working directory.
+      directory: "/etc/unbound"
+
+      # run as the unbound user
+      username: unbound
+
+      verbosity: 0      # uncomment and increase to get more logging.
+      # logfile: "/var/log/unbound.log" # won't work due to apparmor
+      # use-syslog: no
+
+      # By default listen only to localhost
+      #interface: ::1
+      #interface: 127.0.0.1
+      port: 53
+
+      # Only allow localhost to use this Unbound instance.
+      access-control: 127.0.0.1/8 allow
+      access-control: ::1/128 allow
+
+      # Functionality
+      do-ip4: yes
+      do-ip6: yes
+      do-udp: yes
+      do-tcp: yes
+
+      # Performance
+      num-threads: 2
+      cache-min-ttl: 300
+      cache-max-ttl: 86400
+      serve-expired: yes
+      neg-cache-size: 4M
+      msg-cache-size: 50m
+      rrset-cache-size: 100m
+
+      so-reuseport: yes
+      so-rcvbuf: 4m
+      so-sndbuf: 4m
+
+      # Privacy / hardening
+      # hide server info from clients
+      hide-identity: yes
+      hide-version: yes
+      harden-glue: yes
+      harden-dnssec-stripped: yes
+      harden-algo-downgrade: yes
+      harden-large-queries: yes
+      harden-short-bufsize: yes
+
+      rrset-roundrobin: yes
+      minimal-responses: yes
+      identity: "Server" #
+
+remote-control:
+      control-enable: yes
+      control-port: 953

management/dns_update.py

@@ -115,9 +115,9 @@ def do_dns_update(env, force=False):
 			# If this is the only thing that changed?
 			updated_domains.append("DKIM configuration")
 
-	# Clear bind9's DNS cache so our own DNS resolver is up to date.
+	# Clear unbound's DNS cache so our own DNS resolver is up to date.
 	# (ignore errors with trap=True)
-	shell('check_call', ["/usr/sbin/rndc", "flush"], trap=True)
+	shell('check_call', ["/usr/sbin/unbound-control", "reload"], trap=True)
 
 	if len(updated_domains) == 0:
 		# if nothing was updated (except maybe DKIM's files), don't show any output

management/status_checks.py

@@ -22,9 +22,8 @@ from utils import shell, sort_domains, load_env_vars_from_file, load_settings
 
 def get_services():
 	return [
-		{ "name": "Local DNS (bind9)", "port": 53, "public": False, },
+		{ "name": "Local DNS (unbound)", "port": 53, "public": False, },
-		#{ "name": "NSD Control", "port": 8952, "public": False, },
+		{ "name": "Local DNS Control (unbound)", "port": 953, "public": False, },
-		{ "name": "Local DNS Control (bind9/rndc)", "port": 953, "public": False, },
 		{ "name": "Dovecot LMTP LDA", "port": 10026, "public": False, },
 		{ "name": "Postgrey", "port": 10023, "public": False, },
 		{ "name": "Spamassassin", "port": 10025, "public": False, },
@@ -49,15 +48,15 @@ def run_checks(rounded_values, env, output, pool, domains_to_check=None):
 
 	# check that services are running
 	if not run_services_checks(env, output, pool):
-		# If critical services are not running, stop. If bind9 isn't running,
+		# If critical services are not running, stop. If unbound isn't running,
 		# all later DNS checks will timeout and that will take forever to
 		# go through, and if running over the web will cause a fastcgi timeout.
 		return
 
-	# clear bind9's DNS cache so our DNS checks are up to date
+	# clear unbound's DNS cache so our DNS checks are up to date
-	# (ignore errors; if bind9/rndc isn't running we'd already report
+	# (ignore errors; if unbound isn't running we'd already report
 	# that in run_services checks.)
-	shell('check_call', ["/usr/sbin/rndc", "flush"], trap=True)
+	shell('check_call', ["/usr/sbin/unbound-control", "reload"], trap=True)
 
 	run_system_checks(rounded_values, env, output)
 
@@ -793,7 +792,7 @@ def query_dns(qname, rtype, nxdomain='[Not Set]', at=None, as_list=False):
 		qname += "."
 
 	# Use the default nameservers (as defined by the system, which is our locally
-	# running bind server), or if the 'at' argument is specified, use that host
+	# running unbound server), or if the 'at' argument is specified, use that host
 	# as the nameserver.
 	resolver = dns.resolver.get_default_resolver()
 	if at:

setup/dns.sh

@@ -14,7 +14,7 @@ echo "Installing nsd (DNS server)..."
 
 # Prepare nsd's configuration.
 # We configure nsd before installation as we only want it to bind to some addresses
-# and it otherwise will have port / bind conflicts with bind9 used as the local resolver
+# and it otherwise will have port / bind conflicts with unbound used as the local resolver
 mkdir -p /var/run/nsd
 mkdir -p /etc/nsd
 mkdir -p /etc/nsd/zones
@@ -40,7 +40,7 @@ server:
 
 EOF
 
-# Since we have bind9 listening on localhost for locally-generated
+# Since we have unbound listening on localhost for locally-generated
 # DNS queries that require a recursive nameserver, and the system
 # might have other network interfaces for e.g. tunnelling, we have
 # to be specific about the network interfaces that nsd binds to.

setup/system.sh

@@ -310,50 +310,33 @@ fi #NODOC
 # DNS server, which won't work for RBLs. So we really need a local recursive
 # nameserver.
 #
-# We'll install `bind9`, which as packaged for Ubuntu, has DNSSEC enabled by default via "dnssec-validation auto".
+# We'll install unbound, which as packaged for Ubuntu, has DNSSEC enabled by default.
 # We'll have it be bound to 127.0.0.1 so that it does not interfere with
 # the public, recursive nameserver `nsd` bound to the public ethernet interfaces.
-#
-# About the settings:
-#
-# * The listen-on directive in named.conf.options restricts `bind9` to
-#   binding to the loopback interface instead of all interfaces.
-# * The max-recursion-queries directive increases the maximum number of iterative queries.
-#  	If more queries than specified are sent, bind9 returns SERVFAIL. After flushing the cache during system checks,
-#	we ran into the limit thus we are increasing it from 75 (default value) to 100.
-apt_install bind9
 
-if ! grep -q "listen-on " /etc/bind/named.conf.options; then
+# remove bind9 in case it is still there
-	# Add a listen-on directive if it doesn't exist inside the options block.
+apt-get purge -qq -y bind9
-	sed -i "s/^}/\n\tlisten-on { 127.0.0.1; };\n}/" /etc/bind/named.conf.options
-fi
-if ! grep -q "listen-on-v6 " /etc/bind/named.conf.options; then
-	# Add a listen-on-v6 directive if it doesn't exist inside the options block.
-	sed -i "s/^}/\n\tlisten-on-v6 { ::1; };\n}/" /etc/bind/named.conf.options
-else
-	# Modify the listen-on-v6 directive if it does exist
-	sed -i "s/listen-on-v6 { any; }/listen-on-v6 { ::1; }/" /etc/bind/named.conf.options
-fi
 
-if ! grep -q "max-recursion-queries " /etc/bind/named.conf.options; then
+# Install unbound and dns utils (e.g. dig)
-	# Add a max-recursion-queries directive if it doesn't exist inside the options block.
+apt_install unbound python3-unbound bind9-dnsutils
-	sed -i "s/^}/\n\tmax-recursion-queries 100;\n}/" /etc/bind/named.conf.options
-fi
 
-# First we'll disable systemd-resolved's management of resolv.conf and its stub server.
+# Configure unbound
-# Breaking the symlink to /run/systemd/resolve/stub-resolv.conf means
+cp -f conf/unbound.conf /etc/unbound/unbound.conf.d/miabunbound.conf
-# systemd-resolved will read it for DNS servers to use. Put in 127.0.0.1,
+
-# which is where bind9 will be running. Obviously don't do this before
+# Configure network manager
-# installing bind9 or else apt won't be able to resolve a server to
+mkdir /etc/NetworkManager/conf.d
-# download bind9 from.
+cp -f conf/NetworkManager.conf /etc/NetworkManager/conf.d/unbound.conf
-rm -f /etc/resolv.conf
+
-tools/editconf.py /etc/systemd/resolved.conf DNSStubListener=no
+# Modify systemd settings
-echo "nameserver 127.0.0.1" > /etc/resolv.conf
+tools/editconf.py /etc/systemd/resolv.conf \
+	DNS=127.0.0.1 \
+	DNSSEC=yes \
+	DNSStubListener=no
 
 # Restart the DNS services.
 
-restart_service bind9
 systemctl restart systemd-resolved
+systemctl restart unbound
 
 # ### Fail2Ban Service