From d9bd6abc4b248f35790183370b7cef2a12f41f85 Mon Sep 17 00:00:00 2001
From: Ian Kelling <iank@fsf.org>
Date: Fri, 28 Jun 2019 15:27:40 -0400
Subject: [PATCH] handle when resolvconf is not installed

---
 newns | 59 +++++++++++++++++++++++++++++++----------------------------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/newns b/newns
index a2d896d..9c9ee67 100755
--- a/newns
+++ b/newns
@@ -48,7 +48,7 @@ Also creates a mount namespace with a cloned /run/resolvconf.
 
 From a normal shell:
 
-If we do create the netns, to join it with a shell, we can do
+If we do create the netns, to join it with a shell, we can do (as root)
 /usr/bin/nsenter --mount=/root/mount_namespaces/NAME --net=/var/run/netns/NAME bash
 
 If you dont care about the mount namespace, you can leave that option off.
@@ -285,35 +285,38 @@ start() {
   ipnn route add default via $network.1
 
   ###### begin setup resolvconf
-  resolv_copy=/root/resolvconf-$nn
+  if [[ -e /run/resolvconf ]]; then # resolvconf probably not installed
+    resolv_copy=/root/resolvconf-$nn
 
-  # this condition should never happen, just coding defensively
-  if mexec mountpoint /run/resolvconf &>/dev/null; then
-    mexec umount /run/resolvconf
-  fi
-  cp -aT /run/resolvconf $resolv_copy
-  if ! mexec mount -o bind $resolv_copy /run/resolvconf; then
-    echo "error: resolv-conf bindmount failed"
-    exit 1
-  fi
-  # if running dnsmasq, we have 127.0.0.1 for dns, but it can't listen on the loopback
-  # in the network namespace, so adjust the address.
-  if mexec [ -s /run/resolvconf/interface/lo.dnsmasq ]; then
-    mexec sed --follow-symlinks -i "s/nameserver 127\..*/nameserver $network.1/" /run/resolvconf/interface/lo.dnsmasq
-    mexec resolvconf -u
-  fi
-  # and in debian based distros at least, it runs with --local-service, and needs a restart
-  # to know about the new local network
-  if [[ $(systemctl --no-pager show -p ActiveState dnsmasq ) == ActiveState=active ]]; then
-    systemctl restart dnsmasq
-  fi
+    # this condition should never happen, just coding defensively
+    if mexec mountpoint /run/resolvconf &>/dev/null; then
+      mexec umount /run/resolvconf
+    fi
+    cp -aT /run/resolvconf $resolv_copy
+    if ! mexec mount -o bind $resolv_copy /run/resolvconf; then
+      echo "error: resolv-conf bindmount failed"
+      exit 1
+    fi
+    # if running dnsmasq, we have 127.0.0.1 for dns, but it can't listen on the loopback
+    # in the network namespace, so adjust the address.
+    if mexec [ -s /run/resolvconf/interface/lo.dnsmasq ]; then
+      mexec sed --follow-symlinks -i "s/nameserver 127\..*/nameserver $network.1/" /run/resolvconf/interface/lo.dnsmasq
+      mexec resolvconf -u
+    fi
+    # and in debian based distros at least, it runs with --local-service, and needs a restart
+    # to know about the new local network
+    if [[ $(systemctl --no-pager show -p ActiveState dnsmasq ) == ActiveState=active ]]; then
+      systemctl restart dnsmasq
+    fi
+
+    # background: if we did this in openvpn's resolv-conf script, we could guard it in
+    # if capsh --print|grep '\bcap_sys_admin\b' &>/dev/null
+    # and we could get $nn by
+    # config_basename=${config%%.*}
+    # config_basename=${config_basename##*/}
+    # but dnsmasq forces us to do it earlier.
 
-  # background: if we did this in openvpn's resolv-conf script, we could guard it in
-  # if capsh --print|grep '\bcap_sys_admin\b' &>/dev/null
-  # and we could get $nn by
-  # config_basename=${config%%.*}
-  # config_basename=${config_basename##*/}
-  # but dnsmasq forces us to do it earlier.
+  fi # end if [[ -e /run/resolvconf ]]
   ######  end setup resolvconf
 
 
-- 
2.30.2