Supporting resolvconf in the squashfs.

When resolvconf is used in the squashfs, /etc/resolv.conf is a symlink
to the generated version. Depending on the size of the squashfs and
other factors, sometimes we try to write to /etc/resolv.conf while it
still points to nirvana, as resolvconf did not generate it yet.

Instead of being racy and writing to a file which will be regenerated
anyways, let's detect resolvconf and write to its base file instead.

Initial detection idea by Mika Prokop <mika@grml.org>

diff --git a/components/9990-main.sh b/components/9990-main.sh
index 83f087f..85b8a1d 100755 (executable)
--- a/components/9990-main.sh
+++ b/components/9990-main.sh
@@ -178,10 +178,16 @@ Live ()
                fi
        fi
 
-       if [ -f /etc/resolv.conf ] && [ ! -s ${rootmnt}/etc/resolv.conf ]
+       if [ -L /root/etc/resolv.conf ] ; then
+               # assume we have resolvconf
+               DNSFILE="${rootmnt}/etc/resolvconf/resolv.conf.d/base"
+       else
+               DNSFILE="${rootmnt}/etc/resolv.conf"
+       fi
+       if [ -f /etc/resolv.conf ] && [ ! -s ${DNSFILE} ]
        then
-               log_begin_msg "Copying /etc/resolv.conf to ${rootmnt}/etc/resolv.conf"
-               cp -v /etc/resolv.conf ${rootmnt}/etc/resolv.conf
+               log_begin_msg "Copying /etc/resolv.conf to ${DNSFILE}"
+               cp -v /etc/resolv.conf ${DNSFILE}
                log_end_msg
        fi
 

diff --git a/components/9990-netbase.sh b/components/9990-netbase.sh
index af3522f..a32a47b 100755 (executable)
--- a/components/9990-netbase.sh
+++ b/components/9990-netbase.sh
@@ -16,7 +16,12 @@ Netbase ()
        log_begin_msg "Preconfiguring networking"
 
        IFFILE="/root/etc/network/interfaces"
-       DNSFILE="/root/etc/resolv.conf"
+       if [ -L /root/etc/resolv.conf ] ; then
+               # assume we have resolvconf
+               DNSFILE="/root/etc/resolvconf/resolv.conf.d/base"
+       else
+               DNSFILE="/root/etc/resolv.conf"
+       fi
 
        if [ "${STATICIP}" = "frommedia" ] && [ -e "${IFFILE}" ]
        then
@@ -102,7 +107,7 @@ EOF
                        done
                fi
 
-               if [ ! -f /root/etc/resolv.conf ] || [ -z "$(cat /root/etc/resolv.conf)" ]
+               if [ ! -f "${DNSFILE}" ] || [ -z "$(cat ${DNSFILE})" ]
                then
                        if [ -f /netboot.config ]
                        then
@@ -112,7 +117,7 @@ EOF
                                rc_search=$(cat netboot.config | awk '/domain/ { print $3 }')
                                rc_server0="$(cat netboot.config | awk '/dns0/ { print $5 }')"
 
-cat > /root/etc/resolv.conf << EOF
+cat > $DNSFILE << EOF
 search ${rc_search}
 domain ${rc_search}
 nameserver ${rc_server0}
@@ -122,10 +127,10 @@ EOF
 
                                if [ "${rc_server1}" != "0.0.0.0" ]
                                then
-                                       echo "nameserver ${rc_server1}" >> /root/etc/resolv.conf
+                                       echo "nameserver ${rc_server1}" >> $DNSFILE
                                fi
 
-                               cat /root/etc/resolv.conf >> /root/var/log/netboot.config
+                               cat $DNSFILE >> /root/var/log/netboot.config
                        fi
                fi
        fi