guestfs: fix debian13 nsswitch.conf edit

The debian13 guests come with an nsswitch.conf line like this:

hosts:          files myhostname resolve [!UNAVAIL=return]

When we have CONFIG_GUESTFS_HAS_DISTRO_SOURCE_COPY_CAPABILITIES=y
which would be when we have say a debian13 host and a debian13 guest
and the host has a hop1 /etc/apt/sources.list, we copy the host's
sources.list so we can profit from the speedy mirrors you have.

However we need DNS to make sure we can talk to the servers and the
above line prevents that. I had first tried to just remove the UNAVAIL
entry with virt-builder command:

edit /etc/nsswitch.conf:'s/\[!UNAVAIL=return\]//'

But for the life of me this is not taking effect. So just do a brute
force wipe of the file and open code the entire set of lines we want
for debian13 for /etc/nsswitch.conf.

Signed-off-by: Luis Chamberlain <[email protected]>

Author: mcgrof

scripts/bringup_guestfs.sh

@@ -234,14 +234,28 @@ firstboot-command DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=tru
 firstboot-command systemctl start ssh
 _EOT
 	# CONFIG_GUESTFS_COPY_SOURCES_FROM_HOST_TO_GUEST will not work
-	# if etc/nsswitch.conf has a line like this:
+	# if /etc/nsswitch.conf has a line like this:
 	#
 	# hosts:          files myhostname resolve [!UNAVAIL=return] dns
 	#
 	# We need DNS to be used so virb0 will be used for a DNS request
+	# For the life of me I can't get the following line to work with
+	# the virt-builder command and so we do a full edit of the file for now
+	# edit /etc/nsswitch.conf:'s/\[!UNAVAIL=return\]//'
 	if [[ "$CONFIG_GUESTFS_DEBIAN_TRIXIE" == "y" ]]; then
 		cat <<_EOT >>$cmdfile
-edit /etc/nsswitch.conf:'s/^hosts:.*UNAVAIL=return.*dns/hosts: files myhostname resolve dns/'
+write /etc/nsswitch.conf: # kdevops generated /etc/nsswitch.conf
+append-line /etc/nsswitch.conf:passwd:         files
+append-line /etc/nsswitch.conf:group:          files
+append-line /etc/nsswitch.conf:shadow:         files
+append-line /etc/nsswitch.conf:gshadow:        files
+append-line /etc/nsswitch.conf:hosts:          files myhostname resolve dns
+append-line /etc/nsswitch.conf:networks:       files
+append-line /etc/nsswitch.conf:protocols:      db files
+append-line /etc/nsswitch.conf:services:       db files
+append-line /etc/nsswitch.conf:ethers:         db files
+append-line /etc/nsswitch.conf:rpc:            db files
+append-line /etc/nsswitch.conf:netgroup:       nis
 uninstall cloud-init
 write /etc/default/locale:LANG=en_US.UTF-8
 append-line /etc/default/locale:LANGUAGE=en_US:en