From: Petr Tesarik <ptesarik@suse.com>
Date: Thu, 14 Nov 2019 19:13:39 +0100
Subject: Improve the handling of NSS
References: bsc#1021846
Upstream: merged
Git-commit 598d7517ccbbf29dc51e0a9c14146722d2324731

The current code mostly works, but can be improved in two ways:

1. Only the 'hosts' database is really needed in the kdump
   environment, and its settings should be copied from the running
   system. The openSSH client also needs 'passwd' (and maybe
   'group'), but it is not necessary to handle fancy setups (such
   as NIS or AD). The client merely requires that UID 0 can be
   translated to a user name. The 'file' service is more than
   sufficient for that purpose.

2. The NSS configuration file may not contain configuration of all
   categories. If configuration for a given category is missing,
   glibc will use a default setting, but kdump will not install
   the corresponding modules. Fix it by adding the glibc default
   to the configuration file explicitly if needed.

Signed-off-by: Petr Tesarik <ptesarik@suse.com>

---
 init/setup-kdump.functions |   22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

--- a/init/setup-kdump.functions
+++ b/init/setup-kdump.functions
@@ -892,8 +892,6 @@ function kdump_modify_config()						   #
             KDUMP_SAVEDIR="${KDUMP_SAVEDIR}file://${kdump_Realpath[i]}"
 	elif [ "$protocol" != "srcfile" ] ; then
             KDUMP_SAVEDIR="${KDUMP_SAVEDIR}${kdump_URL[i]}"
-            cp /etc/hosts "${dest}/etc"
-            grep '^hosts:' /etc/nsswitch.conf > "${dest}/etc/nsswitch.conf"
 	fi
 
 	#
@@ -919,6 +917,26 @@ function kdump_modify_config()						   #
 	KDUMP_REQUIRED_PROGRAMS="$KDUMP_REQUIRED_PROGRAMS ssh"
     fi
 
+    # make sure NSS works somehow
+    cp /etc/hosts "${dest}/etc"
+    { cat <<-EOF
+	passwd: files
+	shadow: files
+	group: files
+EOF
+      grep '^[[:space:]]*hosts:' /etc/nsswitch.conf \
+	  || echo 'hosts: dns [!UNAVAIL=return] files'
+    } > "${dest}/etc/nsswitch.conf"
+
+    # install necessary NSS modules
+    local _nssmods=$(
+	sed -e 's/#.*//; s/^[^:]*://; s/\[[^]]*\]//' \
+	    "${dest}/etc/nsswitch.conf" \
+	    | tr -s '[:space:]' '\n' | sort -u | tr '\n' '|' )
+    _nssmods=${_nssmods#|}
+    _nssmods=${_nssmods%|}
+    inst_libdir_file -n "/libnss_($_nssmods)" 'libnss_*.so*'
+
     #
     # dump the configuration file, modifying:
     #   KDUMP_SAVEDIR  -> resolved path