From 80c458bfe9ac5f7fb7db6c83a223a36ed54736eb Mon Sep 17 00:00:00 2001
From: Russell Bryant <rbryant@redhat.com>
Date: Thu, 23 Jan 2020 14:59:35 -0500
Subject: [PATCH] baremetal: Fix bootstrap local DNS for IPv6

This was previously done with an option to dhclient, but this doesn't
work when doing DHCPv6.  Switch to a script run by NetworkManager to do
the same thing.

This matches the same approach moved to by the MCO in this PR:

https://github.com/openshift/machine-config-operator/pull/1396
---
 .../dispatcher.d/30-local-dns-prepender       | 20 +++++++++++++++++++
 .../baremetal/files/etc/dhcp/dhclient.conf    |  7 -------
 pkg/asset/ignition/bootstrap/bootstrap.go     |  3 ++-
 3 files changed, 22 insertions(+), 8 deletions(-)
 create mode 100755 data/data/bootstrap/baremetal/files/etc/NetworkManager/dispatcher.d/30-local-dns-prepender
 delete mode 100644 data/data/bootstrap/baremetal/files/etc/dhcp/dhclient.conf

diff --git a/data/data/bootstrap/baremetal/files/etc/NetworkManager/dispatcher.d/30-local-dns-prepender b/data/data/bootstrap/baremetal/files/etc/NetworkManager/dispatcher.d/30-local-dns-prepender
new file mode 100755
index 00000000000..307e86ae696
--- /dev/null
+++ b/data/data/bootstrap/baremetal/files/etc/NetworkManager/dispatcher.d/30-local-dns-prepender
@@ -0,0 +1,20 @@
+#!/bin/bash
+IFACE=$1
+STATUS=$2
+case "$STATUS" in
+    up)
+    logger -s "NM local-dns-prepender triggered by ${1} ${2}."
+    DNS_IP="127.0.0.1"
+    set +e
+    logger -s "NM local-dns-prepender: Checking if local DNS IP is the first entry in resolv.conf"
+    if grep nameserver /etc/resolv.conf | head -n 1 | grep -q "$DNS_IP" ; then
+        logger -s "NM local-dns-prepender: local DNS IP already is the first entry in resolv.conf"
+        exit 0
+    else
+        logger -s "NM local-dns-prepender: Looking for '# Generated by NetworkManager' in /etc/resolv.conf to place 'nameserver $DNS_IP'"
+        sed -i "/^# Generated by.*$/a nameserver $DNS_IP" /etc/resolv.conf
+    fi
+    ;;
+    *)
+    ;;
+esac
diff --git a/data/data/bootstrap/baremetal/files/etc/dhcp/dhclient.conf b/data/data/bootstrap/baremetal/files/etc/dhcp/dhclient.conf
deleted file mode 100644
index f46c0f6cc10..00000000000
--- a/data/data/bootstrap/baremetal/files/etc/dhcp/dhclient.conf
+++ /dev/null
@@ -1,7 +0,0 @@
-# Specifies that the bootstrap node should use its own local DNS server for
-# name resolution.
-#
-# For more information, see installer/data/data/bootstrap/baremetal/README.md
-#
-
-prepend domain-name-servers 127.0.0.1;
diff --git a/pkg/asset/ignition/bootstrap/bootstrap.go b/pkg/asset/ignition/bootstrap/bootstrap.go
index e3ac199d286..af43aa6b369 100644
--- a/pkg/asset/ignition/bootstrap/bootstrap.go
+++ b/pkg/asset/ignition/bootstrap/bootstrap.go
@@ -292,10 +292,11 @@ func (a *Bootstrap) addStorageFiles(base string, uri string, templateData *boots
 	}
 
 	filename := path.Base(uri)
+	parentDir := path.Base(path.Dir(uri))
 
 	var mode int
 	appendToFile := false
-	if path.Base(path.Dir(uri)) == "bin" {
+	if parentDir == "bin" || parentDir == "dispatcher.d" {
 		mode = 0555
 	} else if filename == "motd" {
 		mode = 0644