Merge ~enr0n/ubuntu/+source/systemd:ubuntu-kinetic into ~ubuntu-core-dev/ubuntu/+source/systemd:ubuntu-kinetic

[Nick Rosbrook]

When the systemd-resolved package split was merged from Debian, we missed some /etc/resolv.conf logic from systemd.postinst that was Ubuntu-specific. This caused regressions, including in image builds. In fact, the missing logic was added to fix a similar issue years ago (LP: #1712283).

[Steve Langasek (vorlon)]

If this worked before, it should work again...

review: Approve

diff --git a/debian/changelog b/debian/changelog
index 6dd0804..28bfe73 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,20 @@
+systemd (251.4-1ubuntu4) kinetic; urgency=medium
+
+  * debian/systemd-resolved.postinst: copy existing /etc/resolv.conf on new installs (LP: #1988772)
+    Commit 20bc8a37fa ("Always setup /etc/resolv.conf on new installations.")
+    added logic to copy any existing /etc/resolv.conf to
+    /run/systemd/resolve/stub-resolv.conf before creating the final symlink.
+    When we merged the systemd-resolved package split changes from Debian,
+    this logic was not replicated, which has caused regressions.
+    Move the necessary pieces from systemd.postint to systemd-resolved.postinst
+    to maintain the previous /etc/resolv.conf logic.
+    Files:
+    - debian/systemd-resolved.postinst
+    - debian/systemd.postinst
+    https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=a34a768a929921978a67ef2192ee787255400ee5
+
+ -- Nick Rosbrook <[e-mail]>  Tue, 06 Sep 2022 19:39:59 -0400
+
 systemd (251.4-1ubuntu3) kinetic; urgency=medium
 
   * Fix version of backported sd_hwdb_new_from_path symbol.
diff --git a/debian/systemd-resolved.postinst b/debian/systemd-resolved.postinst
index e6beb29..eea56d8 100644
--- a/debian/systemd-resolved.postinst
+++ b/debian/systemd-resolved.postinst
@@ -25,10 +25,12 @@ if [ "$1" = configure ] && [ -z "$2" ]; then
     _adopt_conffile /etc/systemd/resolved.conf systemd-resolved
 fi
 
-if [ "$1" = configure ] && dpkg --compare-versions "$2" lt 251.4-1ubuntu2; then
+if [ "$1" = configure ] && dpkg --compare-versions "$2" lt 251.4-1ubuntu4; then
     if [ "$(readlink "/etc/resolv.conf")" != "../run/systemd/resolve/stub-resolv.conf" ] && [ "$(readlink "/etc/resolv.conf")" != "/run/systemd/resolve/stub-resolv.conf" ]; then
         echo "Converting /etc/resolv.conf to a symlink to /run/systemd/resolve/stub-resolv.conf..."
+        mkdir -p "/run/systemd/resolve"
         if [ -f "/etc/resolv.conf" ]; then
+            cp "/etc/resolv.conf" "/run/systemd/resolve/stub-resolv.conf"
             mv "/etc/resolv.conf" "/etc/.resolv.conf.systemd-resolved.bak" || echo "Cannot take a backup of /etc/resolv.conf."
         fi
         ln -sf ../run/systemd/resolve/stub-resolv.conf "/etc/resolv.conf" || echo "Cannot install symlink from /etc/resolv.conf to ../run/systemd/resolve/stub-resolv.conf"
diff --git a/debian/systemd.postinst b/debian/systemd.postinst
index 63e78ca..ec91aa8 100644
--- a/debian/systemd.postinst
+++ b/debian/systemd.postinst
@@ -60,17 +60,6 @@ if dpkg --compare-versions "$2" lt "234-2ubuntu11~"; then
         fi
 fi
 
-# Use stub resolve.conf by default on new installs
-if [ -z "$2" ]; then
-    mkdir -p /run/systemd/resolve
-    if [ -e /etc/resolv.conf ]; then
-            cp /etc/resolv.conf /run/systemd/resolve/stub-resolv.conf
-    fi
-    # If /etc/resolv.conf is a bind-mount, moving or replacing
-    # /etc/resolv.conf may fail
-    ln -snf ../run/systemd/resolve/stub-resolv.conf /etc/resolv.conf || true
-fi
-
 # Enable systemd-pstore by default on new installs and upgrades, see #952767
 if dpkg --compare-versions "$2" lt "245.4-4~"; then
     systemctl enable systemd-pstore.service || true