package update

build/deb/postinst

@@ -1,20 +1,35 @@
 #!/bin/sh
 # postinst — shared by the twiy and twiy-raweb packages.
 #
-# Pristine configs and the default site ship under /usr/share/twiy/defaults
-# (owned/tracked by dpkg), NOT under the live /nginx and /hostdata trees. We
-# seed the live trees from the stash here:
-#   - target missing  -> install the packaged copy
-#   - target present  -> leave it untouched; drop our copy as <file>.new
-# Because dpkg does not track the live files, an install or upgrade never
-# overwrites a config the admin has edited (e.g. you get nginx.conf.new, not a
-# clobbered nginx.conf).
+# Config files live under /nginx but are NOT tracked by dpkg. The package
+# ships an empty /nginx skeleton (so dpkg keeps the dirs across upgrades) plus
+# a pristine copy of every config under /usr/share/twiy/defaults/nginx. We
+# place configs from that stash here and NEVER overwrite a file that already
+# exists — our copy is dropped beside it as <file>.new instead (e.g.
+# nginx.conf.new). An upgrade therefore never changes an admin-edited config.
+#
+# /hostdata is left entirely to the admin: we only make sure the dir exists,
+# and we never touch or remove its contents.
 
 set -e
 
-# nginx runtime user (idempotent).
 useradd -r -s /bin/false nginx 2>/dev/null || true
 
+# Existing dirs are left exactly as they are (mkdir -p is a no-op then).
+mkdir -p /nginx /hostdata
+
+# Migration: older releases shipped /nginx/* as dpkg-tracked files, so the
+# upgrade unpack deletes them before this script runs. preinst stashed a copy
+# first — restore it now, without clobbering anything already present.
+if [ -d /var/backups/twiy-nginx ]; then
+    cp -an /var/backups/twiy-nginx/. /nginx/ 2>/dev/null || true
+    rm -rf /var/backups/twiy-nginx
+fi
+
+# Seed packaged defaults:
+#   - target absent          -> install it
+#   - target present, differs -> keep theirs, drop ours as <file>.new
+#   - target present, same    -> do nothing
 seed_tree() {
     stash="$1"
     target="$2"
@@ -24,21 +39,16 @@ seed_tree() {
         dst="$target/$rel"
         install -d "$(dirname "$dst")"
         if [ -e "$dst" ]; then
-            cp -p "$src" "$dst.new"   # keep admin's file; offer ours as .new
+            cmp -s "$src" "$dst" || cp -p "$src" "$dst.new"
         else
             cp -p "$src" "$dst"
         fi
     done
 }
+seed_tree /usr/share/twiy/defaults/nginx /nginx
 
-seed_tree /usr/share/twiy/defaults/nginx    /nginx
-seed_tree /usr/share/twiy/defaults/hostdata /hostdata
-
-# Empty include dirs referenced by nginx.conf (`include conf.d/*;`) that ship
-# with no files of their own.
 install -d /nginx/conf.d /nginx/config
 install -d -o nginx -g nginx -m 0755 /var/log/nginx
-
 chown -R nginx:nginx /var/log/nginx /nginx 2>/dev/null || true
 
 systemctl daemon-reload  2>/dev/null || true