Merge ~andreserl/maas:lp1696771_snap_preseeds_2.4 into maas:2.4

[Andres Rodriguez]

Backport a02dfe2. LP: #1696771 - Allow overriding preseeds in SNAP_DATA/preseeds & provide template files

[Andres Rodriguez (andreserl)]

selfie!

review: Approve

diff --git a/snap/conf/empty.tgt b/snap/conf/empty.tgt
 deleted file mode 100644
index e69de29..0000000
--- a/snap/conf/empty.tgt
+++ /dev/null
diff --git a/snap/hooks/configure b/snap/hooks/configure
index 258943e..bbc8c89 100755
--- a/snap/hooks/configure
+++ b/snap/hooks/configure
@@ -12,10 +12,18 @@ mkdir -p "$SNAP_COMMON/proxy/cache"
 chown -R nobody:nogroup "$SNAP_COMMON/proxy/cache"
 mkdir -p "$SNAP_COMMON/proxy/spool"
 chown -R nobody:nogroup "$SNAP_COMMON/proxy/spool"
+mkdir -p "$SNAP_DATA/preseeds"
 mkdir -p "$SNAP_DATA/bind"
 mkdir -p "$SNAP_DATA/proxy"
 mkdir -p "$SNAP_DATA/supervisord"
 mkdir -p "$SNAP_DATA/var/lib/maas"
 
+# Always overwrite sample preseeds to ensure samples are up-to-date in case
+# we do changes that need to be reflected.
+cp "$SNAP/etc/maas/preseeds/curtin_userdata" "$SNAP_DATA/preseeds/curtin_userdata.sample"
+cp "$SNAP/etc/maas/preseeds/curtin_userdata_centos" "$SNAP_DATA/preseeds/curtin_userdata_centos.sample"
+cp "$SNAP/etc/maas/preseeds/curtin_userdata_custom" "$SNAP_DATA/preseeds/curtin_userdata_custom.sample"
+cp "$SNAP/etc/maas/preseeds/curtin_userdata_windows" "$SNAP_DATA/preseeds/curtin_userdata_windows.sample"
+
 # Perform migrations. Does nothing in 'rack' or 'none' mode.
 exec "$SNAP/command-maas.wrapper" migrate --configure
diff --git a/src/maasserver/djangosettings/snappy.py b/src/maasserver/djangosettings/snappy.py
index 59dcebd..7648e00 100644
--- a/src/maasserver/djangosettings/snappy.py
+++ b/src/maasserver/djangosettings/snappy.py
@@ -25,5 +25,6 @@ STATIC_ROOT = os.path.join(
 
 # Override the preseed locations.
 PRESEED_TEMPLATE_LOCATIONS = (
+    os.path.join(os.environ['SNAP_DATA'], 'preseeds'),
     os.path.join(os.environ['SNAP'], 'etc', 'maas', 'preseeds'),
     )