Provide sources.list file for DEBIAN_STRETCH class to be able to use "-s stretch"

Otherwise the suite (-s) option is rewritten to a non-existing
DEBIAN_STRETCH class which lacks the corresponding apt sources.list
file, resulting in no Debian mirror available in the chroot.

diff --git a/etc/grml/fai/config/files/etc/apt/sources.list.d/debian.list/DEBIAN_STRETCH b/etc/grml/fai/config/files/etc/apt/sources.list.d/debian.list/DEBIAN_STRETCH
new file mode 100644 (file)
index 0000000..f27cc7f
--- /dev/null
+++ b/etc/grml/fai/config/files/etc/apt/sources.list.d/debian.list/DEBIAN_STRETCH
@@ -0,0 +1,11 @@
+# official debian repository:
+  deb     http://ftp.debian.org/debian/ stretch main contrib non-free
+  deb-src http://ftp.debian.org/debian/ stretch main contrib non-free
+
+# security updates:
+  deb     http://security.debian.org/ stretch/updates main contrib
+  deb-src http://security.debian.org/ stretch/updates main contrib
+
+# backports:
+  deb     http://ftp.debian.org/debian/ stretch-backports main contrib non-free
+  deb-src http://ftp.debian.org/debian/ stretch-backports main contrib non-free