infra: Provide get-dm-txt

This script (which will become an example) fetches the Debian
ftpmasters' dm.txt file, which lists permissions granted to Debian
Maintainers.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/infra/get-dm-txt b/infra/get-dm-txt
new file mode 100755 (executable)
index 0000000..7902c1c
--- /dev/null
+++ b/infra/get-dm-txt
@@ -0,0 +1,18 @@
+#!/bin/sh
+set -e
+
+cd /srv/dgit.debian.org/data
+
+file=dm.txt
+server=ftp-master.debian.org
+path=$file
+cert=/etc/ssl/certs/$server.pem
+
+with-lock-ex -f $file.lock sh -c "
+       if ! wget --ca-certificate=$cert --ca-directory=/dev/enoent \
+               -O $file.new https://$server/$path >$file.stderr 2>&1; then
+               cat $file.stderr >&2
+               exit 127
+       fi
+       mv -f $file.new $file
+"