From 90cf65550143edb0003250f509f3d07670648ee5 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Thu, 18 Jun 2020 18:47:09 +0100
Subject: [PATCH] Wrap DNS updates with a lock to avoid conflicts

---
 cookbooks/dns/recipes/default.rb               | 1 +
 cookbooks/dns/templates/default/dns-check.erb  | 4 ++++
 cookbooks/dns/templates/default/dns-update.erb | 4 ++++
 3 files changed, 9 insertions(+)

diff --git a/cookbooks/dns/recipes/default.rb b/cookbooks/dns/recipes/default.rb
index 3f44b7fa0..2f045a778 100644
--- a/cookbooks/dns/recipes/default.rb
+++ b/cookbooks/dns/recipes/default.rb
@@ -34,6 +34,7 @@ package %w[
   libyaml-libyaml-perl
   libwww-perl
   libjson-xs-perl
+  lockfile-progs
   sshfp
 ]
 
diff --git a/cookbooks/dns/templates/default/dns-check.erb b/cookbooks/dns/templates/default/dns-check.erb
index 0c88edf42..00b97aa60 100755
--- a/cookbooks/dns/templates/default/dns-check.erb
+++ b/cookbooks/dns/templates/default/dns-check.erb
@@ -5,4 +5,8 @@ export STATUSCAKE_USERNAME="OpenStreetMap"
 export STATUSCAKE_APIKEY="<%= @passwords["statuscake"] %>"
 export PATH=/usr/local/bin:$PATH
 
+lockfile-create --use-pid /var/lib/dns/update || exit 1
+
 make --quiet --jobs --directory=/var/lib/dns update > /dev/null
+
+lockfile-remove /var/lib/dns/update
diff --git a/cookbooks/dns/templates/default/dns-update.erb b/cookbooks/dns/templates/default/dns-update.erb
index 4da924be0..5353d69d4 100755
--- a/cookbooks/dns/templates/default/dns-update.erb
+++ b/cookbooks/dns/templates/default/dns-update.erb
@@ -11,6 +11,8 @@ export PATH=/usr/local/bin:$PATH
 
 cd /var/lib/dns
 
+lockfile-create --use-pid update || exit 1
+
 if [ ! -d .git ]
 then
   git clone /var/lib/git/public/dns.git /var/lib/dns
@@ -19,3 +21,5 @@ fi
 git pull -q
 
 make --jobs update
+
+lockfile-remove update
-- 
2.39.5