From 8fa2b7a61816cbdfc611f3db9373ec30b21f2915 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Wed, 3 Feb 2021 15:43:12 +0000
Subject: [PATCH] Prevent multiple low zoom renders running together

---
 cookbooks/systemd/resources/service.rb          | 3 +++
 cookbooks/systemd/templates/default/service.erb | 9 +++++++++
 cookbooks/tile/recipes/default.rb               | 3 +++
 3 files changed, 15 insertions(+)

diff --git a/cookbooks/systemd/resources/service.rb b/cookbooks/systemd/resources/service.rb
index 26cce2978..62c959692 100644
--- a/cookbooks/systemd/resources/service.rb
+++ b/cookbooks/systemd/resources/service.rb
@@ -22,7 +22,10 @@ default_action :create
 property :service, String, :name_property => true
 property :dropin, String
 property :description, String
+property :condition_path_exists, [String, Array]
+property :condition_path_exists_glob, [String, Array]
 property :after, [String, Array]
+property :conflicts, [String, Array]
 property :wants, [String, Array]
 property :type, String, :is => %w[simple forking oneshot dbus notify idle]
 property :limit_nofile, Integer
diff --git a/cookbooks/systemd/templates/default/service.erb b/cookbooks/systemd/templates/default/service.erb
index 6d8a603cc..eff7b8308 100644
--- a/cookbooks/systemd/templates/default/service.erb
+++ b/cookbooks/systemd/templates/default/service.erb
@@ -4,9 +4,18 @@
 <% if @description -%>
 Description=<%= @description %>
 <% end -%>
+<% if @condition_path_exists -%>
+ConditionPathExists=<%= Array(@condition_path_exists).join(" ") %>
+<% end -%>
+<% if @condition_path_exists_glob -%>
+ConditionPathExistsGlob=<%= Array(@condition_path_exists_glob).join(" ") %>
+<% end -%>
 <% if @after -%>
 After=<%= Array(@after).join(" ") %>
 <% end -%>
+<% if @conflicts -%>
+Conflicts=<%= Array(@conflicts).join(" ") %>
+<% end -%>
 <% if @wants -%>
 Wants=<%= Array(@wants).join(" ") %>
 <% end -%>
diff --git a/cookbooks/tile/recipes/default.rb b/cookbooks/tile/recipes/default.rb
index 5299a3e38..7d5052fc2 100644
--- a/cookbooks/tile/recipes/default.rb
+++ b/cookbooks/tile/recipes/default.rb
@@ -274,8 +274,10 @@ nodejs_package "carto"
 
 systemd_service "update-lowzoom@" do
   description "Low zoom tile update service for %i layer"
+  conflicts "render-lowzoom.service"
   user "tile"
   exec_start "/bin/bash /usr/local/bin/update-lowzoom-%i"
+  runtime_directory "update-lowzoom-%i"
   private_tmp true
   private_devices true
   private_network true
@@ -578,6 +580,7 @@ end
 
 systemd_service "render-lowzoom" do
   description "Render low zoom tiles"
+  condition_path_exists_glob "!/run/update-lowzoom-*"
   user "tile"
   exec_start "/usr/local/bin/render-lowzoom"
   private_tmp true
-- 
2.39.5