From 2a67fe15cfd49735c38c944cf84481de6d126c6a Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Wed, 23 Sep 2020 16:22:43 +0000
Subject: [PATCH] Add framework for provisioning textfile collectors for
 prometheus

---
 cookbooks/prometheus/recipes/default.rb     | 16 +++-
 cookbooks/prometheus/resources/collector.rb | 81 +++++++++++++++++++++
 2 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 cookbooks/prometheus/resources/collector.rb

diff --git a/cookbooks/prometheus/recipes/default.rb b/cookbooks/prometheus/recipes/default.rb
index 820d46b2c..9df0056be 100644
--- a/cookbooks/prometheus/recipes/default.rb
+++ b/cookbooks/prometheus/recipes/default.rb
@@ -57,7 +57,21 @@ git "/opt/prometheus" do
   group "root"
 end
 
+directory "/etc/prometheus/collectors" do
+  owner "root"
+  group "root"
+  mode "755"
+  recursive true
+end
+
+directory "/var/lib/prometheus/node-exporter" do
+  owner "root"
+  group "root"
+  mode "755"
+  recursive true
+end
+
 prometheus_exporter "node" do
   port 9100
-  options "--collector.ntp --collector.processes --collector.interrupts"
+  options "--collector.ntp --collector.processes --collector.interrupts --collector.textfile.directory=/var/lib/prometheus/node-exporter"
 end
diff --git a/cookbooks/prometheus/resources/collector.rb b/cookbooks/prometheus/resources/collector.rb
new file mode 100644
index 000000000..dc9c995a0
--- /dev/null
+++ b/cookbooks/prometheus/resources/collector.rb
@@ -0,0 +1,81 @@
+#
+# Cookbook:: prometheus
+# Resource:: prometheus_collector
+#
+# Copyright:: 2020, OpenStreetMap Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+default_action :create
+
+property :collector, :kind_of => String, :name_property => true
+property :interval, :kind_of => [Integer, String], :required => [:create]
+property :options, :kind_of => [String, Array]
+property :environment, :kind_of => Hash, :default => {}
+
+action :create do
+  systemd_service service_name do
+    description "Prometheus #{new_resource.collector} collector"
+    user "root"
+    environment new_resource.environment
+    standard_output "file:/var/lib/prometheus/node-exporter/#{new_resource.collector}.new"
+    standard_error "journal"
+    exec_start "#{executable_path} #{executable_options}"
+    exec_start_post "/bin/mv /var/lib/prometheus/node-exporter/#{new_resource.collector}.new /var/lib/prometheus/node-exporter/#{new_resource.collector}.prom"
+    private_tmp true
+    protect_system "strict"
+    protect_home true
+    read_write_paths "/var/lib/prometheus/node-exporter"
+    no_new_privileges true
+  end
+
+  systemd_timer service_name do
+    description "Prometheus #{new_resource.collector} collector"
+    on_boot_sec 60
+    on_unit_active_sec new_resource.interval
+  end
+
+  service "#{service_name}.timer" do
+    action [:enable, :start]
+    subscribes :restart, "systemd_timer[#{service_name}]"
+  end
+end
+
+action :delete do
+  service "#{service_name}.timer" do
+    action [:disable, :stop]
+  end
+
+  systemd_timer service_name do
+    action :delete
+  end
+
+  systemd_service service_name do
+    action :delete
+  end
+end
+
+action_class do
+  def service_name
+    "prometheus-#{new_resource.collector}-collector"
+  end
+
+  def executable_path
+    "/opt/prometheus/collectors/#{new_resource.collector}/#{new_resource.collector}_collector"
+  end
+
+  def executable_options
+    Array(new_resource.options).join(" ")
+  end
+end
-- 
2.43.2