Render jmx.yaml template based on data input

After multiple passes at attempting to cover all cases of inclusion of instance
details into a given YAML file, this lays the foundation for leaving the details
up to the end-user to implement the instance hash, instead of trying to capture
each possible flag.
This should help future-proof the recipe and template, so any new flags can be
appended as data.

See #88, #93 and fixes #116, #121.

Tests and examples updated.

.kitchen.yml

@@ -69,13 +69,30 @@ suites:
       application_key: alsonotnil
       jmx:
         instances:
-          - server: localhost
+          - host: localhost
             port: 9999
             extra_key: extra_val
-            include:
-              - domain: domain0
-              - domain: domain1
-            exclude: []
+            conf:
+              - include:
+                  domain: domain0
+                  type: ThreadPool
+                  bean: tomcat_bean
+                  attributes:
+                    maxThreads:
+                      alias: tomcat.threads.max
+                      metric_type: gauge
+                    bytesReceived:
+                      alias: tomcat.bytes_rcvd
+                      metric_type: counter
+                include:
+                  domain: org.apache.cassandra.db
+                  attributes:
+                    - BloomFilterDiskSpaceUsed
+                    - Capacity
+                  bean_name: com.datadoghq.test:type=BeanType,tag1=my_bean_name
+                  foo: bar
+                exclude:
+                - domain: evil_domain
 
 - name: dd-agent-mongo
   run_list:

recipes/jmx.rb

@@ -1,5 +1,22 @@
 include_recipe 'datadog::dd-agent'
 
+# Build a data structure with configuration.
+# @see https://github.com/DataDog/dd-agent/blob/master/conf.d/jmx.yaml.example JMX Example
+# @example
+#   node.override['datadog']['jmx']['instances'] = [
+#     {
+#       'host' => 'localhost',
+#       'port' => '7199',
+#       'name' 'prod_jmx_app',
+#       'conf' => [
+#         'include' => {
+#           'attributes' => ['Capacity', 'Used'],
+#           'bean_name' => 'com.datadoghq.test:type=BeanType,tag1=my_bean_name',
+#           'domain' => 'com.datadoghq.test'
+#         }
+#       ]
+#     }
+#   ]
 datadog_monitor 'jmx' do
   instances node['datadog']['jmx']['instances']
 end

templates/default/jmx.yaml.erb

@@ -1,48 +1,5 @@
-<% excluded_keys = ["host", "server", "conf", "include", "exclude"] -%>
-instances:
-<% @instances.each do |i| -%>
-  - host: <%= i["server"] %>
-    <% (i.keys - excluded_keys).each do |key| -%>
-    <%= key %>: <%= i[key] %>
-    <% end -%>
-  <% if i.key?("include") || i.key?("exclude") -%>
-    conf:
-      <% i["include"].each do |c| -%>
-      - include:
-          <% if c.key?("domain") -%>
-          domain: <%= c["domain"] %>
-          <% end -%>
-          <% if c.key?("bean") -%>
-          bean: <%= c["bean"] %>
-          <% end -%>
-          <% if c.key?("attributes") -%>
-          attribute:
-            <% c["attributes"].each do |a| -%>
-            attribute<%= c["attributes"].index(a) %>:
-              metric_type: <%= a["metric_type"] %>
-              alias: <%= a["alias"] %>
-            <% end -%>
-          <% end -%>
-      <% end -%>
-      <% i["exclude"].each do |c| -%>
-      - exclude:
-          <% if c.key?("domain") -%>
-          domain: <%= c["domain"] %>
-          <% end -%>
-          <% if c.key?("bean") -%>
-          bean: <%= c["bean"] %>
-          <% end -%>
-          <% if c.key?("attributes") -%>
-          attribute:
-            <% c["attributes"].each do |a| -%>
-            attribute<%= c["attributes"].index(a) %>:
-              metric_type: <%= a["metric_type"] %>
-              alias: <%= a["alias"] %>
-            <% end -%>
-          <% end -%>
-      <% end -%>
-  <% end -%>
-<% end -%>
+<%# Sanitize the compiled Mash to standard Array/Hash objects by way of JSON -%>
+<%= JSON.parse(({ 'instances' => @instances }).to_json).to_yaml %>
 
 init_config:
 # Nothing to configure here

test/integration/dd-agent-jmx/serverspec/Gemfile

@@ -0,0 +1,3 @@
+source 'https://rubygems.org'
+
+gem 'json_spec', '~> 1.1'

test/integration/dd-agent-jmx/serverspec/dd-agent-jmx_spec.rb

@@ -0,0 +1,61 @@
+# Encoding: utf-8
+require 'json_spec'
+require 'serverspec'
+require 'yaml'
+
+set :backend, :exec
+set :path, '/sbin:/usr/local/sbin:$PATH'
+
+JMX_CONFIG = '/etc/dd-agent/conf.d/jmx.yaml'
+
+describe service('datadog-agent') do
+  it { should be_running }
+end
+
+describe file(JMX_CONFIG) do
+  it { should be_a_file }
+
+  it 'is valid yaml matching input values' do
+    generated = YAML.load_file(JMX_CONFIG)
+
+    expected = {
+      'init_config' => nil,
+      'instances' => [
+        {
+          'conf' => [
+            {
+              'exclude' => [
+                {
+                  'domain' => 'evil_domain'
+                }
+              ],
+              'include' => {
+                'attribute' => {
+                  'bytesReceived' => { 'metric_type' => 'counter', 'alias' => 'tomcat.bytes_rcvd' },
+                  'maxThreads' => { 'metric_type' => 'gauge', 'alias' => 'tomcat.threads.max' }
+                },
+                'bean' => 'tomcat_bean',
+                'domain' => 'domain0',
+                'type' => 'ThreadPool'
+              },
+              'include' => {
+                'attributes' => [
+                  'BloomFilterDiskSpaceUsed',
+                  'Capacity'
+                ],
+                'bean_name' => 'com.datadoghq.test:type=BeanType,tag1=my_bean_name',
+                'domain' => 'org.apache.cassandra.db',
+                'foo' => 'bar'
+              }
+            }
+          ],
+          'extra_key' => 'extra_val',
+          'host' => 'localhost',
+          'port' => 9999
+        }
+      ]
+    }
+
+    expect(generated.to_json).to be_json_eql expected.to_json
+  end
+end