Change to AppDynamics tier_name resolution

This commit sets the `default_application_name` and `default_tier_name` to empty properties in the AppDynamics config file. This mean they can be easily set by an environment variable. If they are left empty and no value is given by the credentials payload of the bound AppDynamics service, then `application_name` already uses to the application name set by Cloud Foundry but the `tier_name` will now also use the application name set by Cloud Foundry for its value.

[#102469346]

Author: Christopher Frost

config/app_dynamics_agent.yml

@@ -17,5 +17,6 @@
 ---
 version: 4.1.+
 repository_root: ! '{default.repository.root}/app-dynamics'
+default_application_name:
 default_node_name: ! '$(expr "$VCAP_APPLICATION" : ''.*instance_index[": ]*\([[:digit:]]*\).*'')'
-default_tier_name: CloudFoundry
+default_tier_name:

docs/framework-app_dynamics_agent.md

@@ -13,7 +13,7 @@ The AppDynamics Agent Framework causes an application to be automatically config
 Tags are printed to standard output by the buildpack detect script
 
 ## User-Provided Service
-When binding AppDynamics using a user-provided service, it must have name or tag with `app-dynamics` or `appdynamics` in it.  The credential payload can contain the following entries:
+When binding AppDynamics using a user-provided service, it must have name or tag with `app-dynamics` or `appdynamics` in it. The credential payload can contain the following entries:
 
 | Name | Description
 | ---- | -----------
@@ -31,18 +31,18 @@ To provide more complex values such as the `tier-name`, using the interactive mo
 ## Configuration
 For general information on configuring the buildpack, refer to [Configuration and Extension][].
 
-The framework can be configured by modifying the [`config/app_dynamics_agent.yml`][] file in the buildpack fork.  The framework uses the [`Repository` utility support][repositories] and so it supports the [version syntax][] defined there.
+The framework can be configured by modifying the [`config/app_dynamics_agent.yml`][] file in the buildpack fork. The framework uses the [`Repository` utility support][repositories] and so it supports the [version syntax][] defined there.
 
 | Name | Description
 | ---- | -----------
-| `default_application_name` | This is not provided by default but can be added to specify the application name in the AppDynamics dashboard.  This can be overridden with an `application-name` entry in the credentials payload.
-| `default_tier_name` | The default tier name for this application in the AppDynamics dashboard.  This can be overridden with a `tier-name` entry in the credentials payload.
-| `default_node_name` | The default node name for this application in the AppDynamics dashboard.  The default value is an expression that will be evaluated based on the `instance_index` of the application. This can be overridden with a `node-name` entry in the credentials payload.
+| `default_application_name` | This is omitted by default but can be added to specify the application name in the AppDynamics dashboard. This can be overridden by an `application-name` entry in the credentials payload. If neither are supplied the default is the `application_name` as specified by Cloud Foundry.
+| `default_node_name` | The default node name for this application in the AppDynamics dashboard. The default value is an expression that will be evaluated based on the `instance_index` of the application. This can be overridden by a `node-name` entry in the credentials payload.
+| `default_tier_name` | This is omitted by default but can be added to specify the tier name for this application in the AppDynamics dashboard. This can be overridden by a `tier-name` entry in the credentials payload. If neither are supplied the default is the `application_name` as specified by Cloud Foundry.
 | `repository_root` | The URL of the AppDynamics repository index ([details][repositories]).
 | `version` | The version of AppDynamics to use. Candidate versions can be found in [this listing][].
 
 ### Additional Resources
-The framework can also be configured by overlaying a set of resources on the default distribution.  To do this, add files to the `resources/app_dynamics_agent` directory in the buildpack fork.  For example, to override the default `app-agent-config.xml` add your custom file to `resources/app_dynamics_agent/conf/app-agent-config.xml`.
+The framework can also be configured by overlaying a set of resources on the default distribution. To do this, add files to the `resources/app_dynamics_agent` directory in the buildpack fork. For example, to override the default `app-agent-config.xml` add your custom file to `resources/app_dynamics_agent/conf/app-agent-config.xml`.
 
 [`config/app_dynamics_agent.yml`]: ../config/app_dynamics_agent.yml
 [AppDynamics Service]: http://www.appdynamics.com

lib/java_buildpack/framework/app_dynamics_agent.rb

@@ -97,7 +97,8 @@ def ssl_enabled(java_opts, credentials)
       end
 
       def tier_name(java_opts, credentials)
-        name = credentials['tier-name'] || @configuration['default_tier_name']
+        name = credentials['tier-name'] || @configuration['default_tier_name'] ||
+          @application.details['application_name']
         java_opts.add_system_property('appdynamics.agent.tierName', "#{name}")
       end
 

spec/java_buildpack/framework/app_dynamics_agent_spec.rb

@@ -22,8 +22,9 @@
   include_context 'component_helper'
 
   let(:configuration) do
-    { 'default_tier_name' => 'test-tier-name',
-      'default_node_name' => "$(expr \"$VCAP_APPLICATION\" : '.*instance_index[\": ]*\\([[:digit:]]*\\).*')" }
+    { 'default_tier_name'        => nil,
+      'default_node_name'        => "$(expr \"$VCAP_APPLICATION\" : '.*instance_index[\": ]*\\([[:digit:]]*\\).*')",
+      'default_application_name' => nil }
   end
 
   it 'does not detect without app-dynamics-n/a service' do
@@ -65,7 +66,7 @@
         expect(java_opts).to include('-javaagent:$PWD/.java-buildpack/app_dynamics_agent/javaagent.jar')
         expect(java_opts).to include('-Dappdynamics.controller.hostName=test-host-name')
         expect(java_opts).to include('-Dappdynamics.agent.applicationName=test-application-name')
-        expect(java_opts).to include('-Dappdynamics.agent.tierName=test-tier-name')
+        expect(java_opts).to include('-Dappdynamics.agent.tierName=test-application-name')
         expect(java_opts).to include('-Dappdynamics.agent.nodeName=$(expr "$VCAP_APPLICATION" : ' \
                                      '\'.*instance_index[": ]*\\([[:digit:]]*\\).*\')')
       end