Is there a way to dynamically load a properties file in NAnt?

Question

I want to load a different properties file based upon one variable.

Basically, if doing a dev build use this properties file, if doing a test build use this other properties file, and if doing a production build use yet a third properties file.

Answer 1

Step 1: Define a property in your NAnt script to track the environment you're building for (local, test, production, etc.).

<property name="environment" value="local" />

Step 2: If you don't already have a configuration or initialization target that all targets depends on, then create a configuration target, and make sure your other targets depend on it.

<target name="config">
    <!-- configuration logic goes here -->
</target>

<target name="buildmyproject" depends="config">
    <!-- this target builds your project, but runs the config target first -->
</target>

Step 3: Update your configuration target to pull in an appropriate properties file based on the environment property.

<target name="config">
    <property name="configFile" value="${environment}.config.xml" />
    <if test="${file::exists(configFile)}">
        <echo message="Loading ${configFile}..." />
        <include buildfile="${configFile}" />
    </if>
    <if test="${not file::exists(configFile) and environment != 'local'}">
        <fail message="Configuration file '${configFile}' could not be found." />
    </if>
</target>

Note, I like to allow team members to define their own local.config.xml files that don't get committed to source control. This provides a nice place to store local connection strings or other local environment settings.

Step 4: Set the environment property when you invoke NAnt, e.g.:

• nant -D:environment=dev
• nant -D:environment=test
• nant -D:environment=production

Answer 2

You can use the include task to include another build file (containing your properties) within the main build file. The if attribute of the include task can test against a variable to determine whether the build file should be included:

<include buildfile="devPropertyFile.build" if="${buildEnvironment == 'DEV'}"/>
<include buildfile="testPropertyFile.build" if="${buildEnvironment == 'TEST'}"/>
<include buildfile="prodPropertyFile.build" if="${buildEnvironment == 'PROD'}"/>

Answer 3

I had a similar problem which the answer from scott.caligan partially solved, however I wanted people to be able to set the environment and load the appropriate properties file just by specifying a target like so:

• nant dev
• nant test
• nant stage

You can do this by adding a target that sets the environment variable. For instance:

<target name="dev">
  <property name="environment" value="dev"/>
  <call target="importProperties" cascade="false"/>
</target>

<target name="test">
  <property name="environment" value="test"/>
  <call target="importProperties" cascade="false"/>
</target>

<target name="stage">
  <property name="environment" value="stage"/>
  <call target="importProperties" cascade="false"/>
</target>

<target name="importProperties">
  <property name="propertiesFile" value="properties.${environment}.build"/>
  <if test="${file::exists(propertiesFile)}">
    <include buildfile="${propertiesFile}"/>
  </if>
  <if test="${not file::exists(propertiesFile)}">
    <fail message="Properties file ${propertiesFile} could not be found."/>
  </if>
</target>