Support of environment variables in properties

Change-Id: I5028ad3b4fb63a96607915e8b424dd2e57696bf0
Issue-ID: POLICY-1514
Signed-off-by: Jorge Hernandez <jorge.hernandez-herrero@att.com>

3 files changed, 33 insertions, 6 deletions

diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java
index c0014f4d..3891c858 100644
--- a/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * policy-utils
  * ================================================================================
- * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2019 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
 
+import org.apache.commons.configuration2.ConfigurationConverter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,8 +51,10 @@ public class PropertyUtil {
     private static final Logger logger = LoggerFactory.getLogger(PropertyUtil.class.getName());
 
     /**
-     * Read in a properties file.
-     * 
+     * Read in a properties file.  Variable interpolation is performed by using
+     * apache commons configuration2 library.   This allows for embedding system properties,
+     * constants, and environment variables in property files.
+     *
      * @param file the properties file
      * @return a Properties object, containing the associated properties
      * @throws IOException - subclass 'FileNotFoundException' if the file
@@ -60,14 +63,21 @@ public class PropertyUtil {
      */
     public static Properties getProperties(File file) throws IOException {
         // create an InputStream (may throw a FileNotFoundException)
+        Properties rval = new Properties();
         try (FileInputStream fis = new FileInputStream(file)) {
             // create the properties instance
-            Properties rval = new Properties();
 
             // load properties (may throw an IOException)
             rval.load(fis);
-            return rval;
         }
+
+        /*
+         * Return properties file with environment variables interpolated.
+         * It is necessary to construct the object in this fashion and avoid
+         * builders since they use the commons-beanutils (optional) library that has been
+         * flagged as insecured.
+         */
+        return ConfigurationConverter.getProperties(ConfigurationConverter.getConfiguration(rval));
     }
 
     /**
diff --git a/policy-utils/src/test/java/org/onap/policy/drools/utils/PropertyUtilTest.java b/policy-utils/src/test/java/org/onap/policy/drools/utils/PropertyUtilTest.java
index 05440c69..2d5d356c 100644
--- a/policy-utils/src/test/java/org/onap/policy/drools/utils/PropertyUtilTest.java
+++ b/policy-utils/src/test/java/org/onap/policy/drools/utils/PropertyUtilTest.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * policy-utils
  * ================================================================================
- * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2019 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,11 +34,18 @@ import java.util.UUID;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import org.onap.policy.drools.utils.logging.LoggerUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class PropertyUtilTest {
+
     private static final Logger logger = LoggerFactory.getLogger(PropertyUtilTest.class);
+    private static final String INTERPOLATION_PROPERTIES = "src/test/resources/interpolation.properties";
+    private static final String INTERPOLATION_NO = "interpolation.no";
+    private static final String INTERPOLATION_ENV = "interpolation.env";
+    private static final String INTERPOLATION_CONST = "interpolation.const";
+    private static final String INTERPOLATION_SYS = "interpolation.sys";
 
     private static File directory = null;
 
@@ -128,6 +135,12 @@ public class PropertyUtilTest {
 
         // they should match
         assertEquals(prop1, prop2);
+
+        Properties prop3 = PropertyUtil.getProperties(INTERPOLATION_PROPERTIES);
+        assertEquals("no", prop3.getProperty(INTERPOLATION_NO));
+        assertEquals(System.getenv("HOME"), prop3.getProperty(INTERPOLATION_ENV));
+        assertEquals(LoggerUtil.ROOT_LOGGER, prop3.getProperty(INTERPOLATION_CONST));
+        assertEquals(System.getProperty("user.home"), prop3.getProperty(INTERPOLATION_SYS));
     }
 
     /**
diff --git a/policy-utils/src/test/resources/interpolation.properties b/policy-utils/src/test/resources/interpolation.properties
new file mode 100644
index 00000000..66554337
--- /dev/null
+++ b/policy-utils/src/test/resources/interpolation.properties
@@ -0,0 +1,4 @@
+interpolation.no=no
+interpolation.env=${env:HOME}
+interpolation.const=${const:org.onap.policy.drools.utils.logging.LoggerUtil.ROOT_LOGGER}
+interpolation.sys=${sys:user.home}