Merge pull request #170 from LinuxForHealth/620-config-home-env

620 config home env - allow using environment variable to set config.properties home

README.md

@@ -93,11 +93,16 @@ The converter configuration file, config.properties, supports the following sett
 | default.zoneid          | ISO 8601 timezone offset (optional). The zoneid is applied to translations when the target FHIR resource field requires a timezone, but the source HL7 field does not include it. | +08:00                          |
 | additional.conceptmap   | Path to additional concept map configuration. Concept maps are used for mapping one code system to another.                                                                       | /opt/converter/concept-map.yaml |
 
-The config.properties file location is set using the System property, `config.home`
+### HL7 Converter Configuration Property Location
 
-```
--Dconfig.home=/opt/converter/config
-```
+The config.properties file location is searched in the following order:
+
+* HL7CONVERTER_CONFIG_HOME environment variable is checked first
+* hl7converter.config.home system property is checked next 
+
+   ``` -Dhl7converter.config.home=/opt/converter/config_home_folder/```
+
+* Lastly, the local classpath resource folder will be searched for config.properties
 
 ## Additional Documentation
 * [Templating Configuration](./TEMPLATING.md)

src/main/java/io/github/linuxforhealth/core/config/ConfigDirectoryLocationStrategy.java

@@ -17,7 +17,9 @@
 
 public class ConfigDirectoryLocationStrategy implements FileLocationStrategy {
 
-  private static final String CONF_PROP_HOME = "config.home";
+  private static final String CONF_PROP_HOME_SYSTEM_PROP = "hl7converter.config.home";
+  private static final String CONF_PROP_HOME_ENV_VAR = "HL7CONVERTER_CONFIG_HOME";
+
   private static final Logger LOGGER =
       LoggerFactory.getLogger(ConfigDirectoryLocationStrategy.class);
 
@@ -65,6 +67,9 @@ public URL locate(final FileSystem fileSystem, final FileLocator locator) {
 
 
   private static String fetchHomeDirectory() {
-    return System.getProperty(CONF_PROP_HOME);
+	String homeDirectory = System.getenv(CONF_PROP_HOME_ENV_VAR);
+	if (homeDirectory==null || homeDirectory.trim().isEmpty())
+		return System.getProperty(CONF_PROP_HOME_SYSTEM_PROP);
+	return homeDirectory;
   }
 }

src/test/java/io/github/linuxforhealth/core/config/ConverterConfigurationTest.java

@@ -13,7 +13,9 @@
 import java.io.IOException;
 import java.util.Properties;
 
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -22,21 +24,40 @@
 
 public class ConverterConfigurationTest {
 
-    @TempDir
+
+	private static final String CONF_PROP_HOME = "hl7converter.config.home";
+
+	@TempDir
     static File folder;
+
+    static String originalConfigHome;
+
+    @BeforeAll
+    public static void saveConfigHomeProperty() {
+    	originalConfigHome = System.getProperty(CONF_PROP_HOME);
+    }
 
     @AfterEach
     public void reset() {
-        System.clearProperty("config.home");
+        System.clearProperty(CONF_PROP_HOME);
         ConverterConfiguration.reset();
         UrlLookup.reset();
     }
+    @AfterAll
+    public static void reloadPreviousConfigurations() {
+    	if (originalConfigHome != null)
+    		System.setProperty(CONF_PROP_HOME, originalConfigHome);
+    	else
+    		System.clearProperty(CONF_PROP_HOME);
+        UrlLookup.reset();
+    }
+
 
     @Test
     public void test_that_additional_conceptmap_values_are_loaded() throws IOException {
     	File configFile = new File(folder, "config.properties");
         writeProperties(configFile);
-        System.setProperty("config.home", configFile.getParent());
+        System.setProperty(CONF_PROP_HOME, configFile.getParent());
         ConverterConfiguration.reset();
         UrlLookup.reset(Constants.CODING_SYSTEM_MAPPING);
         String url = UrlLookup.getSystemUrl("LN");