Affected Issue(s): #606 (#612)

What this commit has achieved:
1. Externalized location of "mdm-rules.json" in the `AppProperties`
2. More info about the `ResourceLoader` interface is available at
https://docs.spring.io/spring-framework/reference/core/resources.html#resources-resourceloader

src/main/java/ca/uhn/fhir/jpa/starter/AppProperties.java

@@ -27,6 +27,7 @@ public class AppProperties {
   private Boolean ips_enabled = false;
   private Boolean openapi_enabled = false;
   private Boolean mdm_enabled = false;
+  private String mdm_rules_json_location = "mdm-rules.json";
   private boolean advanced_lucene_indexing = false;
   private boolean enable_index_of_type = false;
   private Boolean allow_cascading_deletes = false;
@@ -191,6 +192,14 @@ public class AppProperties {
     this.mdm_enabled = mdm_enabled;
   }
 
+  public String getMdm_rules_json_location() {
+	return mdm_rules_json_location;
+}
+
+public void setMdm_rules_json_location(String mdm_rules_json_location) {
+	this.mdm_rules_json_location = mdm_rules_json_location;
+}
+
 public Cors getCors() {
     return cors;
   }

src/main/java/ca/uhn/fhir/jpa/starter/mdm/MdmConfig.java

@@ -28,7 +28,7 @@ public class MdmConfig {
 	IMdmSettings mdmSettings(@Autowired MdmRuleValidator theMdmRuleValidator, AppProperties appProperties)
 			throws IOException {
 		DefaultResourceLoader resourceLoader = new DefaultResourceLoader();
-		Resource resource = resourceLoader.getResource("mdm-rules.json");
+		Resource resource = resourceLoader.getResource(appProperties.getMdm_rules_json_location());
 		String json = IOUtils.toString(resource.getInputStream(), StandardCharsets.UTF_8);
 		return new MdmSettings(theMdmRuleValidator)
 				.setEnabled(appProperties.getMdm_enabled())

src/main/resources/application.yaml

@@ -137,6 +137,7 @@ hapi:
     #    graphql_enabled: true
     narrative_enabled: false
     mdm_enabled: false
+    mdm_rules_json_location: "mdm-rules.json"
     #    local_base_urls:
     #      - https://hapi.fhir.org/baseR4
     #    partitioning: