web - externalize the configuration of dsmiley's proxy servlets

docker/config/geonetwork/geonetwork.properties

@@ -0,0 +1,5 @@
+# TODO: still in a WIP state, to be merged with config-geonetwork-georchestra.properties from the classpath
+
+es.featureproxy.targeturi=http://localhost:9200/gn-features/{_}
+kb.url=http://kibana:5601
+

web/src/main/java/org/fao/geonet/proxy/ConfigurableProxyServlet.java

@@ -0,0 +1,21 @@
+package org.fao.geonet.proxy;
+
+import org.apache.http.client.utils.URIUtils;
+
+import javax.servlet.ServletException;
+import java.net.URI;
+
+public class ConfigurableProxyServlet extends org.mitre.dsmiley.httpproxy.ProxyServlet {
+    @Override
+    protected void initTarget() throws ServletException {
+        String propName = getConfigParam(P_TARGET_URI);
+        targetUri = GeorchestraPropertyResolver.resolveProperty(propName);
+        // checks this is a valid uri
+        try {
+            targetUriObj = new URI(targetUri);
+        } catch (Exception e) {
+            throw new ServletException("Trying to process targetUri init parameter: "+e,e);
+        }
+        targetHost = URIUtils.extractHost(targetUriObj);
+    }
+}

web/src/main/java/org/fao/geonet/proxy/ConfigurableUriTemplateProxyServlet.java

@@ -0,0 +1,11 @@
+package org.fao.geonet.proxy;
+
+import javax.servlet.ServletException;
+
+public class ConfigurableUriTemplateProxyServlet extends org.mitre.dsmiley.httpproxy.URITemplateProxyServlet {
+    @Override
+    protected void initTarget() throws ServletException {
+        String propName = getConfigParam(P_TARGET_URI);
+        targetUriTemplate = GeorchestraPropertyResolver.resolveProperty(propName);
+    }
+}

web/src/main/java/org/fao/geonet/proxy/GeorchestraPropertyResolver.java

@@ -0,0 +1,36 @@
+package org.fao.geonet.proxy;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.nio.file.Paths;
+import java.util.Properties;
+
+/**
+ * This class allows to resolve variables from the georchestra.datadir/geonetwork/geonetwork.properties
+ * file at runtime.
+ *
+ * Using servlets from dsmiley.httproxy group does not allow to easily configure them outside of
+ * the web.xml. This class provides a static method to do so, which is called from the 2 other
+ * classes from the package which extend the ones from dsmiley's package.
+ *
+ * @see {org.fao.geonet.ConfigurableProxyServlet} and {org.fao.geonet.ConfigurableUriTemplateProxyServlet}.
+ */
+public class GeorchestraPropertyResolver {
+
+    public static String resolveProperty(String name) {
+        File props = Paths.get(System.getProperty("georchestra.datadir"),
+            "geonetwork", "geonetwork.properties").toFile();
+        if (! props.exists() || ! props.canRead()) {
+            throw new RuntimeException("unable to load geonetwork.properties from the geOrchestra datadir");
+        }
+        Properties gnProps = new Properties();
+
+        try(InputStream fis = new FileInputStream(props)) {
+            gnProps.load(fis);
+        } catch (Exception ex) {
+            throw new RuntimeException("unable to read geonetwork.properties from the geOrchestra datadir");
+        }
+        return gnProps.getProperty(name);
+    }
+}

web/src/main/webResources/WEB-INF/web.xml

@@ -405,10 +405,10 @@
   -->
   <servlet>
     <servlet-name>ESFeaturesProxy</servlet-name>
-    <servlet-class>org.mitre.dsmiley.httpproxy.URITemplateProxyServlet</servlet-class>
+    <servlet-class>org.fao.geonet.proxy.ConfigurableUriTemplateProxyServlet</servlet-class>
     <init-param>
       <param-name>targetUri</param-name>
-      <param-value>${es.url}/${es.index.features}/{_}</param-value>
+      <param-value>es.featureproxy.targeturi</param-value>
     </init-param>
     <init-param>
       <param-name>log</param-name>
@@ -422,10 +422,10 @@
 
   <servlet>
     <servlet-name>HttpDashboardProxy</servlet-name>
-    <servlet-class>org.mitre.dsmiley.httpproxy.ProxyServlet</servlet-class>
+    <servlet-class>org.fao.geonet.proxy.ConfigurableProxyServlet</servlet-class>
     <init-param>
       <param-name>targetUri</param-name>
-      <param-value>${kb.url}</param-value>
+      <param-value>kb.url</param-value>
     </init-param>
     <init-param>
       <param-name>log</param-name>