GeoServerNodeData.java

/* (c) 2017 Open Source Geospatial Foundation - all rights reserved
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver;

import org.geoserver.ows.util.KvpUtils;
import org.geoserver.platform.GeoServerExtensions;
import org.geotools.util.logging.Logging;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Holds information about how to identify a geoserver node within a cluster.
 * <p>
 *   Contains both the node identifier itself, and information about how to style the id
 *   for UI purposes.
 * </p>
 */
public class GeoServerNodeData {

  /**
   * System property, environment variable, etc... used to specify the node id. 
   */
  public static final String GEOSERVER_NODE_OPTS = "GEOSERVER_NODE_OPTS";

  static final String DEFAULT_NODE_ID_TEMPLATE = "position:absolute; top:12px; left:12px; right:28px; width:auto; background:$background; padding: 1px; border: 1px solid #0076a1; color:$color; font-weight:bold";
  
  static final Logger LOGGER = Logging.getLogger(GeoServerNodeData.class);

  final String nodeId;
  final String nodeIdStyle;

  public GeoServerNodeData(String nodeId, String nodeIdStyle) {
    this.nodeId = nodeId;
    this.nodeIdStyle = nodeIdStyle;
  }

  /**
   * Creates a node data from a format-options style string.
   */
  public static GeoServerNodeData createFromString(String nodeOpts) {
    String nodeId = null;
    String nodeIdStyle = null;

    if (nodeOpts == null) {
      nodeId = null;
      nodeIdStyle = null;
    } else {
      try {
        Map<String, String> options = parseProperties(nodeOpts);
        String id = (String) options.get("id");
        if (id != null) {
          if (id.contains("$host_ip")) {
            InetAddress address = getLocalHostLANAddress();
            id = id.replace("$host_ip", address.getHostAddress());
          } else if (id.contains("$host_name")) {
            InetAddress address = getLocalHostLANAddress();
            id = id.replace("$host_name", address.getHostName());
          }
        }

        nodeId = id;
        String bgcolor = (String) options.get("background");
        if (bgcolor == null) {
          bgcolor = "#dadada";
        }
        String style = DEFAULT_NODE_ID_TEMPLATE.replace("$background", bgcolor);
        String color = (String) options.get("color");
        if (color == null) {
          color = "#0076a1";
        }
        nodeIdStyle = style.replace("$color", color);
      } catch (Exception e) {
        LOGGER.log(Level.SEVERE,
            "Failed to parse GEOSERVER_NODE_OPTS, expected syntax is id:<nodeid>;color:<css_color>, but got "
                + nodeOpts + " instead. Disabling NODE_ID GUI element");
        nodeId = null;
        nodeIdStyle = null;
      }
    }

    return new GeoServerNodeData(nodeId, nodeIdStyle);
  }

  /**
   * Creates the node data from environment variable, system property, etc... define by {@link #GEOSERVER_NODE_OPTS}
   */
  public static GeoServerNodeData createFromEnvironment() {
    return createFromString(GeoServerExtensions.getProperty(GEOSERVER_NODE_OPTS));
  }

  static InetAddress getLocalHostLANAddress() throws UnknownHostException {
    try {
      InetAddress candidateAddress = null;
      // Iterate all NICs (network interface cards)...
      for (Enumeration interfaces = NetworkInterface.getNetworkInterfaces(); interfaces
          .hasMoreElements();) {
        NetworkInterface ni = (NetworkInterface) interfaces.nextElement();
        // each interface can have more than one address
        for (Enumeration inetAddrs = ni.getInetAddresses(); inetAddrs.hasMoreElements();) {
          InetAddress inetAddr = (InetAddress) inetAddrs.nextElement();
          // we are not interested in loopback
          if (!inetAddr.isLoopbackAddress()) {
            if (inetAddr.isSiteLocalAddress()) {
              return inetAddr;
            } else if (candidateAddress == null) {
              candidateAddress = inetAddr;
            }
          }
        }
      }
      if (candidateAddress != null) {
        return candidateAddress;
      }
      // Fall back to whatever localhost provides
      InetAddress jdkSuppliedAddress = InetAddress.getLocalHost();
      if (jdkSuppliedAddress == null) {
        throw new UnknownHostException(
            "The JDK InetAddress.getLocalHost() method unexpectedly returned null.");
      }
      return jdkSuppliedAddress;
    } catch (Exception e) {
      UnknownHostException unknownHostException = new UnknownHostException(
          "Failed to determine LAN address");
      unknownHostException.initCause(e);
      throw unknownHostException;
    }
  }

  /**
   * Parses a format-options like paramter, ; separated, with : as the assignment operator,
   * key1:value1;key2=value2;..., using backslash as the escape char if needed
   */
  private static Map<String, String> parseProperties(String property) {
    Map<String, String> properties = new HashMap<String, String>();
    List<String> kvps = KvpUtils.escapedTokens(property, ';');

    for (String kvp : kvps) {
      List<String> kv = KvpUtils.escapedTokens(kvp, ':', 2);
      String key = kv.get(0).toLowerCase();
      String value = kv.size() == 1 ? "true" : KvpUtils.unescape(kv.get(1));
      properties.put(key, value);
    }

    return properties;
  }

  /**
   * The node id.
   */
  public String getId() {
    return nodeId;
  }

  /**
   * The node id styling.
   */
  public String getIdStyle() {
    return nodeIdStyle;
  }
}