GetVersions.java

package org.epics.archiverappliance.mgmt.bpl;

import java.io.IOException;
import java.io.PrintWriter;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.epics.archiverappliance.common.BPLAction;
import org.epics.archiverappliance.config.ApplianceInfo;
import org.epics.archiverappliance.config.ConfigService;
import org.epics.archiverappliance.utils.ui.GetUrlContent;
import org.epics.archiverappliance.utils.ui.MimeTypeConstants;
import org.json.simple.JSONObject;

/**
 * 
 * @epics.BPLAction - Get the versions of the various components for this appliance. 
 * @epics.BPLActionParam id - The identity of the appliance for which we are requesting information. This is the same string as the <code>identity</code> element in the <code>appliances.xml</code> that identifies this appliance.
 * @epics.BPLActionEnd
 * 
 * @author mshankar
 *
 */
public class GetVersions implements BPLAction {
	private static Logger logger = Logger.getLogger(GetVersions.class.getName());
	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp, ConfigService configService) throws IOException {
		String id = req.getParameter("id");
		ApplianceInfo applianceInfo = null;
		if(id == null || id.equals("")) {
			applianceInfo = configService.getMyApplianceInfo();
			logger.debug("No id specified, returning the id of this appliance " + applianceInfo.getIdentity());
		} else {
			logger.debug("Getting Appliance info for appliance with identity " + id);
			applianceInfo = configService.getAppliance(id);			
		}
		
		if(applianceInfo == null) {
			logger.warn("Cannot find appliance info for " + id);
			resp.sendError(HttpServletResponse.SC_NOT_FOUND);
			return;
		}

		resp.setContentType(MimeTypeConstants.APPLICATION_JSON);
		try (PrintWriter out = resp.getWriter()) {
			HashMap<String, String> versions = new HashMap<String, String>();
			Path versionPath = Paths.get(req.getServletContext().getRealPath("ui/comm/version.txt"));
			String mgmt_version = Files.readAllLines(versionPath, Charset.defaultCharset()).get(0);
			versions.put("mgmt_version", mgmt_version);
			getVersion(applianceInfo.getEngineURL(), "engine", versions, mgmt_version);
			getVersion(applianceInfo.getEtlURL(), "etl", versions, mgmt_version);
			getVersion(applianceInfo.getRetrievalURL(), "retrieval", versions, mgmt_version);			
			out.println(JSONObject.toJSONString(versions));
		} catch(Exception ex) {
			logger.error("Exception marshalling typeinfo for appliance " + id, ex);
			resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		}
	}
	
	private void getVersion(String URL, String prefix, HashMap<String, String> versions, String mgmt_version) { 
		String finalURL = URL + "/getVersion";
		JSONObject componentVersion = GetUrlContent.getURLContentAsJSONObject(finalURL);
		String versionFromComponent = (String) componentVersion.get("version");
		versions.put(prefix + "_version", versionFromComponent);
		if(!mgmt_version.equals(versionFromComponent)) { 
			versions.put("components_with_different_versions", "true");
		}
	}
}