Custom Deployer Extension in SDL WEB 8.5 - Purge Cache Part - 2

In the previous post, we set up the custom deployer project, discussed its requirement and the use of deployer extension. Today, we are going to continue to use that same project and implement a real-life use-case.

Background:- In our current project we are using SDL WEB 8.5 and .NET DXA 1.8 and to improve the performance of the web application we implemented the custom caching with cache expires after 15 mins, but the business team has this requirement that they want to see the content "Real-time", no delay whenever the publish any new content.

Based on their requirement we came up with this approach and decided to write a custom deployer extension. So, whenever the author publish the page(s), the deployer extension will trigger and clear the cache of that particular page based on the URL extracted from PageMetaData.

In the below code snippet we are reading the page relative URL retrieved from PageMetaData and with the help of string manipulation we've created the absolute URL and based on the Query String parameter we trigger the code to purge the cache. Check the HTTP response code it should be 200 in the logs and refresh the web page to check the latest content.

 // This is called once for each Transport Package that is deployed.  
      @Override  
      public void process(TransportPackage data) throws ProcessingException   
      {  
            log.debug("This is custom logs");  
            String USER_AGENT = "Mozilla/5.0";  
            log.debug("PublicationId : " + String.valueOf(data.getProcessorInstructions().getPublicationId().getItemId()));  
           try  
           {  
            log.debug("Custom Code :- Entered in the try block");  
            PageMetaData pageFile = (PageMetaData)data.getMetaDataFile("Pages");  
            log.debug("Custom code :- Reading PageMetaData");  
            if (pageFile != null)  
      {  
        List<Page> pages = pageFile.getPages();  
        for ( Page page : pages )  
        {  
             log.debug("Custom code :- For loop to get the page url ");  
             log.debug("http://localhost:92"+page.getURLPath()+"?ClearCache=true");   
             String URL = "http://localhost:92"+page.getURLPath()+"?ClearCache=true";  
             URL obj = new URL(URL);  
             HttpURLConnection con = (HttpURLConnection) obj.openConnection();  
             con.setConnectTimeout(5000);  
             log.debug("Custom code :- timeout");  
             con.setRequestMethod("GET");  
             con.setRequestProperty("User-Agent", USER_AGENT);  
             int responseCode = con.getResponseCode();  
             log.debug("Response Code : " + responseCode);  
             if (responseCode == HttpURLConnection.HTTP_OK)  
             {  
              log.debug("Custom Deployer, Cache has been removed and the responseCode is : " + responseCode + "- for URL " + URL);  
             }  
             log.debug("Page ID :" + String.valueOf(page.getId().getItemId()));  
        }  
      }  
            log.debug("Purging is done !! Please check the web page!!");  
           }  
           catch (Exception e)  
     {  
        log.error("Could not get path for publication.", e);  
        return;  
     }  
  }  

Logs generated by the deployer.

Deployer Logs

With the help of the deployer extension, we were able to achieve and deliver the real-time experience and still managing the performance of the site using cache.


Happy Coding and Keep Sharing !!!

Custom Deployer Extension in SDL WEB 8.5 Part - 1

Today, we are going to see how to extend the default SDL Tridion deployment functionality, using Custom Deployer Extension. Before we move forward and start building/set up the project let's first understand the use of Deployer Extension. When a user publishes content, the Content Deployer unpacks the incoming Transport Package and processes its transport instructions and we can extend the default behavior of the Content Deployer by creating a custom Module and adding it to a Step, or by extending an existing Module.

Deployer Extension:- 

• Deployer Extension is used to inject additional functionality in the default SDL Tridion deployment process. 
• If you want to implement your custom logic/data. "Event System might be useful here as well 🤔 We need to be absolutely sure about it".
• If you want to use some specific data/info which is only available at the time of deployment.   
• Based on JAVA.
• You can extend the default behavior of the Content Deployer by creating a custom Module and adding it to a Step, or by extending an existing Module.

In order to set up the JAVA project for the Deployer Extension, I have used Eclipse IDE, default JARs provided by SDL and JAVA 8. 

First, we need to configure the JAVA project using Eclipse.

1. Click on File --> New --> Other Project and then select Java Project and click Next.

Create New JAVA Project

2. Enter the Project Name

Enter the Project Name.

3. Create a new folder called "lib" which will contain all the JARs.

Create new Folder lib

4. Copy all the JARs in lib, you can find all the default JAR files in the deployer microservice lib folder. Once copied then we need to Add the Build PATH.

Add JARs Build Path

5 Next, is create a Java package and then create a CLASS file.

Create a new Java Package

Create a New Class

6. Start Importing all the Namespace that's required in order to extend the deployer.

Tridion Default Namespaces.

7. Next is we must implement the abstract method  Module.process(TransportPackage)

 package com.tridion.deployer.extension;  
 import org.slf4j.Logger;  
 import org.slf4j.LoggerFactory;  
 import com.tridion.configuration.Configuration;  
 import com.tridion.configuration.ConfigurationException;  
 import com.tridion.deployer.Module;  
 import com.tridion.deployer.ProcessingException;  
 import com.tridion.deployer.Processor;  
 import com.tridion.transport.transportpackage.TransportPackage;  
 public class PurgeCache extends Module {  
      protected static Logger log = LoggerFactory.getLogger(PurgeCache.class);  
        
      public PurgeCache(Configuration config, Processor processor) throws ConfigurationException  
      {  
           super(config,processor);  
      }  
      // This is called once for each Transport Package that is deployed.  
      @Override  
      public void process(TransportPackage data) throws ProcessingException   
      {  
            log.debug("This is custom logs");  
            int publicationId =data.getProcessorInstructions().getPublicationId().getItemId();  
            log.debug("PublicationId : " + String.valueOf(publicationId));  
      }  
 }  

That's it Export this into a JAR and next is the configuration in the deployer_config.xml of Deployer Microservice. "Don't forget to restart the service".

Click Export

Click Jar file and then Next

Custom Deployer Extension JAR file is ready

Finally, we need to deploy the custom JAR in the deployer microservice lib folder and open the deployer_config.xml file in your favorite editor add the below configuration, save the file Don't forget to take a backup before you start editing.

 <Step Factory="com.sdl.delivery.deployer.steps.TridionExecutableStepFactory" Id="PurgeCacheSteps">  
   <Module Type="PurgeCache" Class="com.tridion.deployer.extension.PurgeCache">  
   </Module>  
 </Step>  

 We also need to edit the logback.xml

 <logger name="com.tridion.deployer.extension">  
     <appender-ref ref="rollingDeployerLog"/>  
 </logger>  

Let's do some publishing and see if everything is working fine. Ideally, we should be able to see the logs entries. If you see the custom logs in the log file that means your custom code is interesting with default deployment process and you've built the extension successfully.

Log File

In the next blog, we will use the deployer extension with a very interesting use-case, until then.

Happy Coding and Keep Sharing !!!