Friday, 19 August 2016

Variable substitution for a manifest.yml for Cloud Foundry

Pushed applications to CF or PCF you would of most likely used a manifest.yml file and at some point wanted to use variable substitution. manifest.yml files don't support that and a feature request has been asked for this as follows

https://github.com/cloudfoundry/cli/issues/820

With a recent customer we scripted the creation of a manifest.yml file from a Jenkins job  which would inject the required ROUTE to the application by creating the manifest.yml through a script as follows as shown below.

manifest-demo.sh

export ROUTE=$1

echo ""
echo "Setting route to $ROUTE ..."
echo ""

cat > manifest.yml <<!
---
applications:
- name: gs-rest-service
  memory: 256M
  instances: 1
  host: $ROUTE
  path: target/gs-rest-service-0.1.0.jar
!

cat manifest.yml

Script tested as follows

pasapicella@pas-macbook:~/bin/manifest-demo$ ./manifest-demo.sh apples-route-pas

Setting route to apples-route-pas ...

---
applications:
- name: gs-rest-service
  memory: 256M
  instances: 1
  host: apples-route-pas
  path: target/gs-rest-service-0.1.0.jar

Tuesday, 16 August 2016

HttpSessionListener with Spring Boot Application

I had a requirement to implement a HttpSessionListener in my Spring Boot application which has no web.xml. To achieve this I did the following

1. My HttpSessionListener was defined as follows

 
package com.pivotal.pcf.mysqlweb.utils;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import org.apache.log4j.Logger;

public class SessionListener implements HttpSessionListener
{
    protected static Logger logger = Logger.getLogger("controller");
    private HttpSession session = null;

    public void sessionCreated(HttpSessionEvent event)
    {
        // no need to do anything here as connection may not have been established yet
        session  = event.getSession();
        logger.info("Session created for id " + session.getId());
    }

    public void sessionDestroyed(HttpSessionEvent event)
    {
        session  = event.getSession();
     /*
      * Need to ensure Connection is closed from ConnectionManager
      */

        ConnectionManager cm = null;

        try
        {
            cm = ConnectionManager.getInstance();
            cm.removeConnection(session.getId());
            logger.info("Session destroyed for id " + session.getId());
        }
        catch (Exception e)
        {
            logger.info("SesssionListener.sessionDestroyed Unable to obtain Connection", e);
        }
    }
}

2. Register the listener from a @Configration class as shown below
  
package com.pivotal.pcf.mysqlweb;

import com.pivotal.pcf.mysqlweb.utils.SessionListener;
import org.springframework.boot.context.embedded.ServletListenerRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.http.HttpSessionListener;

@Configuration
public class ApplicationSessionConfiguration
{
    @Bean
    public ServletListenerRegistrationBean<HttpSessionListener> sessionListener()
    {
        return new ServletListenerRegistrationBean<HttpSessionListener>(new SessionListener());
    }
} 
Thats all you have to do to achieve this


Friday, 12 August 2016

Simple Spring Boot Application Deployed through Concourse UI to Pivotal Cloud Foundry

The demo below is a full working example of using Spring Boot Application which will build/deploy to Pivotal Cloud Foundry using Concourse. Concourse pipelines can easily be created within your source code as this demo shows and hence created / executed quite easily. Concourse limits itself to three core concepts: tasks, resources, and the jobs that compose them.

https://github.com/papicella/SpringBootSimpleRest

Detailed instructions on how to setup/run this demo using Concourse see the link referenced above which is as follows

https://dl.dropboxusercontent.com/u/15829935/platform-demos/concourse-demo/index.html



It's worth reading the details on this link around Concourse Concepts

https://concourse.ci/concepts.html

More Information

https://concourse.ci/