Installing OpenStack on AWS

1. Prerequisites – Minimal requirements for hosting in AWS, but not limited to:

  • Ubuntu Server 14.04.3 LTS – 64bit
  • Minimum 2VCPU – Cores
  • Minimum 8 GB RAM for just OpenStack (m4.large), Minimum 16 GB RAM for Sahara and clustering (m4.xlarge)
  • Atleast 40 GB of diskspace

2. Install Ubuntu if you dont have one

3. Verify installed version using

lsb_release -d
free -m
df -h

4. Update to the latest binaries

sudo apt-get update

5. Create a SUDO user – alternatively you can use the /devstack/tools/create-stack-user.sh to create a user after step 8

sudo -i
adduser stack			
	Enter new UNIX password:
	Retype new UNIX password:
	passwd: password updated successfully
	Changing the user information for username
	Enter the new value, or press ENTER for the default
	Full Name []:stack
	Room Number []:
	Work Phone []:
	Home Phone []:
	Other []:
	Is the information correct? [Y/n] Y

6. Add user to SUDOERs group

usermod -aG sudo stack 
echo "stack ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers

7. Switch to the new stack user

su - stack
check if the user can do sudo operations without password prompts
sudo ls -la /root

8. Switch to user home and install GIT and checkout devstack

cd ~
sudo apt-get install git
git clone https://github.com/openstack-dev/devstack

9. Configure devstack – update local.config and move to /devstack

cd /devstack
cp sample/local.conf .

* Update the passwords for the accounts

ADMIN_PASSWORD=St@ckNewPwd1
DATABASE_PASSWORD=St@ckNewPwd1
RABBIT_PASSWORD=St@ckNewPwd1
SERVICE_PASSWORD=St@ckNewPwd1

* If you are running on a physical machine with a static IP you can update the following property. On AWS its better to leave it commented as the local IP will be changed on each restart, unless the Elastic IP is assigned to the instance

HOST_IP=172.31.26.172

* And add the following line at the end of the file. These entries will add the Sahara plugin (Data Processing) in OpenStack UI

echo "enable_plugin sahara git://github.com/openstack/sahara" >> local.conf
echo "enable_plugin sahara-dashboard git://github.com/openstack/sahara-dashboard" >> local.conf
echo "enable_plugin ceilometer git://github.com/openstack/ceilometer" >> local.conf

10. Start the stack services

./stack.sh

* This takes up sometime and logs will be available at /opt/stack/logs. On successful completion you will find details something similar as below.

=========================
DevStack Component Timing
=========================
Total runtime         1169
run_process            57
test_with_retry         3
apt-get-update          3
pip_install           299
restart_apache_server  10
wait_for_service       11
git_timed             244
apt-get                69
=========================

This is your host IP address: 172.31.26.172
This is your host IPv6 address: ::1
Horizon is now available at http://172.31.26.172/dashboard
Keystone is serving at http://172.31.26.172/identity/
The default users are: admin and demo
The password: St@ckNewPwd1
stack@ip-172-31-26-172:~/devstack$

11. To access the dashboard hit http://172.31.26.172/dashboard in browser (with the ip as displayed in the above step). If you are running in local PC you can directly access with the above url. But if you are running on AWS, this is the internal IP and will not be available to the outside world. In this case, allow HTTP access on 80 port for the outside world and access the service with the Public IP or DNS hostname allocated to your instance. This in my case http://54.23.123.43/dashboard.

Create Web Services using Axis Java2WSDL, WSDL2Java and Eclipse for all Servers manually – Part 2

With all the basic configurations done as specified in the last Article we continue to develop the Business logic.

  1. Create a class named Calculator.java, place four public methods add, subtract, multiply and delete and place the appropriate logics in it.
    package com.itechgenie.services.impl;
    public class Calculator {
    	public int add(int a, int b) {
    		return a+b  ;
    	}
    
    	public int subtract(int a, int b) {
    		return a-b ;
    	}
    
    	public int multiply(int a, int b) {
    		return a * b ;
    	}
    
    	public int divide(int a, int b) throws ArithmeticException {
    		return a /b ;
    	}
    }
  2. This is the class that has to be exposed as the Web Service and we write the funky TestRunner.java class to do all out operations like creating WSDL file, creating stub file etc.
  3. Generate WSDL file using Java2WSDL: Axis has a tool called Java2WSDL, which generates a WSDL file for a web service using a Java class. Java2WSDL file takes the following arguments.
    1. o – name for WSDL file -> calculator.wsdl
    2. n – target namespace -> mx:com.itechgenie.services.Calculator
    3. l – url of web service -> http://<host:port>/<Project-Name>/services/calculator

    Summing up the above arguments the following command line arguments is created.

    String java2wsdlArgs[] = {"-ocalculator.wsdl", "-nmx:com.itechgenie.services.Calculator", "-v", "-lhttp://localhost:8080/axis/services/calculator", "com.itechgenie.services.Calculator"} ;

    Read this Article on how to run the command line java tools from Eclipse.
    You can run the Java2WSDL as follows in the TestRunner class. Naah, don’t ask how, just put the following lines the main method and press CTRL + F11.

    try {
    	Java2WSDL.main(java2wsdlArgs) ;
    } catch (Exception e) {
    	e.printStackTrace() ;
    }

    The Java2WSDL class has the System.exit(0); method called from inside. So lines after the Java2WSDL will not be executed. To get the other arguments supported you can just run Java2WSDL.main(new String[0]) ;. This will display all the arguments supported by Java2WSDL Utility and this works for other utilities also.
    After running this Utility you will find the calculator.wsdl file created in the root folder of the Project.

  4. Generate Server side and Client side codes using WSDL2Java: WSDL2Java is another tools provided by the AXIS, which can generate server side and client side Java classes using a WSDL file. These classes are needed for deploying the web service and also for accessing the web service using a Java client. This tool expects the following argument which includes the WSDL file generated in the last step.
    1. o – output folder -> src
    2. p – package for generated classes -> mx:com.itechgenie.services. generated
    3. s – generate server side classes as well
    4. *.wsdl – WSDL file of any web service

    Summing up the above arguments the following command line arguments is created.

    String wsdl2javaArgs[] = {"-osrc", "-pcom.itechgenie.generated.service", "-s", "calculator.wsdl", "-v"} ;

    Read this Article on how to run the command line java tools from Eclipse.
    Now run the WSDL2Java utility as follows.

    try {
    	WSDL2Java.main(wsdl2javaArgs) ;
    } catch (Exception e) {
    	e.printStackTrace() ;
    }

    Once the above command is run, Just refresh the project in eclipse, you will find the following files created inside the “com.itechgenie.generated.service” package.

    1. Calculator.java
    2. CalculatorService.java
    3. CalculatorServiceLocator.java
    4. CalculatorSoapBindingImpl.java
    5. CalculatorSoapBindingStub.java
    6. deploy.wsdd
    7. undeploy.wsdd

    The above files can be used in both Server and Clients side as Skeleton (CalculatorSoapBindingImpl.java) and the Stub (CalculatorSoapBindingStub.java) respectively.

  5. Binding the business logic with the Skeleton: Take the Skeleton file and you will find the exact methods that were available in our Business logic class (Calculator.java.).
    Create a instance of the Business class and invoke the appropriate method from the skeleton as follows (Find the lines highlighted in yellow.).

    package com.itechgenie.generated.service;
    
    import com.itechgenie.services.Calculator;
    
    public class CalculatorSoapBindingImpl implements com.itechgenie.generated.service.Calculator{
    
    	Calculator calculatorImpl = new Calculator() ;
    
        public int add(int in0, int in1) throws java.rmi.RemoteException {
        	return calculatorImpl.add(in0, in1) ;
        }
    
        public int subtract(int in0, int in1) throws java.rmi.RemoteException {
        	return calculatorImpl.subtract(in0, in1) ;
        }
    
        public int divide(int in0, int in1) throws java.rmi.RemoteException {
        	return calculatorImpl.divide(in0, in1) ;
        }
    
        public int multiply(int in0, int in1) throws java.rmi.RemoteException {
        	return calculatorImpl.multiply(in0, in1) ;
        }
    
    }

    That’s it; we are now done with the development part of the Web Service. All we have to do is to configure to make the service up and running.

  6. Last configurations to make our service available: Open the server-config.wsdd file inside the WEB-INF folder. You will find the following lines.
      <!--  Your Service from the deploy.wsdd file - Starts here -->
    
      <!--  Your Service from the deploy.wsdd file - Ends here -->

    Keep the file aside and open the deploy.wsdd from the WSDL2Java generated files. Copy the <service> … </service> tag completely and paste in between the comments said above.

  7. Conclusion: You can follow the steps 6 to 11 and create as many services as you want and paste them in the server-config.wsdd.
    With this the configurations for the Web Service is over. Export the Project as a War and deploy it in Web Server and point to the URL http://<host:port>/<Project-Name>/services
  8. This URL should display all the services generated from steps 6 to 11 with the links the WSDL files for the above.

    Click here to download the sample project.

Create Web Services using Axis Java2WSDL, WSDL2Java and Eclipse for all Servers manually – Part 1

There a lot of Web Service implementations available in market. The most widely used among them is the Axis way of implementation. There are a lot of Examples available in the web to create expose, consume the Web services using the Axis packages. But it is not feasible to work get the Axis complete packages inside corporate offices all of a sudden and yes I faced the same situation.

After some investment of time I found some funky stuff in web to create a Web Service with just a couple of jars in hand and off-course with the help of Eclipse.

Prerequisites:

  1. Eclipse, any version should be ok, but I was using the Eclipse Indigo with Ant installed in it.
  2. The set of jars needed. Jars are included in the Project sample.
    1. axis.jar
    2. commons-discovery-0.2.jar
    3. commons-logging.jar
    4. jaxrpc.jar
    5. log4j-1.2.15.jar
    6. saaj.jar
    7. wsdl4j.jar
    8. The sample web.xml, server-config.wsdd (These will be used later in the development steps).

Steps to develop Web Services:

  1. Create a Dynamic Web Project “SampleWebService” in Eclipse.
  2. Place the above said jars in the WEB-INF/jars folder.
  3. Open the Web.xml file and copy the following contents into it somewhere between tags. These contents are available in the sample attached.
      <servlet>
        <display-name>Apache-Axis Servlet</display-name>
        <servlet-name>AxisServlet</servlet-name>
        <servlet-class>org.apache.axis.transport.http.AxisServlet</servlet-class>
      </servlet>
      <servlet-mapping>
        <servlet-name>AxisServlet</servlet-name>
        <url-pattern>/servlet/AxisServlet</url-pattern>
      </servlet-mapping>
      <servlet-mapping>
        <servlet-name>AxisServlet</servlet-name>
        <url-pattern>*.jws</url-pattern>
      </servlet-mapping>
      <servlet-mapping>
        <servlet-name>AxisServlet</servlet-name>
        <url-pattern>/services/*</url-pattern>
      </servlet-mapping>
      <servlet>
        <display-name>Axis Admin Servlet</display-name>
        <servlet-name>AdminServlet</servlet-name>
        <servlet-class>org.apache.axis.transport.http.AdminServlet</servlet-class>
        <load-on-startup>100</load-on-startup>
      </servlet>
      <servlet-mapping>
        <servlet-name>AdminServlet</servlet-name>
        <url-pattern>/servlet/AdminServlet</url-pattern>
      </servlet-mapping>
  4. Copy the server-config.wsdd next to web.xml file. We will reuse this file once again after complete the business logic of the server.
  5. Now the basic configurations are complete, we have to develop the business logic for the Web Service. In my example I have taken the Old school Calculator sample.
    Click here to go to the next Part of this article.