1.
How to build a custom stack with
WSO2 Carbon
Shameera Ratnayaka
Software Engineer
Manoj Kumara
Software Engineer

2.
150+ globally positioned support
customers

3.
Topics
● The feature/component concept in the WSO2 Carbon
platform.
● Installing features using the Feature Manager.
● How to create your custom products for cluster wide
deployment.
● Scripting feature installations for automation.
● Configuring logs/adding configs/etc.

4.
What is Carbon
Carbon is a modular server runtime based on OSGi
Built on top of Carbon are a set of middleware
servers (App Server, ESB, Identity, API Manager, etc)
Re-configurable
» Install new features, uninstall, revert
Carbon includes a set of re-usable core components
● Clustering, User Management, Logging, JMX, ...

5.
WSO2 Carbon based Products
Features
• Service Management Feature
• Proxy Services Features
• Transport Management Feature, etc..

6.
Features in Carbon

7.
What is a Feature
In Eclipse world
– Feature is a grouping of set of logically related plug-ins/ OSGi bundles
– Feature can be installed into Eclipse platform using its Update Manager
In Carbon world
– Feature can be thought of as an installable form of one or more logically
related Carbon component
• Service Management Component
– What you develop
• Service Management Feature
– What you install
– Feature is a grouping of one or more logically related Carbon components
– Features can be installed into Carbon based product using Feature Manager

8.
Features
Allows you to specify pre-requisites of your Carbon
component.
– Other dependent features, bundles.
– Dependency Management.
• Are installable Units which can be installed into any
Carbon based product.
• Can be installed using the WSO2 Carbon Feature
Manager or by using a script
• Can be shared with others by packaging features as a
Repository (Update Site in eclipse terms).

9.
What is a Carbon Component
● A set of OSGi Bundles.
● Lives in the Carbon Framework. Hence should conform to rules define
in the Carbon Framework.
● Uses Core Carbon Services
○ Via OSGI service registry
e.g. Registry Service, UserManager Service, etc
● Two aspects/ BE-FE Separation
○ Every component has a core runtime, a clean SOA management interface, a
well-defined front-end console component
○ Back-end Runtime
○ Front-end Console

10.
The big picture

11.
Equinox P2
● A provision platform for OSGi based systems.
● p2 stands for “Provisioning Platform”
● Provides a well defined model for provisioning OSGi
bundles
● p2 allows us to manage components in a controlled
manner
● Install, Uninstall, Revert
● Based on a web or file based repository
○ Can be hosted internally for an organization
● Three approaches:
○ Command line
○ Web console
○ Secure remote API

12.
Carbon Component: Development
Process
1. Develop the Carbon component
○ Back-end component (BE OSGi bundles)
○ Front-end component (FE OSGi bundles)
○ Common bundles, if any
2. Develop the corresponding feature
○ BE/Server Feature
○ FE/UI Feature
○ Composite Feature
3. Install into a Carbon based product
○ By integrating with the product build system
○ By developing a feature repository and installing using Feature
Manage

13.
Eclipse p2
● Manages the packaging of OSGi bundles
into features
● Supports deploying, undeploying,
checkpoints
● Advanced features include shared
repositories

14.
p2 in Eclipse

15.
p2 in Carbon

16.
Feature Provisioning

17.
Student Manager Component
Lets develop a sample Carbon component to understand
the development process as well as the build process.
• Student Manager component
○ Consists of a BE runtime which exposes a Web services to
• Add new students
• Get the list of students
○ Consist of a FE console which displays the available student
information on the Carbon management console.
• Student Manager Feature
○ org.wso2.carbon.student.mgt.server.feature
○ org.wso2.carbon.student.mgt.ui.feature
○ org.wso2.carbon.student.mgt.feature

18.
Developing the BE Component
● Some actual server logic plus an admin
service to manage it
● Add some special sauce into the services.
xml to let us know it’s an admin service
● component.xml configures permissions

19.
We use Maven as our build tool.
• Building Carbon components/OSGi bundles
– Use Maven Bundle plugin to build OSGi bundles
https://svn.wso2.org/repos/wso2/carbon/kernel/branches/4.1.0/core/org.
wso2.carbon.core/4.1.0/pom.xml
• Building Features
– Use Maven P2 Feature plugin (Developed at WSO2)
– Use p2-feature-gen goal
https://svn.wso2.org/repos/wso2/carbon/kernel/branches/4.1.0
/features/org.wso2.carbon.core.feature/4.1.0/pom.xml
• Building a Repository
– Use Maven P2 plugin
– P2-repo-generator goal
https://svn.wso2.org/repos/wso2/carbon/kernel/branches/4.1.0
/features/pom.xml
Carbon Component: Build Process

20.
Demo
Create custom component

21.
Acquiring a OSGi service declaratively
/**
* @scr.component name="org.wso2.carbon.student.mgt" immediate="true"
* @scr.reference name="registry.service" interface="org.wso2.carbon.registry.core.service.
RegistryService"
* cardinality="1..1" policy="dynamic" bind="setRegistryService" unbind="unsetRegistryService"
*/
public class StudentRegistryService {
public static RegistryService registryService;
protected void setRegistryService(RegistryService registryService) {
StudentRegistryService.registryService = registryService;
}
protected void unsetRegistryService(RegistryService registryService) {
StudentRegistryService.registryService = null;
}
}

22.
Deployment Synchronization

23.
Clustering

24.
Install features in build time
- Why?
- can we do this with feature manager UI?
- Then how we do that?
- Carbon-p2 maven plugin
- Generate p2 repository
- Install feature

25.
Configuration files
- axis2.xml
- carbon.xml
- master-datasources.xml
- authenticators.xml
- registry.xml
- cache.xml
- user-mgt.xml
- log4j.properties
- .......

26.
Add and Edit Configurations
conf
├── axis2
│ ├── axis2_client.xml
│ ├── axis2.xml
│ └── tenant-axis2.xml
├── carbon.xml
├── datasources
│ └── master-datasources.xml
├── etc
│ ├── cache.xml
├── log4j.properties
├── registry.xml
├── security
│ ├── authenticators.xml
├── tomcat
│ ├── carbon
│ │ ├── META-INF
│ │ │ └── context.xml
│ │ └── web.xml
│ ├── catalina-server.xml
│ ├── tomcat-users.xml
│ └── web.xml
└── user-mgt.xml

27.
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