Building modular cloud apps with osgi oreilly media. The osgi alliance, formerly known as the open services gateway initiative, is an open standards organization founded in march 1999 that originally specified and continues to maintain the osgi standard the osgi specification describes a modular system and a service platform for the java programming language that implements a complete and dynamic component model, something that. Applications, in the form of bundles, can be remotely installed, started, stopped, updated, and uninstalled without requiring a restart. Richard nicholson, paremus ceo, president of the osgi alliance in writing this book, kirk has done the software community a. Over 60 recipes to help you get the most out of your apache karaf deployments. A handson guide to equinox and the osgi framework in osgi and equinox. Youll quickly get started with eclipse bundle tooling, create your first osgi based system, and move rapidly to. Apache karaf provides the following this website uses cookies to ensure you get the best experience on our website. Similar to netbeans, it is also a platform for richclient application, and it is built around the osgi container architecture, which itself is a topic that can fill a book like this. The osgi container provides a set of additional features on top of the osgi framework, as shown in the following diagram. Because of its unique architecture, you can modify, add, remove, start, and stop parts of an application without. Thats the main differentiator between this and the other books about osgi osgi and equinox. The osgi alliance named osgi cloud activities a strategic initiative for 2015.
The ones, who try finding workarounds, will feel the same. Java application architecture lays the foundation youll need to incorporate modular design thinking into your development initiatives. Creating modular applications in java pdf, epub, docx and torrent then this site is not for you. Io access, data services, watchdog, network configuration and remote management.
The stack assumed in part 2 by the authors consists of a regular modern html 5 rich client framework on top of restful data services exposed by osgi application modules running in an osgi container with amdatu components and an embedded servlet. The book will be of particular interest to enterpriselevel developers and architects. Before it walks you through eighteen patterns that will help you architect modular software, it lays a solid foundation that shows you why modularity is a critical weapon in your arsenal of design tools. Osgi in action provides a clear introduction to osgi concepts with examples that are relevant both for architects and developers. Osgi the sling application is built as a series of osgi bundles and makes heavy use of a number of osgi core and compendium services sling api to implement content based web applications with sling, an api has been defined, this extends the servlet api and provides more functionality to work on the content. A proven approach for developing modular applications. A second approach is to pass in environment variables to your container. Along with gofs design patterns, kirk knoernschilds java application architecture is a mustown for every enterprise developer and architect and on the required reading list for all paremus engineers. Container architecture presents the findings of three years of research into container architecture, showcasing more than 140 top projects with detailed fullcolor photographs and full resource lists. Net, osgi, or jigsaw or you want to build more modular software, the patterns in this book help you do that. Microservices is an architecture style, in which a single application is composed of small independent processes that use lightweight communications and languageagnostic apis. A stepbystep beginners guide to implementing a reallife osgi application, with the apache felix 3.
Some sentences of the chapter marshes, bogs, swamps, and other messes of the book the clean coder describes the situation pretty well. After reading this chapter i was more motivated to start using felix. First, it provides a clear introduction to osgi concepts with examples that arerelevant both for architects and developers. Kirk knoernschild introduces his book, where he explains that whether youre using java or.
Osgi has a mature capability model for specifying service and other dependencies. Osgi technology is a set of specifications that define a dynamic component system for java. The modularity patterns are not specific to the java platform. The osgi alliance, formerly known as the open services gateway initiative, is an open standards organization founded in march 1999 that originally specified and continues to maintain the osgi standard the osgi specification describes a modular system and a service platform for the java programming language that implements a complete and dynamic component model, something that does not exist. In this book, i show how the osgi technology can be used to write better. Osgi is just a tiny layer that provides the runtime environment for well behaved modules and yells when they misbehave. You will find lots of inspiration from other peoples projects. In an osgi framework, the same bundle the deployment component of an application can coexist with different versions. Building systems from inhouse and offtheshelf modules significantly reduces complexity and thus development and maintenance expenses. Osgi framework architecture three conceptual layers. Osgi framework architecture consists three conceptual layers.
Osgi is a module system that is compatible with systems that are based on java and implements a dynamic component model. Osgi cloud activities are based on industry needs and perspectives collected by the osgi alliance from members and osgi cloud workshop attendees. Modularity patterns with examples using osgi right now. I find the osgi specs pretty readable and i recommend you print out the flowchart that shows the algorithm for class loading. Osgi is a javabased framework for creating applications as a set of interconnected modules. In osgi we typically use configuration admin to configure components. Easy to transport, environmentally friendly, reusable and recyclable, container buildings are the home of the future today. Osgi lets you install, start, stop, update, or uninstall modules at execution time without taking down your entire system. They can be applied on any platform by treating the unit of. The following is a short list of highlights of sling. Highly recommended for anyone responsible for keeping a large software project sane, whether or i love how this book emphasizes that architecture is not just about. Osgi, microservice, containers, and serverless computing. Osgi in action is a comprehensive guide to osgi with two primary goals. Components communicate locally and across the network through services an application in this context represents the functionality desired by the organization.
Its the backbone of the eclipse plugin system, as well as many java ee containers, such as glassfish, geronimo, and websphere. Building microservices in osgi with the apache karaf framework. Modularity patterns with examples using osgi robert c. The remainder of this book will be focused on using osgi to achieve modularity. If tiered, you can convert the middleapptier to run in an osgi container. Other pain points are hibernate and jakarta commons logging. One of the things new to me was the web management console. Behind that facade, the newinstance method tries every class loader trick in the book and some that arent to create an instance of an implementation subclass. The osgiopen services gateway initiative framework provides a dynamic modular architecture which has been used in. The goal of jbi is to allow components and services to be integrated in a vendor independent way, allowing users and vendors to plug and play. Osgi is the only mature modularity solution for java today, and that is unlikely to change anytime soon. Oreilly members get unlimited access to live online training experiences, plus books. The architecture described in the book makes sense both for on premise and for in the cloud.
Modularity patterns with examples using osgi is kirk knoernschilds seminal book on a pattern catalogue for modular systems design. Also, this book shows how you can use osgi with existing jee services, such as jndi and jta. A very nice addition to manage your felix container. In my teams experience, weve found trying to do webstuff in osgi painful. If you want to know more on osgi, it is not exactly the book youre looking for except that the examples are presented with osgi osgi in action is the reference. If youre looking for a free download links of osgi in action. The ones, who try to use monoholitic libraries in an osgi environment will feel pain and will say that osgi juts hinders. The amdatu configurator is an extension to this, which can read keyvalue and xml files. Apache karaf is more than just an osgi based runtime container. Finally, the book describes some of the common pitfalls during bundle development, and gives hints on troubleshooting them in felix. Docker makes this easy, you can pass in variables using the e parameter to docker run. A roadmap for enterprise development 01 by knoernschild, kirk isbn.
Java application architecture is not only about isolated work, it is a complete and constant effort to guide teams. The author did a good job describing what you can do with gogo and why it is so nice to use for your container interaction. These specifications enable a development model where an application is composed of several components which are packaged in bundles. Ive just started hearing the term osgi being used while reading tutorials on common java ee containers such as glassfish and spring, however i have been unable to find a simple, straightforward, easytounderstand explanation of what osgi is that an enterprise novice such as myself would understand can someone provide such a dummyproof explanation. Osgi reduces complexity by providing a modular architecture for todays largescale distributed systems as well as small, embedded applications.
Osgi is not a secret sauce that will make the applications instantaneously modular. Kura osgibased application framework for m2m service. Its the name the osgi container uses to refer to the bundle. The goal of the book is mostly achieved and people who enjoy reading books as a guide throughout the stages of application development will find it deeply engaging. Then, it explores numerous practicalscenarios and techniques, answering questions like. Osgi was chosen due to its high degree of modularity. Provide an osgi based container for m2m applications running in service gateways.
The osgi core spec defines a layered architecture that determines. Apache servicemix is an distributed esb built from the ground up on the java business integration jbi specification jsr 208 and released under the apache license. Browse the amazon editors picks for the best books of 2019, featuring our. Just like object oriented forced structured developers to think differently, modularity forces todays developers to shift paradigm and code. Free download adobe after effects cc classroom in a book 2014 release free download advanced actionscript 3 with design patterns. Everyday low prices and free delivery on eligible orders. Creating highly modular java systems is heavily focused on the eclipse ecosystem. Enterprise systems can use osgi to improve the maintainability of runtime infrastructures. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. Most of the developers use eclipse and, almost exclusively, it is the choice when developers create code for the ibm websphere application server. A strong security mechanism allows you to define the boundaries of the application, thereby avoiding unwanted spaghetti architecture.
Originally intended to bring java into embedded systems. Once called the open services gateway initiative, the osgi alliance now refers to the framework specification as osgi or the osgi service platform. Osgi and docker, a perfect team paul about software. Osgi is a javabased framework for creating applications as a set of. Creating highly modular java systems, three leading experts show developersfor the first timeexactly how to make the most of these breakthrough technologies for building highly modular dynamic systems.
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