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. A stepbystep beginners guide to implementing a reallife osgi application, with the apache felix 3. 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. People have written entire books about osgi, so were not going to go over everything the framework stands for. The book then kicks off the bookshelf project, a case study that will be used to progressively explain the important concepts around osgi using the felix framework the bookshelf project feature trail will set the context to explain osgi headers, the bundle activator, the bundle context and so on as the reader implements the bookshelf step by step, they learn about obr repositories.
Rfc documents are design documents and found in numbered subfolders of the rfcs folder the documents in this repository are nonfinal specification design work which either propose to modify existing published osgi specifications from the osgi. Enterprise osgi in action is a handson guide for developers using osgi to build the next generation of enterprise java applications. Richard nicholson, paremus ceo, president of the osgi alliance in writing this book, kirk has done the software community a. Io access, data services, watchdog, network configuration and remote management. One of the things new to me was the web management console.
The osgi container provides a set of additional features on top of the osgi framework, as shown in the following diagram. Most applications either run standalone or in a container framework such as j2ee, and j2ee was developed before osgi. Learning apache karaf will benefit all java developers and system administrators who need to develop for andor operate karafs osgibased runtime. Jacket title from title screen includes bibliographical references and index.
After a quick but detailed understanding of osgi and karaf, this book takes you through the concept of provisioning clusters and then covers what cellar is and how to use it. Gerd wutherich, nils hartmann, bernd kolb, matthias lubken. Docker makes this easy, you can pass in variables using the e parameter to docker run. To hide the differences of the launching mechanism, sling internally registers a servlet with an osgi. Kura osgibased application framework for m2m service. 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 handson guide to equinox and the osgi framework in osgi and equinox.
The architecture described in the book makes sense both for on premise and for in the cloud. Sep 22, 2016 the flagship feature of java 9 will be the new java platform module system jpms. Osgi iot expert group and osgi architecture may 2018 osgi services using services is a powerful way for bundles to collaborate services advertise their public interfaces this provides a typesafe way to identify what a service does services can be registered and unregistered dynamically clients can be noti. 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. Traditional javaee webapps can be deployed, in addition to jetty contexthandlers, along with osgi web bundles. The book is a fastpaced guide full of stepbystep instructions covering all aspects of application development using apache karaf. 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. Although osgi has been criticized for being too complex to use in the past, recent improvements to tooling and frameworks have changed this completely. Pro spring dynamic modules for osgi service platforms. Karaf provides a distribution based on felix by adding other features such as a console, an ssh remoting mechanism, a file deployer and more. A module blueprint is a configuration file that describes how finegrained components are wired. Microservices is an architecture style, in which a single application is composed of small independent processes that use lightweight communications and languageagnostic apis. 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. You do not have to use this service for configuration, but it is typically the most convenient way of configuring applications deployed in fuse esb enterprise including fabs and osgi bundles.
Would osgi be a good choice for developing a new large. These specifications enable a development model where an application is composed of several components which are packaged in bundles. Container for osgi blueprint components the osgi application framework includes the apache software foundations aries open implementation of the osgi version 4. Youll quickly learn how to use osgi, through concise code examples and a set of best practices derived from the authors experiences with realworld projects. The ones, who try finding workarounds, will feel the same. By presenting relevant examples and case studies, this book guides the reader through the maze of new standards and projects. For osgi based component development its more important to focus on the components than on the components framework. Oct 19, 20 this 3rd part is the small one only 21 pages. This architecture significantly reduces the overall complexity of building, maintaining and deploying applications. The blueprint container spec is part of the osgi 4. The osgi blueprint container specification defines a dependency injection framework for osgi derived from the spring dynamic modules project. Once called the open services gateway initiative, the osgi alliance now refers to the framework specification as osgi or the osgi service platform.
Rfp documents are requirements documents and found in the rfps folder. Easy to transport, environmentally friendly, reusable and recyclable, container buildings are the home of the future today. Finally, the book describes some of the common pitfalls during bundle development, and gives hints on troubleshooting them in felix. In osgi we typically use configuration admin to configure components. Building systems from inhouse and offtheshelf modules significantly reduces complexity and thus development and maintenance expenses. The osgi open services gateway initiative framework provides a dynamic modular architecture which has been used in many applications such as eclipse equinox, apache felix, etc. The specification outlines open standards for the management of voice, data, and multimedia wireless and wired networks. Osgi framework architecture three conceptual layers.
Apr 24, 2020 the osgi alliance also grants you a perpetual, nonexclusive, worldwide, fully paidup, royalty free, limited license without the right to sublicense under any applicable s, to create andor distribute an implementation of the distribution that. Some sentences of the chapter marshes, bogs, swamps, and other messes of the book the clean coder describes the situation pretty well. So osgi is primarily good for systems where you want many nonweb applications running under a single control point rather than having them splattered around the os in. Osgi is not a secret sauce that will make the applications instantaneously modular. These extensions include but they are not limited to. Oct 24, 20 learning apache karaf will introduce developers and administrators alike to the osgibased container, and impart best practices by example. A proven approach for developing modular applications. Provide an osgi based container for m2m applications running in service gateways. After reading this chapter i was more motivated to start using felix. Apache karaf provides the following this website uses cookies to ensure you get the best experience on our website. Java application architecture is not only about isolated work, it is a complete and constant effort to guide teams.
Osgi and docker, a perfect team paul about software. Dont miss these great shipping container architecture books for sale on amazon. Overall, the osgi blueprint container specification describes an application architecture in which application modules are implemented as osgi bundles with a module blueprint the configuration information and a runtime context created from that blueprint. Osgi is just a tiny layer that provides the runtime environment for well behaved modules and yells when they misbehave. Building an iot architecture with a modular osgi approach futureproofs investments, reduces development cycles and enables rapid and costeffective delivery of new. Learning karaf cellar starts with an introduction to some of the key features of karaf. Despite the growing popularity of container architecture theres still a limited number of books published on the subject shipping containers are affordable, adaptable and turn heads when used to create buildings so its easy to get excited about the possibilities. Strong isolation and well defined boundaries between software artifacts. Sep 25, 2014 the ones, who try to use monoholitic libraries in an osgi environment will feel pain and will say that osgi juts hinders. If youre an experienced java developer in the enterprise, this practical, handson book shows you how to use osgi to design, develop, and deploy modular cloud applications. Osgi and docker, a perfect team paul about software development. Osgi lets you install, start, stop, update, or uninstall modules at execution time without taking down your entire system. Just like object oriented forced structured developers to think differently, modularity forces todays developers to shift paradigm and code.
Components communicate locally and across the network through services. Each bundle is a tightly coupled, dynamically loadable collection of classes, jars, and configuration files that explicitly declare their external dependencies if any. The lightweight osgi container label is contrasting karaf with more feature rich osgi containers, not with felix to quote guillaume nodet karafs author from here. Osgi, on the other hand, is a container architecture. The definitive guide to using enterprise osgi in the real world. 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. The following is a short list of highlights of sling. Originally intended to bring java into embedded systems. One of the key features of that multibundle solution in. Provide an osgibased container for m2m applications running in service gateways. Currently doing agile development using multiple java open source frameworks such as hibernate, spring.
Slides and videos of the osgi community event talks. The amdatu configurator is an extension to this, which can read keyvalue and xml files. Jan 29, 2011 the book then kicks off the bookshelf project, a case study that will be used to progressively explain the important concepts around osgi using the felix framework the bookshelf project feature trail will set the context to explain osgi headers, the bundle activator, the bundle context and so on. Modules are peers which interact via the service registry. Components communicate locally and across the network through services an application in this context represents the functionality desired by the organization. The osgi service platform specification defines an open common architecture for service delivery and management using bundles. Osgi reduces complexity by providing a modular architecture for todays largescale distributed systems as well as small, embedded applications. Features in osgi applications are separated into bundles. The jetty osgi infrastructure provides a jetty container inside an osgi container. A problem you could solve using docker would be something like having multiple java.
The book shows you how to set up an apache karaf distribution, and how to arrive at a productionready deployment. This website uses cookies to ensure you get the best experience on our website. You will find lots of inspiration from other peoples projects. One of the key features of that multibundle solution in its associated github. Osgi is a javabased framework for creating applications as a set of interconnected modules. 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. Understanding how osgi framework works is useful for developing eclipse plugins and many other molecularity applications. The ones, who try to use monoholitic libraries in an osgi environment will feel pain and will say that osgi juts hinders. Osgi has enjoyed wide adoption across a broad range of industries including industry 4. 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. Declarative services is very good but its not the only solution 6. The specification defines a component model for osgi based on the core spring framework in which an osgi bundle is augmented by an xml module blueprint. Given the maturity of osgi there were technical, political and commercial reasons why another java module system. Learning apache karaf will introduce developers and administrators alike to the osgibased container, and impart best practices by example.
As we have seen, sling may be launched as a standalone java application or as a web application inside any compliant servlet container. Introduction to osgi my background software developer for the last 3. An osgi service platform provides a standardized, componentoriented computing environment for cooperating networked services. Pro spring dynamic modules for osgi service platforms by daniel rubio is the first book to cover osgi as practically implemented by the worlds most popular, agile, and open source enterprise java framework, spring. A very nice addition to manage your felix container. It focuses on how to get the osgi application running outside the development environment, in a stand alone osgi container that is hosted in a cloud environment private or public. Modularity patterns with examples using osgi is kirk knoernschilds seminal book on a pattern catalogue for modular systems design. Osgi is the only mature modularity solution for java today, and that is unlikely to change anytime soon. Creating flexible applications with osgi and spring. Building modular cloud apps with osgi oreilly media. Im assuming were talking strictly about jvm based applications, so the rest of my answer comes from that point of view. In two previous articles, i introduced building an osgi bundle and the architecture of a multibundle osgi solution. A second approach is to pass in environment variables to your container. Osgi specifications are defined and maintained by the osgi alliance, an open standards organization.
Its the backbone of the eclipse plugin system, as well as many java ee containers, such as glassfish, geronimo, and websphere. The osgi configuration admin service defines a mechanism for passing configuration settings to an osgi bundle. The remainder of this book will be focused on using osgi to achieve modularity. Youll quickly get started with eclipse bundle tooling, create your first osgi based system, and move rapidly to. Instead we will only explain what it gives us and the way we use it in jitsi. Java application architecture lays the foundation youll need to incorporate modular design thinking into your development initiatives. The chapter explains again that the authors prefer apache felix over eclipse equinox.
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