This document provides an introduction to OSGi using Apache Karaf. It discusses the problems that OSGi and Karaf aim to solve regarding dependency management, dynamic behavior, and modularity. It then summarizes OSGi's architecture including modules, lifecycles, and services. Finally, it outlines key aspects of Apache Karaf like its shell, deployer, features concept, security, and logging service.

1. Introduction to OSGi using Apache Karaf Ioannis CanellosJHUG / 16 April 2011

2. Presenting today…OSGiOpen Services Gateway initiative, since 1999Initially targeted embedded devicesOSGi containers: Felix, Equinox, Knoperfish, ConciergeMost known use is Eclipse IDEApache KarafApache OSGi runtime runs on any OSGi containerBorn inside Service Mix, now is Top level projectStandard runtime for Geronimo, Service Mix, SlingEcosystem for deploying OSGi/EE applications

3. Part IIntroduction to OSGi

4. Introduction to OSGiProblem SolutionArchitectureToolsOSGi in the EnterpriseQuestions & Answers

5. The problemaspects Dependency managementVersion HellConflicting dependenciesClass loading issuesDynamic behaviorDifficulties to control component lifecycleLack of a pure modularity solution

6. The problemsDependency managementLarge number of transitive dependenciesConflicts among among dependenciesClass loading issuesBoot class loaderJTASystem class loaderJTAwarwar

7. The problemsDynamic BehaviorComponents & Services need come and goComponents need to get updated / replacedComponents need to started / stoppedReal life examplesEclipse IDEAdding/Removing “plugins”EbayMultiple version of the same component

8. The problemsModularityThe JVM does not address need for modularityThe class path paradoxThe jar is a “black box”No dependencies & No versionThe pastitsioexampleThe “WORA” promise was repeatedly failedJavaBeansEJBsHas the quest for modularity failed ?Project Jigsaw will be shipped with JDK 8 OSGi is already here

9. The OSGi SolutionOverviewA Layer …A deployment infrastructureBundles = class + metadata (import/exports)Bundles have a lifecycleBundles have their own Class loaderClass loading delegation between dependant bundles A service platformDefines a Service RegistryBundles provide or request servicesThe service can “come and go”

10. Architecture

11. Architecture Execution EnvironmentThe Runtime where the bundles liveA bundle can bound to an Execution EnvironmentJRE-1.5JJRE-1.3OSGi/Minimum-1.0

12. Architecture Module LayerBundles import, export or have private packagesEach package can be assigned version rangeA bundle (fragment)can be attached to a bundle (host)Export Packagejavax.transaction 1.01BImport Packagejavax.transaction [1.0,1.1)Export Packagejavax.transaction 1.1Bundle Name: JMS APIImport Package: javax.transactionExport Package: javax.jmsBundle-RequiredExecutionEnvironment: J2SE-1.5

13. Architecture Module Layera MANIFEST.MF exampleManifest-Version:1.0Import-Package:javax.transaction;version="1.1”, javax.transaction.xa;version="1.1”Export-Package:javax.jms;version="1.1”Bundle-SymbolicName:org.apache.geronimo.specs.geronimo-jms_1.1_specTool:Bnd-0.0.227

14. InstalledStartingArchitecture Lifecycle Layerstartupdate refreshresolveStartedResolveduninstalluninstallstopStoppedUninstalled

15. Architecture Service LayerEach bundle can register or lookup a ServiceEach service corresponds to one or more interfacesEach service can be assigned and queried using propertiesService RegistryregisterlookupServiceProviderService Consumer

16. OSGi Tools working with servicesManaging Services programmaticallyUsing the OSGi blueprintSpring Dynamic ModulesApache AriesFelix i-Pojo

17. OSGi Tools creating bundlesManually providing the MANIFEST.MFBnd command line toolMaven Bundle Plug-inSpring’s BundlorMaven plug-in flavorCommand line flavor

18. OSGi Tools OSGi Bundle RepositorySimplifies the provisioning of bundlesThe “apt-get install” for the OSGiIntegrates with public repositoriesEclipse OrbitSpring’s Enterprise Bundle Repository

19. OSGiEnd of Part IQuestions & Answers

20. Part IIGetting started with Apache Karaf

21. Apache KarafagendaOverview Shell ConsoleDeployerFeatures ConceptSecurityLogging ServiceDemoQuestions and Answers

22. Apache KarafOverviewBorn as Service Mix Kernel projectGrown inside Apache Felix projectBecome a Top Level Apache project last year

23. Apache KarafShell ConsoleExtensible Auto complete & coloring supportRich command set, covers most OSGi concepts/servicesSpecial commands for the development phase

24. Apache KarafDeployerFile ScannerWar TransformerConfigurationBundlesTransformationSpringTransformerBlueprintTransformerConfigurationAdminURLHandlerMaven HandlerHTTP HandlerHot deploymentLarge number of supported artifactsLarge number of installation mediumsOBR Handler

25. Apache KarafFeatures ConceptA Karaf feature is a descriptor which defines…A set of bundlesA set of configurationsA set of other featuresAllows provisioning of applicationsMaven integrationOBR integration

26. Apache KarafFeatures Example<feature name="http" version=”2.2.0” resolver=“(obr)”><configname="org.ops4j.pax.web”> org.osgi.service.http.port=8181 </config><feature version="[7.0,8.0)">jetty</feature> <bundle dependency=“true”>mvn:javax.servlet/servlet-api</bundle> <bundle>mvn:org.ops4j.pax.web/pax-web-api</bundle></feature>

27. Apache KarafSecurityJAAS based securityMultiple login module implementationsProperty Login ModuleJDBC Login ModuleLDAP Login ModuleCommand line supportProvisioning of any JASS realm Add users roles etc

28. Apache KarafLogging ServiceCentralized Logging configurationSupports most logging APIsLog4JSlf4j Commons LoggingCommand line supportclear, display, tail change threshold etc.OSGi integrationper bundle appender, osgi specific attributes

29. Apache Karaf End of Part IIQuestions & Answers

30. Thank you