OSGi provisioning deep dive and demo (Subsystems, Repository, Contracts and more) - D Bosschaert
- 1. Subsystems, Repository, Contracts and more... David Bosschaert OSGi Application Provisioning Deep Dive 1 of 41
- 2. About me David Bosschaert (davidb@apache.org) Works at Adobe R&D Basel Co-chair OSGi EEG Apache committer Open-source and cloud enthusiast 2 of 41
- 3. Topics A look at the latest Declarative Services Using Subsystems to package and deploy OSGi Repository to resolve dependencies Portable Java Contracts ... demo throughout ... 3 of 41
- 4. Running Example Device Monitor ... a little webapp to monitor all your gadgets ... 4 of 41
- 5. Declarative Services Being updated for Enterprise R6 Improved Configuration Admin integration Introspective API Prototype Service Factory ... other smaller improvements ... 5 of 41
- 6. DS Configured Component iimmppoorrtt javax.servlet.SSeerrvvlleett; iimmppoorrtt org.osgi.service.component.annotations.*; iimmppoorrtt org.osgi.service.http.HHttttppSSeerrvviiccee; @Component ppuubblliicc ccllaassss DDeevviicceeMMoonniittoorr { pprriivvaattee HHttttppSSeerrvviiccee httpService; @Reference ppuubblliicc vvooiidd setHttpService(HHttttppSSeerrvviiccee svc) { httpService = svc; } @Activate ppuubblliicc vvooiidd activate(MMoonniittoorrCCoonnffiigg cfg) { SSttrriinngg rootCtx = cfg.ctxPrefix(); iiff (!rootCtx.endsWith("/")) rootCtx = rootCtx + "/"; registerServlet(rootCtx + "dmon", nneeww MMoonniittoorrSSeerrvvlleett()); registerServlet(rootCtx + "device", nneeww DDeevviicceeSSeerrvvlleett()); } pprriivvaattee vvooiidd registerServlet(SSttrriinngg ctx, SSeerrvvlleett servlet) { httpService.registerServlet(ctx, servlet, nnuullll, nnuullll); } } 6 of 41
- 7. Configuration using Annotations ppuubblliicc @interface MMoonniittoorrCCoonnffiigg { SSttrriinngg ctxPrefix() ddeeffaauulltt "/"; bboooolleeaann autoRefresh() ddeeffaauulltt ffaallssee; iinntt interval() ddeeffaauulltt 30; } annotation used as an ordinary interface, with added defaults ... weird but works great ... 7 of 41
- 8. Example Bundle Manifest BBuunnddllee-MMaanniiffeessttVVeerrssiioonn: 2 BBuunnddllee-SSyymmbboolliiccNNaammee: devicemon-ds BBuunnddllee-VVeerrssiioonn: 0.0.1 SSeerrvviiccee-CCoommppoonneenntt: OSGI-INF/component.xml IImmppoorrtt-PPaacckkaaggee: javax.servlet;version="[2.5,3)", org.coderthoughts.devicemon.ssh;version="[1.0,2)", org.osgi.service.http;version="[1.2,2)" RReeqquuiirree-CCaappaabbiilliittyy: osgi.extender;filter:="(&(osgi.extender=osgi.component) (version>=1.2.0)(!(version>=2.0.0)))", osgi.whiteboard;filter:="(osgi.whiteboard=osgi.http)" Note that the javax.servlet import should really use contracts! 8 of 41
- 9. Finished app... 2 Bundles devicemon.jar depends on DS and HTTP Service devicemon-ssh.jar depends on Apache Mina SSHD 9 of 41
- 10. Deploy it... Now I want to easily deploy my app ⟱ create a Subsystem of it! 10 of 41
- 11. Subsystems OSGi Enterprise spec 134 A subsystem... collection of bundles put together feature - everything shared application - isolated, nothing shared out composite - configurable in-between a zip file with .esa extension can be nested can depend on bundles or other subsystems Subsystems can use OSGi Repositories to resolve dependencies 11 of 41
- 12. devicemon-ds.esa Just a zip file... $ tar tvf devicemon-ds.esa -rwxrwxrwx 99 8 JJaann 15:40 OSGI-INF/SUBSYSTEM.MF -rwxrwxrwx 18184 8 JJaann 16:01 devicemon-ds.jar -rwxrwxrwx 5968 8 JJaann 16:02 devicemon-ssh.jar Subsystem Manifest $ cat OSGI-INF/SUBSYSTEM.MF SSuubbssyysstteemm-SSyymmbboolliiccNNaammee: devicemon-ds SSuubbssyysstteemm-VVeerrssiioonn: 0.0.1 SSuubbssyysstteemm-TTyyppee: osgi.subsystem.feature note, I didn't put my dependencies in the .esa file 12 of 41
- 13. Feature subsystems devicemon-ds.esa: a Feature Subsystem All the bundles inside work just as shared bundles in OSGi Subsystem installed/started/stopped as 1 unit Dependencies pulled in either from .esa or from repository as needed are reference-counted 13 of 41
- 14. Apache Felix + Apache Aries Subsystems 14 of 41
- 15. Add HTTP subsystem 15 of 41
- 16. 3 bundles in 1 operation 16 of 41
- 17. Our subsystem doesn't install! NB: a failed subsystem install doesn't leave any bundles behind... 17 of 41
- 18. OSGi Repository OSGi Enterprise spec 132 Inspired by Felix OBR Simple but powerful Actual repo can be remote or local Find resources based on their capabilities any resource any capability OSGi has defined: standard Bundle capabilities Bundle, Subsystem resource types some more general capabilities 18 of 41
- 19. Add resources using standard XML Example <<rreeppoossiittoorryy increment='1389281419631' name='MyRepo' xmlns='http://www.osgi.org/xmlns/repository/v1.0.0'>> <<rreessoouurrccee>> <<ccaappaabbiilliittyy namespace='osgi.identity'>> <<aattttrriibbuuttee name='osgi.identity' value='org.apache.sshd.core'//>> <<aattttrriibbuuttee name='type' value='osgi.bundle'//>> <<aattttrriibbuuttee name='version' type='Version' value='0.9.0'//>> <<//ccaappaabbiilliittyy>> <<ccaappaabbiilliittyy namespace='osgi.content'>> <<aattttrriibbuuttee name='osgi.content' value='a1c64578808c38a63cd6563e9936f025638aeaf9de70f36765367db81c0afc38' <<aattttrriibbuuttee name='url' value='local-repo/sshd-core.jar'//>> <<aattttrriibbuuttee name='size' type='Long' value='464733'//>> <<aattttrriibbuuttee name='mime' value='application/vnd.osgi.bundle'//>> <<//ccaappaabbiilliittyy>> <<ccaappaabbiilliittyy namespace='osgi.wiring.package'>> <<aattttrriibbuuttee name='osgi.wiring.package' value='org.apache.sshd'//>> <<aattttrriibbuuttee name='version' type='Version' value='0.5.0'//>> <<aattttrriibbuuttee name='bundle-symbolic-name' value='org.apache.sshd.core'//>> <<aattttrriibbuuttee name='bundle-version' type='Version' value='0.9.0'//>> <<ddiirreeccttiivvee name='uses' value='org.apache.sshd.client'//>> <<//ccaappaabbiilliittyy>> <!-- More capabilities --> <<rreeqquuiirreemmeenntt namespace='osgi.wiring.package'>> <<ddiirreeccttiivvee name='filter' value='(&(osgi.wiring.package=org.slf4j)(version>=1.6.0)(!(version>=2.0.0)))'/> <<//rreeqquuiirreemmeenntt>> <!-- More requirements --> <<//rreessoouurrccee>> <!-- More resources --> <<//rreeppoossiittoorryy>> 19 of 41
- 20. Repository XML Format defined by OSGi Repository Spec Standard way to feed a repository with information Standard way for repositories to exchange data Generate it with the bindex/RepoIndex tool: https://github.com/osgi/bindex (https://github.com/osgi/bindex) 20 of 41
- 21. Repository Service Obtain resources from the repository Find a bundle... RReeppoossiittoorryy repo = ... // from Service Registry ... RReeqquuiirreemmeennttBBuuiillddeerr rb = nneeww RReeqquuiirreemmeennttBBuuiillddeerr("osgi.wiring.package"); rb.addDirective("filter", "(&(osgi.wiring.package=org.apache.ssh)(version=0.5.0))"); RReeqquuiirreemmeenntt req = rb.build(); CCoolllleeccttiioonn<RReessoouurrccee> bundleResources = repo.findProviders(req); ... or find some photo's from the North Pole ... RReeqquuiirreemmeennttBBuuiillddeerr rb = nneeww RReeqquuiirreemmeennttBBuuiillddeerr("com.acme.photo"); rb.addDirective("filter", "(latitude>=66.5622)"); RReeqquuiirreemmeenntt req = rb.build(); CCoolllleeccttiioonn<RReessoouurrccee> photoResources = repo.findProviders(req); 21 of 41
- 22. Add and prime a Repository 22 of 41
- 23. Our subsystem works! 23 of 41
- 24. Descriptor Subsystems A subsystem can be just a descriptor ... with all resources obtained from a Repository $ jar tvf generated/devicemon-ds-decl.esa 0 TThhuu JJaann 09 12:37:32 GMT 2014 OSGI-INF/ 175 WWeedd JJaann 08 15:50:28 GMT 2014 OSGI-INF/SUBSYSTEM.MF Subsystem Manifest $ cat OSGI-INF/SUBSYSTEM.MF SSuubbssyysstteemm-SSyymmbboolliiccNNaammee: devicemon-ds-decl SSuubbssyysstteemm-VVeerrssiioonn: 0.0.1 SSuubbssyysstteemm-TTyyppee: osgi.subsystem.feature SSuubbssyysstteemm-CCoonntteenntt: devicemon-ds;version=0.0.1, devicemon-ssh;version=0.0.1 24 of 41
- 25. Start with only Subsystems + Repository 25 of 41
- 26. Dependencies at work http.esa pulled in automatically 26 of 41
- 27. Unpredictable dependency both 0.9.0 and 0.9.1 satisfy requirement 27 of 41
- 28. Subsystem Deployment Descriptor Once QA-ed, create a DEPLOYMENT.MF to fix dependencies $ jar tvf generated/devicemon-ds-decl-dd.esa 283 WWeedd JJaann 15 16:39:34 GMT 2014 OSGI-INF/DEPLOYMENT.MF 175 WWeedd JJaann 08 15:50:28 GMT 2014 OSGI-INF/SUBSYSTEM.MF it can freeze deployments $ cat OSGI-INF/DEPLOYMENT.MF SSuubbssyysstteemm-VVeerrssiioonn: 0.0.1 SSuubbssyysstteemm-TTyyppee: osgi.subsystem.feature DDeeppllooyyeedd-CCoonntteenntt: devicemon-ds;deployed-version=0.0.1, devicemon-ssh;deployed-version=0.0.1 PPrroovviissiioonn-RReessoouurrccee: org.apache.sshd.core;deployed-version=0.9.1, org.apache.felix.scr;deployed-version=1.8.2, http-subsystem;type=osgi.subsystem.feature;deployed-version=1.2.0 note version 0.9.1 for org.apache.sshd.core Ensures that the runtime deployment is the same as the QA one. 28 of 41
- 29. SSHD dependency now as predicted 29 of 41
- 30. Portable Contracts Our bundle contains: IImmppoorrtt-PPaacckkaaggee: javax.servlet;version="[2.5,3)", This API is defined by the JCP. but... spot the problem! 30 of 41
- 31. Semantic Versioning ... versioning policy for exported packages. OSGi versions: <major>.<minor>.<micro>.<qualifier> Updating package versions: fix/patch (no change to API): update micro extend API (affects implementers, not clients): update minor API breakage: update major Using semantic versioning allows creating components that can work with future patches and other compatible releases of deps just Import-Package a range like: [5.3, 6) 31 of 41
- 32. javax.servlet Problem IImmppoorrtt-PPaacckkaaggee: javax.servlet;version="[2.5,3)", Servlet 3.0 is actually compatible with 2.5 JCP specs don't follow semantic versioning 3.0 is more of a marketing version But what version to use for javax.servlet in OSGi? Different providers made different decisions Some use 2.6 to export javax.servlet from Servlet 3 spec Others use 3.0 Some even use 0.0.0 This prohibits creating portable bundles using these APIs 32 of 41
- 33. Portable Java Contracts osgi.contract capability to the rescue client bundle requires capability with single 'marketing' or 'spec' version and also imports the package without version osgi.contract provider binds the contract version to package versions IImmppoorrtt-PPaacckkaaggee: javax.servlet, javax.servlet.http RReeqquuiirree-CCaappaabbiilliittyy: osgi.contract; filter:="(&(osgi.contract=JavaServlet)(version=2.5))" Enables creating portable bundles importing non-semantically versioned packages. 33 of 41
- 34. Our bundle manifest should really be BBuunnddllee-MMaanniiffeessttVVeerrssiioonn: 2 BBuunnddllee-SSyymmbboolliiccNNaammee: devicemon-ds BBuunnddllee-VVeerrssiioonn: 0.0.1 IImmppoorrtt-PPaacckkaaggee: javax.servlet, org.coderthoughts.devicemon.ssh;version="[1.0,2)", org.osgi.service.http;version="[1.2,2)" RReeqquuiirree-CCaappaabbiilliittyy: osgi.extender;filter:="(&(osgi.extender=osgi.component) (version>=1.2)(!(version>=2.0)))", osgi.whiteboard;filter:="(osgi.whiteboard=osgi.http) (version>=1.0)(!(version>=2.0)))", osgi.contract;filter:="(&(osgi.contract=JavaServlet) (version=2.5))" 34 of 41
- 35. Providing Portable Contracts The bundle exporting the package should do this: EExxppoorrtt-PPaacckkaaggee: javax.servlet;version=2.6, javax.servlet.http;version=2.6 PPrroovviiddee-CCaappaabbiilliittyy: osgi.contract; osgi.contract=JJaavvaaSSeerrvvlleett;version:VVeerrssiioonn=2.5; uses:="javax.servlet, javax.servlet.http", osgi.contract;osgi.contract=JJaavvaaSSeerrvvlleett;version:VVeerrssiioonn=3; uses:="javax.servlet, javax.servlet.http" as it only knows how the mapping is done. Each marketing version is mapped to a package version. For more details, see OSGi RFC 180 (https://github.com/osgi/design/raw/master /rfcs/rfc0180/rfc-0180-portable- java-contracts.pdf). 35 of 41
- 36. For all packages other than JCP-ones 36 of 41
- 37. http://www.bndtools.org (http://www.bndtools.org) can help with version maintenance! reallybndtools Use Semantic Versioning! 37 of 41
- 38. Where can I get it? Core R6 spec released this week: http://www.osgi.org/Specifications/HomePage (http://www.osgi.org/Specifications/HomePage) Enterprise R6 draft released this week: http://www.osgi.org/Specifications/Drafts (http://www.osgi.org/Specifications/Drafts) RFCs 189, 190, 208 included in zip 38 of 41
- 39. Links OSGi specs: http://www.osgi.org/Specifications (http://www.osgi.org/Specifications) Apache Felix Project: http://felix.apache.org (http://felix.apache.org) OSGi RFC 180 https://github.com/osgi/design/raw/master /rfcs/rfc0180/rfc-0180-portable-java-contracts.pdf (https://github.com/osgi/design/raw/master /rfcs/rfc0180/rfc-0180-portable-java-contracts.pdf) devicemon project: https://github.com/bosschaert/devicemon (https://github.com/bosschaert/devicemon) Subsystem Gogo command https://github.com/bosschaert/coderthoughts39 of 41