+1 Erwin
> On Sep 13, 2021, at 09:42, Achim Nierbeck <bcanh...@googlemail.com.INVALID> > wrote: > > Big Kudos to Grzegorz for not giving up on this in the last two years! > > best regards, Achim > > > Am Mo., 13. Sept. 2021 um 12:27 Uhr schrieb Grzegorz Grzybek < > gr.grzy...@gmail.com>: > >> Hello! >> >> After almost 2 years of refactoring and development, I think Pax Web 8 is >> ready for release. >> Manual updates are still on my list and some exhaustive documentation (and >> maybe a blog post) is being prepared... >> >> TL;DR: >> >> - `mvn clean install -DskipTests` in `main` branch of >>> https://github.com/ops4j/org.ops4j.pax.web >>> - start with clean Karaf 4.3.3 >>> >>> karaf@root()> repo-remove org.ops4j.pax.web-7.3.19 >>> karaf@root()> repo-add >>> mvn:org.ops4j.pax.web/pax-web-features/8.0.0-SNAPSHOT/xml/features >>> karaf@root()> feature:install pax-web-http-tomcat >>> karaf@root()> feature:install pax-web-war >>> karaf@root()> bundle:install -s >>> 'webbundle:mvn:io.hawt/hawtio-war/2.13.6/war?Web-ContextPath=/hawtio' >>> >>> - browse to http://localhost:8181/hawtio >>> >> >> However I think it'd be good to describe the rationale behind the rewrite >> and some key points of the new release. >> >> *Background information:* >> >> My single, initial reason to start the refactoring was >> https://github.com/ops4j/org.ops4j.pax.web/issues/1413 issue (migrated >> from https://ops4j1.jira.com/browse/PAXWEB-1123): "HTTP Whiteboard and >> selection of the ServletContextHelper". >> >> Whiteboard specification says, that every web element may reference a >> target ServletContextHelper using "osgi.http.whiteboard.context.select" >> service registration property and its value is an LDAP filter, which may >> also be: >> >> osgi.http.whiteboard.context.select=(osgi.http.whiteboard.context.name=*) >> >> which means "register the servlet into ALL available >> ServletContextHelpers". >> Pax Web 7 was taking the osgi.http.whiteboard.context.select property >> value and was doing split("=") on it to get the name/id of the target >> context... Effectively 1:1 relation was assumed, while Whiteboard >> specification assumes 1:N relationship. >> >> So I started to rewrite the internal Pax Web model... And somehow much >> much more was refactored. >> >> *Pax Web 8 goals:* >> >> - I've carefully read chapters 102 (Http Service specification), 128 >> (Web Applications specification) and 140 (Whiteboard specification) of OSGi >> CMPN R7 and tried to implement everything in best possible way >> - I always appreciated how well and cleverly Pax Web was written by >> others from this list: >> >> 11:41 $ git shortlog -snc origin/pax-web-7.2.x >>> 894 adreghi...@gmail.com >>> 747 anierbeck >>> 284 Achim Nierbeck >>> 182 ANierbeck >>> 123 Guillaume Nodet >>> 114 Jean-Baptiste Onofré >>> 103 Marc Schlegel >>> 77 jbonofre >>> 53 lostiniceland >>> 44 Stephan Siano >>> 37 Harald Wellmann >>> 21 Marc Klinger >>> 20 Freeman Fang >>> ... >>> >> >> - I wanted to keep the "spirit" of Pax Web - emphasizing target >> runtime (Jetty, Tomcat, Undertow) over "specification first" approach >> - I wanted to ensure that everything in Pax Web works as similar as >> possible in all 3 supported runtimes >> - I wanted to keep the possibility to use native container >> configuration (jetty.xml, tomcat-server.xml, undertow.xml) in addition to >> what we can pass through org.ops4j.pax.web PID >> - I wanted to make Pax Web 8 more reliable (no more flaky tests, no >> more random Thread.sleep() in tests, ...) >> >> *Pax Web 8 highlights:* >> >> - Latest versions of Jetty 9.4.x, Tomcat 9.0.x (without TIPI!) and >> Undertow 2.2.x are used >> - Web "elements" mentioned in Http Service and Whiteboard >> specifications are handled: servlets, filters, listeners, error pages >> - additionally, Pax Web 8 supports everything that can be configured >> in web.xml besides: <env-entry>, <post-construct>, <pre-destroy>, >> <resource-env-ref>, <resource-ref>, <administered-object>, >> <connection-factory>, <data-source>, <default-context-path>, <description>, >> <ejb-local-ref>, <ejb-ref>, <icon>, <jms-connection-factory>, >> <jms-destination>, <mail-session>, <message-destination>, >> <message-destination-ref>, <module-name>, <persistence-context-ref>, >> <persistence-unit-ref>, <service-ref> >> - "above" what we can find in web.xml, Pax Web 8 supports: >> - ServletContainerInitializers (SCI) - proved by working >> JSF/Primefaces/Vaadin examples >> - web-fragment.xmls >> - annotated web elements (@WebServlet, @WebFilter, @WebListener) >> - META-INF/resources locations >> - websockets via HttpService and Whiteboard >> - web fragment scanning using tomcat-util-scanner >> - without any mention in any CMPN specification, JSPs, welcome-pages, >> security configurations are supported >> - no more xbean used to scan the "class space" >> - no more dependency to ASM >> - single configuration thread that operates on global model and >> synchronizes the model changes with the state of target runtime (Jetty, >> Tomcat, Undertow) >> - consistent structure of pax-web-jetty, pax-web-tomcat and >> pax-web-undertow: >> - there's single >> org.ops4j.pax.web.service.<runtime>.internal.<Runtime>ServerController >> class (per runtime) implementing >> org.ops4j.pax.web.service.spi.ServerController#sendBatch() method >> - org.ops4j.pax.web.service.spi.task.Batch is a sequence of >> "operations" that change the model or affect the runtime >> - there's single >> org.ops4j.pax.web.service.<runtime>.internal.<Runtime>ServerWrapper >> class >> (per runtime) that: >> - keeps an instance of the "server" >> (org.eclipse.jetty.server.Server, >> org.apache.catalina.core.StandardServer >> or io.undertow.server.HttpHandler + collection of >> org.xnio.channels.AcceptingChannels) - Pax Web 8 DOESN'T use >> easy-to-use >> io.undertow.Undertow class! >> - implements org.ops4j.pax.web.service.spi.task.BatchVisitor >> interface that's used to react to state-changing operations (like >> registration of a servlet) - mind that a "batch" may be >> "transactional" >> - each runtime bundle contains some overriden runtime classes (like >> org.ops4j.pax.web.service.jetty.internal.PaxWebFilterHolder that extends >> org.eclipse.jetty.servlet.FilterHolder) >> - Knowing that we have 3 "ways into" the Pax Web (HttpService, >> Whiteboard, WABs), Pax Web 8 introduces the concept of "the view of the >> WebContainer" - each "way" uses specific "view" to interact with Pax Web >> runtime >> - The model is greatly simplified comparing to Pax Web 7: >> - there exist "model" classes (like >> org.ops4j.pax.web.service.spi.model.elements.ServletModel) which are >> held >> internall and passed around between whiteboard, war, runtime and target >> container bundles >> - from Whiteboard perspective, the "incoming" services, like >> "javax.servlet.Servlet" or >> "org.osgi.service.http.context.ServletContextHelper" are "tracked into" >> the >> model classes, so whether the servlet is registered by HttpService, >> Whiteboard or through a WAB, its processing is consistent and there's no >> problem mixing WABs, Whiteboard and HttpService approaches >> - the "model" classes are divided into "web elements" and "web >> contexts" and each "web element" may reference one or many "web >> contexts" >> and the relation is dynamic >> - ... >> >> *Pax Web 8 example:* >> >> The most important use-case is: >> >> - user/bundle registers (Whiteboard approach) a servlet without >> specifying a "context" and the servlet has mapping "/my-servlet" >> - this servlet should be available at URL >> http://localhost:8181/my-servlet >> - another user/bundle registers a >> org.osgi.service.http.context.ServletContextHelper service with >> "osgi.http.whiteboard.context.path=/my-context" and " >> osgi.http.whiteboard.context.name=default" properties >> - *immediately* (asap) the first servlet should be available at >> http://localhost:8181/my-context/my-servlet and *no longer* it should >> be available at the first URL >> >> Yes, it works. Also shadowing may happen, because when two servlets are >> registered with the same name and target context, only the one with higher >> ranking/lower service.id should be available. There are many integration >> tests that show what happens when conflicting services are registered >> across different contexts. >> >> *Summary*: >> >> If you have some time, please checkout >> https://github.com/ops4j/org.ops4j.pax.web/tree/main, `mvn clean >> -DskipTests` it and give it a try. >> >> For example in Karaf 4.3.3 (after uncommenting "karaf" user in >> `etc/users.properties`) we can do: >> >> karaf@root()> repo-remove org.ops4j.pax.web-7.3.19 >>> Removing features repository: >>> mvn:org.ops4j.pax.web/pax-web-features/7.3.19/xml/features >>> karaf@root()> repo-add >>> mvn:org.ops4j.pax.web/pax-web-features/8.0.0-SNAPSHOT/xml/features >>> Adding feature url >>> mvn:org.ops4j.pax.web/pax-web-features/8.0.0-SNAPSHOT/xml/features >>> karaf@root()> feature:install pax-web-http-tomcat >>> karaf@root()> feature:install pax-web-war >>> karaf@root()> bundle:install >>> 'webbundle:mvn:io.hawt/hawtio-war/2.13.6/war?Web-ContextPath=/hawtio' >>> Bundle ID: 68 >>> karaf@root()> start 68 >>> >> >> Then you can log in to http://localhost:8181/hawtio using karaf/karaf >> credentials (JAAS based authentication) and then navigate to >> http://localhost:8181/hawtio/jmx/attributes?nid=root-Catalina-WebResourceRoot-localhost-%2FServletContextModel-3-Cache >> which shows cache configuration for the default (resource) servlet used by >> /hawtio WAB. >> >> kind regards and thanks for the patience ;) >> Grzegorz Grzybek >> >> -- >> -- >> ------------------ >> OPS4J - http://www.ops4j.org - op...@googlegroups.com >> >> --- >> You received this message because you are subscribed to the Google Groups >> "OPS4J" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to ops4j+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/ops4j/CAAdXmhpRUK%2B-0fSYnXMXUevpfuDDLgSqhLXdq83Tae3c6usnCQ%40mail.gmail.com >> <https://groups.google.com/d/msgid/ops4j/CAAdXmhpRUK%2B-0fSYnXMXUevpfuDDLgSqhLXdq83Tae3c6usnCQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > > Apache Member > Apache Karaf <http://karaf.apache.org/> Committer & PMC > OPS4J Pax Web <http://wiki.ops4j.org/display/paxweb/Pax+Web/> Committer & > Project Lead > blog <http://notizblog.nierbeck.de/> > Co-Author of Apache Karaf Cookbook <http://bit.ly/1ps9rkS>
