Apache Maven MarsJUG. Arnaud Héritier exo platform Software Factory Manager

Transcription

1 Apache Maven MarsJUG Arnaud Héritier exo platform Software Factory Manager

2 Software Factory Manager at exo platform In charge of tools and methods Arnaud Héritier Committer since 2004 and member of the Project Management Committee Coauthor of «Apache Maven» published by Pearson (in French)

3 Apache Maven OVERVIEW

4 Apache Maven BASICS 4

5 Definition Apache Maven is a software project management and comprehension tool. Based on the concept of a project object model (POM), Maven can manage a project's build, binaries, reporting and documentation from a central piece of information. Apache Maven is a command line tool with some IDE integrations.

6 Conventions 1 project = 1 artifact (pom, jar, war, ear, ) Standardized directories layout project descriptor (POM) build lifecycle 6

7 POM An XML file (pom.xml) Describing Project identification Project version Project description Build settings Dependencies <?xml version="1.0" encoding="utf-8"?> <project> <modelversion>4.0.0</modelversion> <groupid>org.apache.maven</groupid> <artifactid>webapp-sample</artifactid> <version>1.1-snapshot</version> <packaging>war</packaging> <name>simple webapp</name> <inceptionyear>2007</inceptionyear> <dependencies> <dependency> <groupid>org.springframework</groupid> <artifactid>spring-struts</artifactid> <version>2.0.2</version> </dependency>... </dependencies> </project>

8 Dependencies Without Maven With Maven

9 Declaratives Dependencies groupid + artifactid + version (+ classifier) Type (packaging) : jar, war, pom, ear, Transitives Lib A needs Lib B Lib B needs Lib C Thus Lib A needs Lib C

10 Scope Dependencies Compile (by default) : Required to build and run the application Runtime : not required to build the application but needed at runtime Ex : taglibs Provided : required to build the application but not needed at runtime (provided by the container) Ex : Servlet API, Driver SGBD, Test : required to build and launch tests but not needed by the application itself to build and run Ex : Junit, TestNG, DbUnit, System : local library with absolute path Ex : software products

11 Artifact Repository By default : A central repository 2 Several dozen of Gb of OSS libraries A local repository ${user.home}/.m2/repository All artifacts Used by maven and its plugins Used by your projects (dependencies) Produced by your projects

12 Artifact Repository By default Maven downloads artifacts required by the project or itself from central Downloaded artifacts are stored in the local repository

13 Versions Project and dependency versions Two different version variants SNAPSHOT version The version number ends with SNAPSHOT The project is in development Deliveries are changing over the time and are overridden after each build Artifacts are deployed with a timestamp on remote repositories RELEASE version The version number doesn t end with SNAPSHOT Binaries won t change

14 Versions

15 Versions About SNAPSHOT dependencies Maven allows the configuration of an update policy. The update policy defines the recurrence of checks if there is a new SNAPSHOT version available on the remote repository : always daily (by default) interval:x (a given period in minutes) never Must not be used in a released project They can change thus the release also

16 Versions Range From to Maven automatically searches for the corresponding version (using the update policy for released artifacts) To use with caution Risk of non reproducibility of the build Risk of side effects on projects depending on yours.

17 Reactor Ability of Maven to build several sub-modules resolving the order of their dependencies Modules have to be defined in the POM For a performance reasons pom.xml : <modules> <module>modulea</module> <module>modulec</module> <module>moduleb</module> </modules>

18 Inheritence Share settings between projects/modules Project Business1 Jar War Business2 Jar War By default the parent project is supposed to be in the parent directory (../) pom.xml for module Jar1 <parent> <groupid>x.y.z</groupid> <artifactid>jars</artifactid> <version>1.0-snapshot<version> </parent>

19 Build Lifecycle And Plugins Plugin based architecture for a great extensibility Standardized lifecycle to build all types of archetypes

20 Apache Maven WHY DOES A PROJECT CHOOSE MAVEN?

21 Maven, the project s choice Application s architecture The project has the freedom to divide the application in modules Maven doesn t limit the evolution of the application architecture Dependencies management Declarative : Maven automatically downloads them and builds the classpath Transitive : We define only what the module needs itself

22 Maven, the project s choice Centralizes and automates all development facets (build, tests, releases) One thing it cannot do for you : to develop Builds Tests Packages Deploys Documents Checks and reports about the quality of developments

23 Apache Maven WHY DOES A COMPANY CHOOSE MAVEN?

24 Maven, the corporate s choice Widely adopted and known Many developers Developments are standardized Decrease of costs Reuse of knowledge Reuse of configuration fragments Reuse of process and code fragments Product quality improvement Reports and monitoring

25 Apache Maven ECOSYSTEM

26 Maven alone is nothing Maven s ecosytem You can integrate it with many tools

27 Apache Maven REPOSITORY MANAGERS

28 Repository Managers Several products Sonatype Nexus (replaced Proximity) Jfrog Artifactory Apache Archiva Basic services Search artifacts Browse repositories Proxy external repositories Host internal repositories Security

29 Secure your builds Deploy a repository manager to proxy externals repositories to : Avoid external network outages Avoid external repository unavailabilities To reduce your company s external network usage To increase the speed of artifact downloads Additional services offered by such servers : Artifacts procurement to filter what is coming from the outside Staging repository to validate your release before deploying it

30 Setup a global mirror <settings> <mirrors> <mirror> <!--This sends everything else to /public --> <id>global-mirror</id> <mirrorof>external:*</mirrorof> <url> </mirror> </mirrors> <profiles> <profile> <id>mirror</id> <!--Enable snapshots for the built in central repo to direct --> <!--all requests to the repository manager via the mirror --> <repositories> <repository> <id>central</id> <url> <releases><enabled>true</enabled></releases> <snapshots><enabled>true</enabled></snapshots> </repository> </repositories> <pluginrepositories> <pluginrepository> <id>central</id> <url> <releases><enabled>true</enabled></releases> <snapshots><enabled>true</enabled></snapshots> </pluginrepository> </pluginrepositories> </profile> </profiles> <activeprofiles> <!--make the profile active all the time --> <activeprofile>mirror</activeprofile> </activeprofiles> </settings>

31 Apache Maven QUALITY MANAGEMENT

32 Automate tests Use automated tests as often as you can Many tools are available through Maven JUnit, TestNG unit tests, Selenium, Canoo web GUI test, Fitnesse, Greenpepper functional tests, SoapUI web services tests JMeter performances tests And many more frameworks are available to reply your needs

33 Quality Metrics Extract quality metrics from your project and monitor them : Code style (CheckStyle) Bad practices or potential bugs (PMD, FindBugs, Clirr) Tests coverage (Cobertura, Emma, Clover) You can use blocking rules For example, I break the build if the upward compatibility of public APIs is broken You can use reports Reports are available in a web site generated by Maven Or in a quality dashboard like Sonar

34 Dependency Report

35 Sonar Dashboard

36 Apache Maven CONTINUOUS INTEGRATION

37 Continuous Integration Setup a continuous integration server to : Have a neutral and unmodified environment to run your tests Quickly react when The build fails (compilation failure for example) A test fails A quality metric is bad Continuously improve the quality of your project and your productivity Many products Hudson, Bamboo, TeamCity, Continuum, Cruisecontrol,

38 Hudson

39 Apache Maven GOOD & BAD PRACTICES

40 Apache Maven KISS

41 Keep It Simple, Stupid Start from scratch K.I.S.S. Do not copy/paste what you find without understanding Use only what you need It s not because maven offers many features that you need to use them Filtering Modules Profiles

42 Apache Maven PROJECT ORGANIZATION GOOD & BAD PRACTICES

43 Project bad practices Ignore Maven conventions Except if your are migrating from something else and the target has to be to follow them. Except if they are not compatible with your IDE Different versions in sub-modules In that case they are standalone projects. Too many inheritance levels It makes the POMs maintenance more complex Where should I set this plugin parameter? In which parent?

44 Project bad practices Have too many modules Is there a good reason? Technical constraint? Team organization? It increases the build time Many more artifacts to generate Dependencies resolution more complex It involves more complex developments More modules to import in your IDE More modules to update

45 Project good practices Use the default inheritance : The reactor project is also the parent of its modules. Configuration is easier : No need to redefine SCM settings, site distribution settings

46 Apache Maven POM GOOD & BAD PRACTICES

47 Dependencies : POM bad practices DON T confuse dependencies and dependencymanagement Plugins : DON T confuse plugins and pluginmanagement DON T use AntRun plugin everywhere DON T let Maven choose plugins versions for you

48 POM bad practices Profiles : DON T create environment dependant builds DON T rely on dependencies coming from profiles (there is no transitive activation of profiles) Reporting and quality DON T activate on an existing project all reports with default configuration DON T control formatting rules without giving settings for IDEs. DON T put everything you find in your POM.

49 POM good practices Set versions of dependencies in project parent s dependencymanagement Set dependencies (groupid, artifactid, scope) in each module they are used Use the dependency plugin (from apache) and versions plugin (from mojo) to analyze, cleanup and update your dependencies.

50 Apache Maven DEVELOPMENT GOOD & BAD PRACTICES

51 Development bad practices DON T spend your time in the terminal, DON T exchange libraries through s, DON T always use "-Dmaven.test.skip=true DON T manually do releases

52 Development good practices Keep up-to-date your version of Maven For example in 2.1 the time of dependencies/modules resolution decreased a lot (Initialization of a project of 150 modules passed from 8 minutes to less than 1) Use the reactor plugin (Maven < 2.1) or native reactor command line options (Maven >= 2.1) to rebuild only a subpart of your project : All modules depending on module XXX All modules used to build XXX Try to not use Maven features not supported by your IDE (resources filtering with the plugin eclipse:eclipse)

53 Apache Maven USECASES

54 Apache Maven SECURE YOUR CREDENTIALS

55 Secure your credentials Generate a private key arnaud@leopard:~$ mvn --encrypt-master-password toto {dzpuz74ytj0hnwhgm4zgfdlruyqnda1xib9vavf2vvy=} We save the private key in ~/.m2/settings-security.xml <settingssecurity> <master>{dzpuz74ytj0hnwhgm4zgfdlruyqnda1xib9vavf2vvy=}</master> </settingssecurity>

56 Secure your credentials You can move this key to another drive ~/.m2/settings.xml <settingssecurity> <relocation>/volumes/arnaudusbkey/secure/settings-security.xml</relocation> </settingssecurity> You create an encrypted version of your server password mvn --encrypt-password titi{sbc9fl2ja4ohztz5fcefp2q1tmxetbkz9qikljpihss=} You register it in your settings <settings>... <servers>... <server> <id>mon.server</id> <username>arnaud</username> <password>{sbc9fl2ja4ohztz5fcefp2q1tmxetbkz9qikljpihss=}</password> </server>... </servers>... </settings>

57 Apache Maven BUILD A PART OF YOUR PROJECT

58 Reactor options (Maven > 2.1)

59 Apache Maven RELEASE YOUR PROJECT

60 Release of a webapp in 2002 Limited usage of eclipse No WTP (Only some features in WSAD), No ability to produce WARs

61 Release of a webapp in 2002 Many manual tasks Modify settings files Package JARs Copy libraries (external and internal) in a «lib» directory Package WAR (often with a zip command) Tag the code (CVS) Send the package on the integration server using FTP Deploy the package with AS console

62 Release of a webapp in 2002 One problem : The are always problems Error in config files Missing dependencies Missing file Last minute fix which created a bug How long did it take? When everything is ok : 15 minutes When there s a problem : ½ day or more And many other possibilies..

63 Maven Release Plugin Automates the release process from tagging sources to binaries delivery Release plugin main goals: Prepare : To update maven versions and information in POMs and tag the code Perform : To deploy binaries in a maven repository After that you can just automate the deployment on the AS using cargo for example.

64 Maven Release Plugin

65 Configuration and Prerequisites Project version (must be a SNAPSHOT version) Dependencies and plugins versions mustn t be SNAPSHOTs

66 SCM configuration SCM binaries have to be in the PATH SCM credentials have to already be stored or you have to pass them in command line with : Dusername=XXX Dpassword=XXX <scm> <connection> scm:svn: </connection> <developerconnection> scm:svn: </developerconnection> <url> </url> </scm>

67 Distribution Management <project> <distributionmanagement> <repository> <id>repository.exoplatform.org</id> <url>${exo.releases.repo.url}</url> </repository>... </distributionmanagement>... <properties> <exo.releases.repo.url> </exo.releases.repo.url>... </properties> </project>

68 Repository credentials <settings> <servers> <server> <! - id must be the one used in distributionmanagement --> <id>repository.exoplatform.org</id> <username>aheritier</username> <password>{abcdefghijklmnopqrstuvwyz}</password> </server> </servers> </settings>

69 Default Release Profile in Super POM <profile> <id>release-profile</id> <activation> <property> <name>performrelease</name> <value>true</value> </property> </activation> <build> <plugins> <! - Configuration to generate sources and javadoc jars -->... </plugins> </build> </profile>

70 Custom release profile <project>... <build> <pluginmanagement> <plugins> <plugin> <groupid>org.apache.maven.plugins</groupid> <artifactid>maven-release-plugin</artifactid> <version>2.0-beta-9</version> <configuration> <usereleaseprofile>false</usereleaseprofile> <arguments>-pmyreleaseprofile</arguments>... <profiles> <profile> <id>myreleaseprofile</id> <build> <!- what you want to customize the behavior of the build when you do a release --> </build> </profile> </profiles>... </project> </configuration> </plugin> </plugins> </pluginmanagement> </build>

71 Troubleshooting Releases Common errors during release: Build with release profile was tested before and fails Local modifications Current version is not a SNAPSHOT SNAPSHOTs in dependencies and/or plugins Missing some configuration (scm, distribmgt, ) Tag already exists Unable to deploy project to the Repository Connection problems

72 Apache Maven TO GO FURTHER

73 Apache Maven DOCUMENTATIONS

74 The main web site : Project s team wiki : Some links Project s users wiki :

75 Books Sonatype / O Reilly : The Definitive Guide oks Free download Available in several languages Soon in French

76 Books Exist Global Better builds with Maven better-build-maven Free download

77 Books Nicolas De loof Arnaud Héritier Published by Pearson Collection Référence Based on our own experiences with Maven. From beginners to experts. In French only Available on 20th November

78 Apache Maven SUPPORT

79 Support Mailing lists IRC irc.codehaus.org - #maven Forums forum maven In French Dedicated support Sonatype and some others companies

80 Apache Maven BACK TO THE FUTURE

81 Apache Maven PRODUCT

82 Apache Maven 2.0.x bugs fix Last release : No planned

83 Apache Maven 2.x Evolutions, new features Several important new features in 2.1 like Parallel downloads Encrypted passwords Last release : in few months, 2.3 in 2010

84 Do not be afraid!!!!! Not final before at least one year Full compatibility with maven 2.x projects Apache Maven 3.x

85 What s new : Apache Maven 3.x How POMs are constructed How the lifecycle is executed How the plugin manager executes How artifacts are resolved How it can be embedded How dependency injection is done

86 Apache Maven 3.x What it will change for maven users? Any-source POM Versionless parent elements Mixins : a compositional form of Maven POM configuration Better IDE integration Error & integrity reporting Much improved error reporting where we will provide links to each identifiable problem we know of. There are currently 42 common things that can go wrong. Don't allow builds where versions come from non-project sources like local settings and CLI parameters Don't allow builds where versions come from profiles that have to be activated manually

87 Apache Maven 3.x What it will change for maven developers? Lifecycle extension points Plugin extension points Incremental build support Queryable lifecycle Extensible reporting

88 Apache Maven COMMUNITY

89 1780 subscribers on users mailing list Users community 90 days statistics Number of subscribers in blue Number of messages per day in red

90 The web site

91 Dowloads Per month downloads

92 The team 60 committers, More than 30 active since the beginning of the year, Several organizations like Sonatype, deliver resources and professional support, A community less isolated : more interactions with Eclipse, Jetty,

93 Commit Statistics

94 Apache Maven COMPETITORS

95 Competitors Ant + Ivy, Easy Ant, Gant, Graddle, Buildr Script oriented You can do what you want! Reuse many of Maven conventions (directories layout, ) and services (repositories) but without enforcing them The risk for them : Not being able to evolve due to the too high level of customization proposed to the user. We tried on Maven 1 and it died because of that. It s like providing a framework without public API.

96 Apache Maven CONCLUSION

97 Conclusion Today, Maven is widely adopted in corporate environments, It provides many services, It has an important and really active community of users and developers Many resources to learn to use it and a professional support are available A product probably far from being perfect but on rails for the future Many things to do We need you!

98 Apache Maven QUESTIONS?

99 Licence et copyrights Photos and logos belong to their respective authors/owners Content under Creative Commons 3.0 Attribution You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Noncommercial You may not use this work for commercial purposes. Share Alike If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.