Nexus and Maven build

Question

I've installed and configured Nexus3. It's behind a proxy and the HTTP section was configured.

[UPDATED AFTER FIRST COMMENTS]

On my settings.xml

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                      http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <localRepository/>
  <interactiveMode/>
  <usePluginRegistry/>
  <offline/>
  <pluginGroups/>
  <servers/>
  <proxies/>
  <mirrors>
    <mirror>
      <id>nexus</id>
      <mirrorOf>*</mirrorOf>
      <url>http://nexus.company.it:8081/repository/maven-central/</url>
    </mirror>
  </mirrors> 
</settings>

When I try to run mvn clean I get

 [INFO] Scanning for projects...
 [INFO]                                                                         
 [INFO] ------------------------------------------------------------------------
 [INFO] Building xxxx Maven Webapp 0.0.1-SNAPSHOT
 [INFO] ------------------------------------------------------------------------
 [WARNING] The POM for org.apache.maven.plugins:maven-clean-plugin:jar:2.5 is missing, no dependency information available
 [INFO] ------------------------------------------------------------------------
 [INFO] BUILD FAILURE
 [INFO] ------------------------------------------------------------------------
 [INFO] Total time: 0.205 s
 [INFO] Finished at: 2016-05-31T10:40:58+02:00
 [INFO] Final Memory: 13M/479M
 [INFO] ------------------------------------------------------------------------
 [ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved: Failure to find org.apache.maven.plugins:maven-clean-plugin:jar:2.5 in http://nexus.company.it:8081/repository/maven-central/ was cached in the local repository, resolution will not be reattempted until the update interval of nexus has elapsed or updates are forced -> [Help 1]
 [ERROR] 
 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
 [ERROR] 
 [ERROR] For more information about the errors and possible solutions, please read the following articles:
 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResolutionException

If I browse http://nexus.company.it:8081/repository/maven-central/

 Nexus Repository Manager
 OSS 3.0.0-03    
 This maven2 proxy repository is not directly browseable at this URL.

If I browse http://nexus.company.it:8081/#browse/browse/components:maven-central , the repository is empty

Could someone help me to configure my nexus as proxy for maven central?

R

Answer 1

I found the solution, even if "mvn clean -U" still does not work. Maybe someone could point me to right solution

1) Plugins are not in maven-central. You should you maven-public which groups maven-central and maven-releases/snapshots

2) I disabled the Anonymous Login in Nexus3. So I needed to create an user for connecting to Nexus3. Here there is the final settings.xml

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                      http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <localRepository/>
  <interactiveMode/>
  <usePluginRegistry/>
  <offline/>
  <pluginGroups/>
  <profiles/>
  <proxies>
      <proxy>
        <active>true</active>
        <protocol>http</protocol>
        <host>XXX.XXX.XXX.XXX</host>
        <port>XXX</port>
        <nonProxyHosts>XXX.XXX.*|*localhost*|*.company.it*</nonProxyHosts>
      </proxy>
  </proxies>
  <servers>
     <server>
       <id>nexus</id>
       <username>XXXXXXXXXX</username>
       <password>XXXXXXXXXX</password>
     </server>
  </servers>
  <mirrors>
    <mirror>
      <id>nexus</id>
      <mirrorOf>*</mirrorOf>
      <url>http://nexus.company.it:8081/repository/maven-public/</url>
    </mirror>
  </mirrors> 
  <activeProfiles/>
</settings>

3) Add -U option when you user mvn

Riccardo