Repository Management with Nexus

3.11. Nexus Directories

The following sections describe the various directories that are a part of any Nexus installation. When you install Nexus Open Source or Nexus Professional, you are creating two directories: a directory containing the Nexus runtime and application often symlinked as nexus and a directory containing your own configuration and data - sonatype-work/nexus. When you upgrade to a newer version of Nexus, you replace the Nexus application directory and retain all of your own custom configuration and repository data in sonatype-work/.

3.11.1. Sonatype Work Directory

The Sonatype Work directory sonatype-work is created as a sibling to the nexus application directory, and the location of this directory can be configured via the nexus.properties file which is described in Section 3.11.2, “Nexus Configuration Directory”.

The Sonatype Work Nexus directory sonatype-work/nexus/ contains a number of subdirectories. Depending on the plugins installed and used, some directories may or may be not present in your installation:

access/
This directory contains a log of all IP addresses accessing Nexus. The data can be viewed by clicking on Active Users Report in the Administration - Licensing tab in the Nexus user interface.
aether-local-repository/ or maven2-local-repository
This holds temporary files created when running Maven dependency queries in the user interface.
backup/
If you have configured a scheduled job to back up Nexus configuration, this directory is going to contain a number of ZIP archives that contain snapshots of Nexus configuration. Each ZIP file contains the contents of the conf/ directory. (Automated backups are a feature of Nexus Professional.)
broker/
The broker directory and its subdirectories contains the storage backend for the Smart Proxy messaging component.
conf/
This directory contains the Nexus configuration. Settings that define the list of Nexus repositories, the logging configuration, the staging and procurement configuration, and the security settings are all captured in this directory.
conf/keystore/
Contains the automatically generated key used to identify this Nexus instance for Smart Proxy usage
db/
Contains the database storing the User Token information, if that feature is enabled.
error-report-bundles/
Used to contain the bundled archives of data assembled for problem reporting. Since this feature has been removed this folder can be safely deleted.
felix-cache/
This directory holds the cache for the OSGi framework Apache Felix, which is used for the Nexus plugin architecture.
health-check/
Holds cached reports from the Repository Health Check plugin.
indexer/ and indexer-pro/
Contains a Nexus index for all repositories and repository groups managed by Nexus. A Nexus index is a Lucene index which is the standard for indexing and searching a Maven repository. Nexus maintains a local index for all repositories, and can also download a Nexus index from remote repositories.
logs/
The nexus.log file that contains information about a running instance of Nexus. This directory also contains archived copies of Nexus log files. Nexus log files are rotated every day. To reclaim disk space, you can delete old log files from the logs directory.
nuget/
Contains the database supporting queries against NuGet repositories used for .NET package support in Nexus.
p2/
If you are using the P2 repository management features of Nexus Professional, this directory contains a local cache of P2 repository artifacts.
plugin-repository/
This directory contains any additionally installed plugins from third parties as documented in Section 22.1, “Managing Nexus Plugins”.
proxy/
Stores data about the files contained in a remote repository. Each proxy repository has a subdirectory in the proxy/attributes/ directory and every file that Nexus has interacted with in the remote repository has an XML file that captures the last requested time stamp, the remote URL for a particular file, the length of the file, the digests for a particular file, and others. If you need to backup the local cached contents of a proxy repository, you should also back up the contents of the proxy repository’s directory under proxy/attributes/
storage/
Stores artifacts and metadata for Nexus repositories. Each repository is a subdirectory that contains the artifacts in a repository. If the repository is a proxy repository, the storage directory will contain locally cached artifacts from the remote repository. If the repository is a hosted repository, the storage directory will contain all artifacts in the repository. If you need to back-up the contents of a repository, you should back up the contents of the storage directory.
support/
The support zip archive documented in Section 5.13, “Support Tools” is created and stored in this folder.
template-store/
Contains the Maven settings template files documented in detail in Chapter 13, Managing Maven Settings.
timeline/
Contains an index which Nexus uses to store events and other information to support internal operations. Nexus uses this index to store feeds and history.
tmp/
Folder used for temporary storage.
trash/
If you have configured scheduled jobs to remove snapshot artifacts or to delete other information from repositories, the deleted data will be stored in this directory. To empty this trash folder, view a list of Nexus repositories, and then click on the Trash icon in the Nexus user interface.

The conf/ directory contains a number of files which allow for configuration and customization of Nexus. All of the files contained in this directory are altered by the Nexus administrative user interface. While you can change the configuration settings contained in these files with a text editor, Sonatype recommends that you modify the contents of these files using the Nexus administrative user interface. Depending on your Nexus version and the installed plugins, the complete list of files may differ slightly.

broker.groovy
A groovy script for configuring low-level properties for Smart Proxy.
capabilities.xml
Further Smart Proxy backend configuration.
healthcheck.properties
Configuration for the Repository Health Check.
logback.properties, logback.xml and logback-*.xml
Contains logging configuration. If you need to customize the detail of log messages, the frequency of log file rotation, or if you want to connect your own custom logging appenders, you should edit the logback-nexus.xml configuration file as desired. If you find log4j.properties files as well, you can safely remove them since they are remnants from an old version and are not used anymore.
lvo-plugin.xml
Contains configuration for the latest version plugin. This XML file contains the location of the properties file that Nexus queries to check for a newer version of Nexus.
nexus.xml
The bulk of the configuration of Nexus is contained in this file. This file maintains a list of repositories and all server-wide configuration like the SMTP settings, security realms, repository groups, targets, path mappings and others.
pgp.xml
Contains PGP key server configuration.
nexus-obr-plugin.properties
Contains configuration for the Nexus OSGi Bundle repository plugin in Nexus Professional.
procurement.xml
Contains configuration for the Nexus Procurement plugin in Nexus Professional.
security-configuration.xml
Contains global security configuration.
security.xml
Contains security configuration about users and roles.
staging.xml
Contains configuration for the Nexus Staging Plugin in Nexus Professional.

3.11.2. Nexus Configuration Directory

After installing Nexus and creating the nexus symlink as described earlier, your fnexus folder contains another conf directory. This directory contains configuration for the Jetty servlet container. You will only need to modify the files in this directory if you are customizing the configuration of Jetty servlet container or the behavior of the scripts that start Nexus.

The files and folders contained in this directory are:

+ nexus.properties:: This file contains configuration variables which control the behavior of Nexus and the Jetty servlet container. If you are customizing the port and host that Nexus will listen to, you would change the application-port and application-host properties defined in this file. If you wanted to customize the location of the sonatype-work directory, you would modify the value of the nexus-work property in this configuration file. Changing nexus-webapp-context-path allows you to configure the server context path Nexus will be available at.

jetty.xml and jetty-*.xml

Configuration files for the Eclipse Jetty servlet container running Nexus. Jetty users are used to providing a list of jetty XML config files which are merged to form the final configuration. As an advanced configuration option, Nexus supports this merging concept in its launcher code as of Nexus 2.8.

You can specify additional jetty XML configuration files to load to form the final configuration. For the standard distribution bundle, these files can be specified using special properties located in NEXUS_HOME/bin/jsw/conf/wrapper.conf.

wrapper.app.parameter.1=./conf/jetty.xml
wrapper.app.parameter.2=./conf/jetty-requestlog.xml
# add more indexed app parameters...

Any of the files located at NEXUS_HOME/conf/jetty-*.xml can be specified as part of the wrapper.app.parameter.n property, where n is the next highest number not already used. The Java Service Wrapper documentation contains more information about this property. This setup allows for a simple method to add configuration for https, JMX and others by adjusting a few properties.

[Warning]

Nexus version prior to 2.8 loaded all of the Jetty configuration from one jetty.xml file, typically found at NEXUS_HOME/conf/jetty.xml and required modifications to this file for configuration changes. Examples were available in NEXUS_HOME/conf/examples. These files cannot be used in Nexus 2.8 or higher, as they were intended to be standalone files that could not be merged into other files.