Repository Import

The Repository - Import external files task will take content from a directory on the server and import it into the desired repository in Nexus Repository. This will allow you to get external content into a repository from any source, even Nexus Repository 2.

Planning and Requirements

Before using this task, you should consider a few things:

• Space Requirements - Copying all components will double the assets and space on disk; hard linking does not do this but will take additional space to store all of the metadata.
• Location Requirements - The source directory must be writable by the user running Nexus Repository 3.  The import history is stored in the source directory to enable incremental imports.
• Timing - This task can take some time to run, and multiple imports are not done in parallel. Each task will need to complete before the next one will run.
• Frequency - You can configure this task to run manually or on a schedule depending on your needs.
• Performance - We do not recommend that you import directly to object storage such as S3 as doing so can result in poor performance.
• Deployment Policy Impacts for Hosted Repositories - If your hosted repository's deployment policy is set to Disable Redeploy, this will prevent overwriting and updating existing assets during import. See the "Hosted" sub-section of Managing Repositories and Repository Groups for more information on deployment policies.
• Limitations
  • Import is limited to just artifacts and their metadata; it does not include any other server configurations.
  • This task will also not import hidden files and directories (e.g., having names that start with a period).
• Hard Link Requirements 
  • To use hard links, the target repository blob store must be on the same file system as the source.
  • Hard linking is not supported for object storage blob stores.

Configuration

Create a new Repository - Import external files task and you will be presented with the configuration options listed below:

Important import-specific fields are as follows:

Target repository - The repository into which to import content. This list will only be populated with Hosted repositories of the supported Formats (see format list below).

Source directory - The directory from which to import content. 

Enable Hard Links - For some formats (see Hard Link Support in table below), enabling this option will create hard links for the blobs in the source directory to be used in the target directory. A physical copy of the blobs will not be created in the target directory. This can save time if the source directory will continue to be accessible by the current instance. Ensure you have read the hard link requirements under Planning and Requirements.

Running the Task

When the task runs, it generates a .nexus/nxrm-export-import-task/ directory inside of the source directory. This .nexus/nxrm-export-import-task/ directory contains metadata that Nexus Repository uses for future imports so that it will not import content multiple times if the task is run more than once. This will allow you to keep placing content into this directory while only importing newer content if you run the task again.

As Nexus Repository processes the import, it will log every single file it imports to the task log; a new task log is created each time a task runs. If an error occurs with any particular file, Nexus Repository will simply log that fact, then continue importing the rest of the content.

Resetting Data (.dat) Files

If you need to reset the import data files, run the following command:

rm .nexus/nxrm-import-task

Deleting Import Task Source Cache Files Inside Nexus Repository 2 Repository Storage Directory

Should you need to reset an import, you will need to delete the cache.

The following steps provide a workaround for deleting .dat files inside a Nexus Repository 2 storage directory where the .dat files are stored in a .nexus directory instead of .nexus/nxrm-export-import-task/:

1. Locate the source .nexus directory of the import
   1. In Nexus Repository 2, the default location would be sonatype-work/nexus/storage/<repoid>/.nexus
2. Use a command like the following to find and delete all the import cache files:

find sonatype-work/nexus/storage/releases/.nexus -type f -name 'imported-files*.dat' -delete

Supported Formats

You can import content into repositories of any format listed below. Some formats require that content be structured in a certain manner: