DSpace Statistics API

A simple REST API to expose Solr view and download statistics for items in a DSpace repository. This project contains a standalone indexing component and a WSGI application.

Requirements

• Python 3.5+
• PostgreSQL version 9.5+ (due to UPSERT support)
• DSpace 4+ with Solr usage statistics enabled

Installation and Testing

Create a Python virtual environment and install the dependencies:

$ python -m venv venv
$ . venv/bin/activate
$ pip install -r requirements.txt

Set up the environment variables for Solr and PostgreSQL:

$ export SOLR_SERVER=http://localhost:8080/solr
$ export DATABASE_NAME=dspacestatistics
$ export DATABASE_USER=dspacestatistics
$ export DATABASE_PASS=dspacestatistics
$ export DATABASE_HOST=localhost

Index the Solr statistics core to populate the PostgreSQL database:

$ ./indexer.py

Run the REST API:

$ gunicorn app:api

Test to see if there are any statistics:

$ curl 'http://localhost:8000/items?limit=1'

Deployment

There are example systemd service and timer units in the contrib directory. The API service listens on localhost by default so you will need to expose it publicly using a web server like nginx.

An example nginx configuration is:

server {
    #...

    location ~ /rest/statistics/?(.*) {
        access_log /var/log/nginx/statistics.log;
        proxy_pass http://statistics_api/$1$is_args$args;
    }
}

upstream statistics_api {
    server 127.0.0.1:5000;
}

This would expose the API at /rest/statistics.

Using the API

The API exposes the following endpoints:

• GET /items — return views and downloads for all items that Solr knows about¹. Accepts limit and page query parameters for pagination of results.
• GET /item/id — return views and downloads for a single item (id must be a positive integer). Returns HTTP 404 if an item id is not found.

¹ We are querying the Solr statistics core, which technically only knows about items that have either views or downloads.

Todo

• Add API documentation
• Close DB connection when gunicorn shuts down gracefully
• Better logging
• Tests
• Check if database exists (try/except)
• Version API
• Use JSON in PostgreSQL
• Switch to Python 3.6+ f-string syntax

License

This work is licensed under the GPLv3.