2. Installation

2.1. Prerequisites

Component	Notes
Java 21 (JRE or JDK)	The application is a single executable jar.
PostgreSQL	Primary data store (APUs, imported packages, import journal).
Elasticsearch (optional)	Default search engine. Deployments may instead run the embedded Lucene engine (`search.engine: lucene`), which needs no external search server; Elasticsearch remains the recommended production engine. No Elasticsearch analysis plugins are required — the index uses built-in analyzers only.

2.2. Artifact and layout

A deployment consists of one executable jar (aron.jar) containing the backend and the web UI, plus an external configuration directory:

/opt/aron/
  aron.jar
  config/
    application.yml        # main configuration (template ships with the sources)
    types.yaml             # display / indexing model of description items
    searchConfig.yaml      # facet (and search relevance) configuration
    pageTemplate.yaml      # portal name, localization, menu
    citation.yaml          # citation forms; citation.groovy beside it
    news.yaml
    favoriteQueries.yaml
    images/                # logo, top image

config/application.yml is resolved relative to the working directory; a template is provided at distribution/config/application.yml.template in the source tree.

2.3. Running

java -jar aron.jar

The application creates and migrates its database schema automatically (Liquibase) and bootstraps the search index at startup (see Operations).

2.4. URL layout

Path	Purpose
`/`	Public portal (single-page application).
`/api/v1/**`	Current REST API.
`/api/aron/**`	Legacy REST API (kept for compatibility, frozen).
`/actuator/**`	Spring Boot Actuator (health, metrics). Intentionally outside the `/api` namespace.
`/cxf/**`	Internal SOAP interfaces used by Transfagent: `/cxf/ft` for data ingest (file transfer) and `/cxf/management` for withdrawing data it has published. Never expose them publicly; they can also be moved to a separate port, see below.

2.5. Reverse proxy and subpath deployment

The same jar works at the URL root and under any subpath without rebuilding:

Standalone under a subpath: set server.servlet.context-path (for example /aron) in application.yml.
Behind a reverse proxy: forward the prefix in the X-Forwarded-Prefix header; the application folds it into the effective context path.

2.6. Separate port for the internal interfaces

By default the internal SOAP interfaces share the main server port and are kept private by the proxy rules below. A deployment can instead give them their own listener:

soap:
  port: 8081
  address: 10.0.0.5   # optional: bind to the internal interface only

The split is then strict: /cxf/** is served only on soap.port, and that port serves only /cxf/** — no portal, no REST API, no actuator. With soap.address the interfaces are not even reachable from the public network, so a mistake in the proxy configuration cannot expose them. Unset soap.port keeps the current behaviour, which is also what development uses.

The endpoints keep their paths — http://host:8081/cxf/ft and http://host:8081/cxf/management. The one exception is a standalone subpath deployment (server.servlet.context-path): the paths carry that prefix on every port, exactly as they do today on the main one (http://host:8081/aron/cxf/ft).

Proxy rules for a public deployment:

Block /cxf/** — these are service-to-service interfaces for Transfagent (ingest and data withdrawal), not part of the public API. With soap.port configured the proxy has nothing to block: the paths do not exist on the public port.
Decide explicitly whether /actuator/** is reachable from the outside; in most deployments it should be restricted to the monitoring network.