---
title: "Apache Karaf 4.4: provisioning and operations"
chapter: "14"
---

# Apache Karaf 4.4: provisioning and operations

Apache Karaf is a managed OSGi runtime distribution. Version 4.4.11 is the
current stable release and its 4.4 line supports OSGi R8 and Java 11+.

## What Karaf adds

- local and SSH shell;
- features repositories and application provisioning;
- configuration in `etc/`;
- logging, audit, JAAS-based security facilities;
- hot deployment;
- instance and wrapper tooling;
- integration with Pax Web, Aries, CXF, Camel, Decanter, and Cellar.

## Features

A feature is a named, versioned provisioning recipe listing bundles, configs,
libraries, requirements, and dependent features.

```xml
<feature name="charging-api" version="1.4.0">
  <feature>scr</feature>
  <bundle>mvn:com.acme/charging-api/1.4.0</bundle>
  <bundle>mvn:com.acme/charging-core/1.4.0</bundle>
</feature>
```

Feature resolution selects a compatible closure. Pin repositories and feature
versions. Test installation from an empty Karaf, not a developer cache.

## KAR and deploy directory

A KAR packages a features repository and artifacts for offline deployment.
The `deploy/` directory is convenient but implicit watching can surprise
production operations. Prefer an explicit, audited provisioning path.

## Shell diagnostics

Start with:

```text
bundle:list
bundle:diag <id>
headers <id>
services
scr:list
scr:info <component>
config:list
feature:list -i
log:tail
```

## Upgrades

Treat Karaf, framework, Pax Web, logging, features, Java, and applications as
one tested compatibility set. Use immutable base distributions and externalized
state. Rehearse config migration, data compatibility, feature rollback, and
clean-cache recovery.

## Security

Restrict SSH and JMX, rotate credentials and host keys, audit commands, limit
Web Console, protect `etc/`, verify artifacts and signatures, and isolate
management from public application traffic.

## Feynman check

Karaf is not a different module standard. It is an operator-friendly house
built around an OSGi framework and selected service implementations.