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Installing on Apache Karaf

Red Hat Fuse 7.3

Installing Red Hat Fuse on the Apache Karaf container

Fuse Documentation Team


It is easy to install Red Hat Fuse and tailor the installation to a particular environment.


Red Hat Fuse is a lightweight, flexible integration platform that enables rapid integration across the extended enterprise—on-premise or in the cloud.

Based on Apache Camel, Fuse leverages pattern-based integration, a rich connector catalog, and extensive data transformation capabilities to enables users to integrate anything.

Chapter 1. Install Fuse for Development on Apache Karaf

To develop Fuse applications that run on Karaf, install Fuse locally as described in the following topics:

1.1. Prepare to install Fuse on Apache Karaf

To prepare to install Fuse on Apache Karaf, check your system to ensure that it meets hardware requirements, is a supported platform, and has a supported Java runtime. Also, confirm that you plan to use supported standard software for web services, APIs, and transport protocols.


  1. On the system on which you plan to install Fuse, confirm that it has:

    • 250 MB of free disk space
    • 2 GB of RAM

    This hardware requirement is for a full installation of Fuse on Apache Karaf. In addition, a system that is running Fuse requires space for caching, persistent message stores, and other functions. The actual requirement is dependent on what your Fuse applications do.

  2. Confirm that the system on which you plan to install Fuse is running a supported platform. Red Hat tests and supports Fuse products on the platforms that are listed in Red Hat Fuse Supported Configurations.
  3. Confirm that your system is running a Java runtime that is supported by Fuse on Apache Karaf. See Supported Java Versions in Red Hat Fuse Supported Configurations.
  4. Ensure that your Java runtime is not installed under a directory path that includes whitespace. For example, C:\Program Files\Java\jdk8 is not an acceptable path. Whitespace in paths causes unpredictable errors in Fuse on Apache Karaf at run time.
  5. Check the list of Red Hat Fuse Supported Standards to confirm that you are using supported standard software.

1.2. Install Fuse on Apache Karaf

The standard installation package for Fuse 7.3 on Karaf is available for download from the Red Hat Customer Portal. It installs the standard assembly of the Apache Karaf container, and provides the full Fuse technology stack.

It is possible to create your own custom assembly of Fuse 7.3, which contains a customized subset of the Fuse features and bundles. The custom quickstart demonstrates how to use Maven to create a custom assembly of Red Hat Fuse. You can install all of the quickstarts from a downloadable file available on the Fuse Software Downloads page.


The system on which you plan to install Fuse meets the hardware and software requirements described in Section 1.1, “Prepare to install Fuse on Apache Karaf”.


  1. In a browser, go to the Fuse Software Downloads page.

    If you are not already logged in to the Red Hat customer portal, there is a prompt to log in and then the download page appears.

    If you do not have customer portal log-in credentials, in the box that asks if you are new to Red Hat, click Register to obtain them, and then log in.

  2. In the Fuse Software Downloads page, to the right of Red Hat Fuse 7.3 on Karaf Installer, click Download to obtain a local zip file.
  3. Extract the contents of the zip file into a directory for which you have all permissions.

    Do not unpack the zip file into a directory that has spaces or any of the following special characters in its path name: #, %, ^, ". For example, do not unpack into C:\Documents and Settings\Greco#Roman\Desktop\fuse.

  4. If you are using the IBM JDK, in your Fuse installation directory, in the /lib/endorsed directory, remove the saaj-api .jar file, for example:

    rm lib/endorsed/org.apache.servicemix.specs.saaj-api-1.3-2.9.0.jar
  5. Set the JAVA_OPTS environment variable as follows:


    You must set the JAVA_OPTS environment variable before you start Fuse.

  6. Add an administrator user to enable remote access to the Fuse on Karaf container and to access the Fuse Console.

    By default, no users are defined for the container. You can run the container in the foreground in this case, but you cannot access the container remotely and you cannot run it in the background. It is recommended that you create at least one user with the admin role by following these steps:

    1. In a text editor, open the etc/ file, which is in your Fuse installation directory.
    2. Locate the following lines:

      #admin = admin,_g_:admingroup
      #_g_\:admingroup = group,admin,manager,viewer,systembundles,ssh
    3. For each line, remove the leading # character to uncomment the line.
    4. In the first line, change the first instance of admin to a username that you choose, for example user1.
    5. In the same line, change the second instance of admin to a password for that user, for example passw0rd.

      For example:

      user1 = passw0rd,_g_:admingroup
      _g_\:admingroup = group,admin,manager,viewer,systembundles,ssh
    6. Save and close the file.
  7. To start Fuse, run bin/fuse on Linux/Unix or bin\fuse.bat on Windows.
  8. Optionally, to access the Fuse Console, open the provided URL in a web browser and login with the username and password that you set in the etc/ file. For more information about using the Fuse Console see Managing Fuse.

1.3. About running Fuse on Karaf offline

You can run the Apache Karaf container in offline mode, that is, without an Internet connection. However, if you are planning to deploy custom applications to the container, it might be necessary to download additional dependencies to a local Maven repository before you can run the container in offline mode with these applications.

To run the Apache Karaf container in offline mode, it is necessary to distinguish between the following kinds of dependencies:

  • Runtime dependencies are dependencies that are required to run the Apache Karaf container in its default configuration.
  • Build-time dependencies are dependencies that are required to build a custom application, which might include third-party libraries.

Here is a summary of what can be done in offline mode and what needs to be done in online mode (with an Internet connection):

  • Running the Apache Karaf container in its default configuration is supported in offline mode. The default configuration of the Apache Karaf container is specified by the featuresBoot property in the etc/org.apache.karaf.features.cfg file. The required dependencies are provided in the system/ sub-directory of the installation.
  • Installing additional features is, in general, not supported in offline mode. In principle, you can use the features:install command to install any of the features from the standard feature repositories (as specified by the featuresRepositories property in the etc/org.apache.karaf.features.cfg file), but the majority of these features must be downloaded from the Internet and are thus not supported in offline mode.
  • Deploying custom applications is, in general, not supported in offline mode. There may be some cases where an application with a minimal set of build-time dependencies is deployable offline. However, custom applications typically have third-party dependencies that require an Internet connection so that JAR files can be downloaded by Apache Maven.

1.4. Optionally use upstream Apache components

Red Hat Fuse provides an additional package to download, which contains the standard distributions of Apache Camel and Apache CXF. If you want to use a standard, upstream distribution of Apache Camel or Apache CXF (without the OSGi container) use the archived versions in the downloaded extras package.


  1. Log in to the Red Hat customer portal.
  2. Go to the Red Hat Customer Portal→Downloads→Red Hat Fuse→Downloads page.
  3. Select 7.3.0 from the Version drop-down list on the Software Downloads page.
  4. Download the Fuse extras archive.

    The extras archive file contains the following archive files nested inside it:

  5. Copy these files to the desired location and decompress them using the appropriate utility for your platform.

Do not unpack an archive file into a folder that has spaces in its path name. For example, do not unpack into C:\Documents and Settings\Greco Roman\Desktop\fuse.

Chapter 2. Applying Hotfix Patch to Fuse on Apache Karaf

2.1. Patching Features and Bundles

Patches are ZIP archives that contain the updated versions of files present in Fuse on Apache Karaf installation. These include:

  • Bundles: These are the most common and in the simplest case, hotfix patch may include single bundle.
  • Configuration files and scripts that are present respectively in $FUSE_HOME/etc and $FUSE_HOME/bin directories.
  • Libraries that are not ordinary bundles and reside in $FUSE_HOME/lib directory.
  • Feature definition changes: Normally Karaf features are included in descriptors available in the $FUSE_HOME/system directory, but hotfix patches do not change these files. Instead, hot fix patch may alter feature override file which is $FUSE_HOME/etc/org.apache.karaf.features.xml. This allows you to alter feature definitions in hotfix manner by upgrading given feature’s bundles or even make given feature use additional bundle.

Difference between Upgrading and Hotfix Patches

  • Hotfix Patch: A hotfix patch contains fixes for only one or more critical bugs. These are intended to be applied on top of your current Red Hat Fuse distribution. Its main purpose is to update some of the bundles and librabies in an existing distribution.
  • Upgrading: The Fuse on Apache Karaf upgrade mechanism enables you apply fixes to an Apache Karaf container without needing to reinstall an updated version of Fuse on Karaf. It also allows you to roll back the upgrade, if the upgrade causes problems with your deployed applications. The Fuse on Apache Karaf upgrade process updates any files, including bundle JARs, configuration files, and any static files.

For Fuse on Apache Karaf Standalone you can apply the patch using commands from the Karaf console’s patch shell. This approach is non-destructive and reversible. Following procedure can also be used for upgrading Red Hat Fuse on Apache Karaf. For more information of upgrading see Upgrading Fuse on Apache Karaf.

2.2. Applying a Hotfix Patch to Red Hat Fuse on Apache Karaf

You can use the hotfix mechanism to update the available feature definitions and bundles at the same time. The procedure to apply a hotfix patch to the Fuse on Apache Karaf installation is as follows.


  1. Download the required patch from the Customer Portal.
  2. Make a full backup of your Fuse on Apache Karaf installation before upgrading.
  3. Open the terminal and start Fuse on Apache karaf server.

    [user@FUSE_HOME/bin ~] $ ./fuse
  4. Add the patch to the container’s environment by entering the patch:add command. For example, to add the patch file, enter:

    karaf@root()> patch:add 'file:///Downloads/'
    [name]                 [installed] [rollup]   [description]
    my-patch-x 	       false       false       my-patch-x
  5. Simulate installing the patch by entering the patch:simulate command.

    This generates a log of the changes that will be made to the container when the patch is installed, but will not make any actual changes to the container. Review the simulation log to understand these changes.

  6. Enter patch:list command to view a list of added patches. In this list, the entries under the [name] heading are patch IDs.

    [name]                       [installed]   [description]
    my-patch-x                   false
  7. Apply a patch to the container by entering the patch:install command and specifying the patch ID for the patch that you want to apply.

    patch:install my-patch-x

2.3. Rolling back a Patch

You can rollback the installed hotfix patch and restore it to pre-patch behavior using the patch:rollback command, as follows:


  1. Enter the patch:list command to obtain the patch ID of the most recently installed patch.
  2. To rollback the updated bundle enter the following command:

    karaf@root()> patch:rollback my-patch-x
    INFO : org.jboss.fuse.modules.patch.patch-management (2): Rolling back non-rollup patch "my-patch-x"
    removing overriden feature: hawtio-rbac/2.0.0.fuse-000117
    refreshing features
    Enter feature:info command to view the information about the feature.
    karaf@root()> feature:info hawtio-rbac
    Feature hawtio-rbac 2.0.0.fuse-000117
          Installs the hawtio RBAC enabler bundle(s)
    Feature has no configuration
    Feature has no configuration files
    Feature has no dependencies.
    Feature contains followed bundles:
    Feature has no conditionals.

Chapter 3. Set up Maven locally

Typical Fuse application development uses Maven to build and manage projects.

The following topics describe how to set up Maven locally:

3.1. Prepare to set up Maven

Maven is a free, open source, build tool from Apache. Typically, you use Maven to build Fuse applications.


  1. Download the latest version of Maven from the Maven download page.
  2. Ensure that your system is connected to the Internet.

    While building a project, the default behavior is that Maven searches external repositories and downloads the required artifacts. Maven looks for repositories that are accessible over the Internet.

    You can change this behavior so that Maven searches only repositories that are on a local network. That is, Maven can run in an offline mode. In offline mode, Maven looks for artifacts in its local repository. See Section 3.3, “Use local Maven repositories”.

3.2. Add Red Hat repositories to Maven

To access artifacts that are in Red Hat Maven repositories, you need to add those repositories to Maven’s settings.xml file. Maven looks for the settings.xml file in the .m2 directory of the user’s home directory. If there is not a user specified settings.xml file, Maven uses the system-level settings.xml file at M2_HOME/conf/settings.xml.


You know the location of the settings.xml file in which you want to add the Red Hat repositories.


In the settings.xml file, add repository elements for the Red Hat repositories as shown in this example:

<?xml version="1.0"?>

          <name>JBoss Public Repository Group</name>
          <name>JBoss Public Repository Group</name>



3.3. Use local Maven repositories

If you are running the Apache Karaf container without an Internet connection, and you need to deploy an application that has dependencies that are not available offline, you can use the Maven dependency plug-in to download the application’s dependencies into a Maven offline repository. You can then distribute this customized Maven offline repository to machines that do not have an Internet connection.


  1. In the project directory that contains the pom.xml file, download a repository for a Maven project by running a command such as the following:

    mvn org.apache.maven.plugins:maven-dependency-plugin:3.1.0:go-offline -Dmaven.repo.local=/tmp/foo

    In this example, Maven dependencies and plug-ins that are required to build the project are downloaded to the /tmp/foo directory.

  2. Edit the etc/org.ops4j.pax.url.mvn.cfg file to set org.ops4j.pax.url.mvn.offline to true. This enables offline mode:

    # If set to true, no remote repository will be accessed when resolving artifacts
    org.ops4j.pax.url.mvn.offline = true
  3. Distribute this customized Maven offline repository internally to any machines that do not have an Internet connection.

3.4. About Maven artifacts and coordinates

In the Maven build system, the basic building block is an artifact. After a build, the output of an artifact is typically an archive, such as a JAR or WAR file.

A key aspect of Maven is the ability to locate artifacts and manage the dependencies between them. A Maven coordinate is a set of values that identifies the location of a particular artifact. A basic coordinate has three values in the following form:


Sometimes Maven augments a basic coordinate with a packaging value or with both a packaging value and a classifier value. A Maven coordinate can have any one of the following forms:


Here are descriptions of the values:

Defines a scope for the name of the artifact. You would typically use all or part of a package name as a group ID. For example, org.fusesource.example.
Defines the artifact name relative to the group ID.
Specifies the artifact’s version. A version number can have up to four parts: n.n.n.n, where the last part of the version number can contain non-numeric characters. For example, the last part of 1.0-SNAPSHOT is the alphanumeric substring, 0-SNAPSHOT.
Defines the packaged entity that is produced when you build the project. For OSGi projects, the packaging is bundle. The default value is jar.
Enables you to distinguish between artifacts that were built from the same POM, but have different content.

Elements in an artifact’s POM file define the artifact’s group ID, artifact ID, packaging, and version, as shown here:

<project ... >

To define a dependency on the preceding artifact, you would add the following dependency element to a POM file:

<project ... >

It is not necessary to specify the bundle package type in the preceding dependency, because a bundle is just a particular kind of JAR file and jar is the default Maven package type. If you do need to specify the packaging type explicitly in a dependency, however, you can use the type element.

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