Tag Archives: ssh server

Installing apache karaf on debian

Until the RFP (Request For Packaging) bug for karaf in the debian bug tracker is resolved, here is an APT archive with a karaf package for debian (architecture “all”).  The package is created using native debian packaging tools, and built from a source tarball and the APT archive itself is created, using aptly.

The package has been tested on Debian 9 “stretch” (the current stable), amd64.

Do the following commands as root on a debian GNU/linux system:

  1. Add the key for the APT archive
    wget -O - https://apt.bang.priv.no/apt_pub.gpg | apt-key add -
  2. Open the /etc/apt/sources.list file in a text editor, and add the following lines:
    # APT archive for apache karaf
    deb http://apt.bang.priv.no/public stable main
  3. Install karaf with apt-get
    apt-get update
    apt-get install openjdk-8-jdk karaf
  4. Log in with SSH (password is “karaf” (without the quotes)) and try giving some commands:
    ssh -p 8101 karaf@localhost


Packaging karaf with native debian packaging tools

Note! This is an improvement over the packaging in  Installing apache karaf on debian stretch, this package is packaged using native debian packaging tools instead of fpm, and is built from the karaf source tarball instead of the karaf binary tarball.

Apache karaf is an OSGi container and application server that is provisioned from maven, and has an ssh server. Basically it is possible to start an empty karaf, ssh in and give some commands to install an application using maven.

There still isn’t a native .deb package on maven (see  the RFP (Request For Packaging) bug for karaf in the debian bug tracker), but this package can be installed from my own maven repository.

The packacing projecct can be found on github: https://github.com/steinarb/karaf-debian

Procedure to build the package

  1. Install the required build tools
    apt-get update
    apt-get install openjdk-sdk git maven-debian-helper devscripts
  2. Clone the karaf package repository
    mkdir -p ~/git
    cd ~/git/
    git clone https://github.com/steinarb/karaf-debian.git
  3. Build the package
    cd ~/git/karaf-debian/

After this, there will be a karaf-*.deb package in the directory above the karaf-debian directory.

Installing apache karaf on debian stretch

Edit: It is now possible to install karaf on debian without building it yourself, the package installed is not the one described here, but the new and improved package built from source with native debian packaging tools, that can be found here  https://github.com/steinarb/karaf-debian

Apache karaf is an OSGi container/application server with some nice properties:

  1. It has an SSH server you can log into and a command line where you can inspect and configure the karaf instance
  2. It can be provisioned using apache maven, basically you can start with an empty karaf, ssh into the SSH server and pull in and start your application using “maven magic”
  3. It is much simpler to get an OSGi application up and running in apache karaf, than in any other system I have tried, since I first was to introduced to OSGi in 2006
  4. Karaf can also be used to run non-OSGi applications packaged as jar or war files
  5. In a development setting is very simple to deploy new versions of the code using maven and remote debug the deployed code frome eclipse or IntelliJ

Running karaf on a debian GNU/linux system is a little hampered by there not being a native .deb package. I have opened an RFP (Request For Packaging) bug for karaf in the debian bug tracker. When/if that issue is ever resolved as done, karaf will be easily availabel on debian and also on all of the distros that are based on debian (e.g. ubuntu and mint).

Until then do my own debian packaging. I forked the packaging I found at https://github.com/DemisR/karaf-deb-packaging and made some changes:

  1. Switched from oracle JDK 8, to openjdk 8
  2. Updated to karaf version 4.0.7 (the currently newest stable release at the time of forking), later upgraded to karaf 4.1.1 and again upgraded to karaf 4.1.2
  3. Use /var/lib/karaf/data instead of /usr/local/karaf/data
  4. Use package version “-1” instead of “-3”
  5. Switched from using the the service wrapper (karaf-wrapper) to plain systemd start using the scripts and config from bin/contrib in the karaf distribution
  6. Made the stop of running services more robust

The resulting .deb package will follow the usual service pattern of a debian service: the service will run with a user named after the service (i.e. user “karaf” which is the single member of group “karaf” and the owner of all files the service need to touch). The service will log to the regular debian syslog. The configuration will end up in /etc/karaf and all files not part of the installation will be left untouched on a .deb package uninstall and upgrade.

My fork of the packaging, lives at https://github.com/steinarb/karaf-deb-packaging

To create the package and install karaf, do the following steps:

  1. Log in as root on a debian system
  2. Install the prequisites for building the package, debian packages and ruby gem:
    apt-get update
    apt-get install git maven openjdk-8-jdk postgresql ruby ruby-dev build-essential
    gem install fpm
  3. Clone the packaging project and build the deb package:
    cd /tmp
    git clone https://github.com/steinarb/karaf-deb-packaging
    cd karaf-deb-packaging
    mkdir -p /root/debs
    cp *.deb /root/debs
  4. Install the .deb package:
    dpkg --install karaf_4.1.4-1_all.deb

After karaf has been installed it is possible to log in as user “karaf”, with the following command

ssh -p 8101 karaf@localhost

The password is also “karaf” (without the quotes).

This opens the karaf console command line

        __ __                  ____
       / //_/____ __________ _/ __/
      / ,<  / __ `/ ___/ __ `/ /_
     / /| |/ /_/ / /  / /_/ / __/
    /_/ |_|\__,_/_/   \__,_/_/

  Apache Karaf (4.1.4)

Hit '<tab>' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit 'system:shutdown' to shutdown Karaf.
Hit '<ctrl-d>' or type 'logout' to disconnect shell from current session.


At this command line, you can eg.

  1. install an application
  2. start, stop and list running applications
  3. set the configuration used by the applications

But all of these except for the first, will be items for later posts.