The VTE from the Visa Project. For more information about VISA visit please.
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.

VISA VISA Topologie Editor DECOIT GmbH

VISA Topology-Editor

The VISA Topology-Editor (VTE) is a topology editor prototype, which was developed by the DECOIT GmbH, located in Bremen (Germany), during the VISA research project. For more information about VISA please visit Please remember this is a prototype release and it is neither optimized for performance nor stability! Do not use it in a production environment!

To provide full functionality, it requires an installation of the Interconnected-asset Ontology Tool (IO-Tool), developed by the Fraunhofer SIT, which uses OpenStack to replicate the designed topology into a virtual environment. Without that tool it is possible to design topologies from scratch or import and edit topologies from RDF/XML files using the same RDF data model that is used for communication between VTE and IO-Tool. But it is NOT possible to create a virtual infrastruture from this information since this requires the topology to be stored in an IO-Tool instance.

The VTE is copyrighted (C) 2013 by DECOIT GmbH and published under the terms of the GPLv3.



The backend needs a Java SSL KeyStore and a Java SSL TrustStore (Tutorial) to communicate with the IO-Tool. They should be located in the backend/res/ssl directory. If you store them in another place, it may be required to change the backend/build.xml file. The IO-Tool server's SSL certificate must be added to those stores. If you do not intend to use the IO-Tool functionality, creation of the Key- and TrustStore is not required.

After creating the SSL stores edit the backend/ file. Fill in the locations and passwords to the Key- and TrustStore (see Usage section for further information), then save the file as backend/ and make sure it is executable. This last step is required even if you do not use the IO-Tool functionality. In this case you may just rename the sample file. DO NOT REMOVE THE COMMAND LINE PARAMETERS FROM THIS FILE! They are required to start the backend. If not needed, just leave them blank.

Besides the SSL stores an installation of graphviz version 2.28 or higher is required. Versions below 2.28 will not work properly because of problems with the neato layouter. Ubuntu ships with graphviz 2.26 but there are development packages available from the graphviz homepage or by adding this PPA to apt.


To install the backend you need a Java SE 7 JDK and Apache Ant. Java versions prior to Java SE 7 are not supported. If those requirements are met, just run ant in the backend directory. It will create a directory called dist and places the installation inside. You may copy the contents of this directory to any location you want. The user which will run the backend needs some filesystem permissions set in the directory of the backend:

  • The installation directory must be writeable to create the log files
  • The export/ directory must be writeable
  • All other backend files and directories must be readable

After compiling and packaging using ant change directory to the location you copied the dist contents to and run ./ This will install the symbolic link /usr/bin/visabackend to allow starting the backend by just typing visabackend on the console. This step is optional if you want to run the startup script directly.

To create JavaDoc from the source files run ant javadoc. The documentation will be generated in the doc/ directory.


The backend can be started by running visabackend on the command line, if you installed the symbolic link in the last installation step. If you did not, you have to change directory to the location the backend files are installed and manually run the script ./ Both ways will start the backend, by default listening on port 8080.

There are some command line switches available to the show information or change parameters of the backend. You can view them on the console by calling visabackend -h. The following switches are available:

  • -h, --help
    • Print usage information and quit
  • -v, --version
    • Print version information and quit
  • -p [port], --port [port]
    • Change the listening port for the backend to [port]

Additionally, there are the SSL parameters available, which are already set in in the script. You may use these switches to override the values set in the script (the direct parameters are parsed after the parameters in the script), but it is recommended to change them in the startup script instead. The available commands are:

  • --sslkey [path]
    • Path to the SSL KeyStore file
  • --sslkeyp [pwd]
    • Password/secret required to access the SSL KeyStore
  • --ssltrust [path]
    • Path to the SSL TrustStore file
  • --ssltrustp [pwd]
    • Password/secret required to access the SSL TrustStore



The frontend requires an Apache HTTP Server. It was developed on version 2.2 but may run on earlier versions (2.0 or 2.1) too. The following modules must be installed and enabled:

  • mod_php5, version 5.3 or later
  • mod_proxy
  • mod_proxy_http
  • mod_rewrite

The following settings should be made in the php.ini file to allow the file upload function to work properly:

  • post_max_size = 10M
  • upload_max_filesize = 10M


Copy the contents of the frontend/ directory of the distribution to the document root or a subdirectory of any configured vHost. The following filesystem permissions must be set (all apply to the user running the HTTP server):

  • All files and directories of the frontend must be readable
  • The import/ directory must be writeable

After copying the files to the desired location the configuration file for the vHost hosting the frontend files must be edited. Inside the VirtualHost block the following directives must be added:

  • RewriteEngine On
  • RewriteOptions Inherit

Inside the Directory block, which describes the directory the frontend files are located in, the following directives must be inserted. If you put the files in a subdirectory and no Directory block for that exists in the configuration file, create one.

  • RewriteEngine On
  • RewriteBase /
  • RewriteRule ^ajax(.*$) http://localhost:8080/ajax$1 [P]

This will redirect all AJAX calls from the frontend to the backend listening on port 8080. If you run the backend on another port, adjust the port in the RewriteRule directive to match your chosen port.


After you completed all installation steps just fire up your browser and open the URL of the frontend on your webserver to start using the VTE. The backend must be running to use the editor at all. If the connection to the backend fails the GUI will block and ask you to start the backend. After you have done that just refresh the page. If it still fails most likely there is something wrong with the configuration you made for the Apache HTTP server.