WB-Analyse-4

This project contains a simple HTTP-Server developed with Java. The HTTP-Server works as a REST-API to analyze social network graphs.

Dependencies

The project is developed with Java 15 and heavily uses features introduced in Java 15 such as text blocks. As our build automation tool we use Maven thus the following dependencies are required. In addition to store the data about interactions a MariaSQL database is used. Other SQL-based databases are not supported. For generating graphs as images GraphViz is required as well.

• Maven3.2 or later - Build the project
• JDK 15 or later - Run the project
• A running MariaDB - Store the interaction data
• Graphviz - Generate graph images for webapp

Graphviz

For the visual representation of graphs we use Graphviz to generate SVGs. Therefore, Graphviz should be installed if you want to use the webapp. If you use Windows it is easiest to install Graphviz in the WSL. When generating Graphs following installation locations are searched in the given order

• PATH
• WSL

MariaDB

To connect to the Database a valid URL to the database is required. How to set the url to the database for the server is explained later. For further details see the official documentation.

Build

To build the project into an executable JAR run

$ mvn compile assembly:single

You can find the JAR in the generated folder target as analyse4-server-1.0-jar-with-dependencies.jar".

Running and deploying the JAR

To run the executable JAR run

$ java -jar target/analyse4-server-1.0-jar-with-dependencies.jar

Deployment

The deployment of the server is done by copying the jar to the destination server and running it.

Manual deployment with ssh

The easy way to deploy the JAR just once is to use scp to copy the executable JAR to a SSH-Server. This can be done by running

 $ scp target/analyse4-server-1.0-jar-with-dependencies.jar USER@URL:path/to/your/project 

For additional information see the man-page for scp documentation After that you will just need to start the jar on the ssh server.

Automating the deployment process with Maven

To setup an automated deployment process there are a few extra step but will make it easier to deploy the project multiple times.
First thing you will have to do is to create a file called settings.xml It should look like this.

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 https://maven.apache.org/xsd/settings-1.0.0.xsd">
    <servers>
        <server>
            <id>production</id>
            <username>SSH-Username</username>
            <password>SSH-Password</password>
        </server>
    </servers>
</settings>

Obviously you should replace SSH-Username and SSH-Password with your SSH-Username and SSH-Password. You are also required to modify the pom-xml file as follows

               ...

    <distributionManagement>
        <repository>
            <id>production</id>
            <url>SSH-Server-URL</url>
        </repository>
    </distributionManagement>

Again replace SSH-Server-URL with your own URL. After all that is done simply run

$ mvn deploy -s settings.xml

Configuration of the deployed server

To configure the deployed server create a file called config.xml in the folder with the JAR. With the following content.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
    <entry key="port">8080</entry>                                  <!-- port for the http server  -->
    <entry key="logger_level">BASIC</entry>                         <!-- details logged by logger  -->
    <entry key="admin_user">admin</entry>                           <!-- username for the webapp   -->
    <entry key="admin_pass"></entry>                                <!-- password for the webapp   -->
    <entry key="db_url">jdbc:mariadb://URL-to-DB</entry>            <!-- url for the database      --> 
    <entry key="db_user"></entry>                                   <!-- username for the database -->
    <entry key="db_pass"></entry>                                   <!-- password for the database -->
</properties>

You might as well just specify a subset of the given properties. Properties not specified will be added with default values after you launch the server. If you do not create a config file it is created for you on the first launch of the JAR.

Updating the configuration

If you want to update the configuration you need to restart the server after you edited the config.xml.

Webpage for administration

The server has a webpage to display some of its functionality. When running locally the server can be reached via localhost at the port set in the config.xml and the endpoint /admin e.g. http://localhost:8080/admin.

It is lightly protected with a username and password that can also be set in the config.xml. It is noteworthy that this is not a secure protection and merely the bare minimum to protect the webpage from being accessed by non-administrators. Since the server is not using https the password can be sniffed by an attacker.

Note that by default no password is set and the default username is admin. Hence, the default is not secure.

Api documentation

This lightweight HTTP-Server provides several routes each with an individual documentation which can be found here

• Hello world /
• Webpage /admin
• Add interactions betweens users /interaction
• Generate graph from interactions /graph
• Receive analysed data from interactions /network-analysis
• Receive the graph from interacitons as a svg /graph-svg
• Shutdown the server /shutdown
• Receive all stored ids (persons) /ids