A generic Mongo authentication realm for Tomcat

To use the MongoRelam you need to do the following 3 steps:

The realm jar needs to be copied into the tomcat /lib folder.

Add the following entry to the context.xml

 <Realm 
     authDB="db-containing"
     authCollection="users" 
     authUserField="username" 
     authPasswordField="password" 
     authRoleField="" 
     className="de.locked.tomcat.mongorealm.GenericMongoRealm" 
     defaultDbHost="localhost" 
     defaultDbPass="" 
     defaultDbUser="" 
     defaultRole="user"
     digest = "SHA-256"/>

activate the password protection (in this case for all files under /api/auth/)

 <security-constraint>
     <web-resource-collection>
         <web-resource-name>auth</web-resource-name>
         <url-pattern>/api/auth/*</url-pattern>
     </web-resource-collection>
     
     <auth-constraint>
         <role-name>user</role-name>
     </auth-constraint>
 </security-constraint>
 
 <login-config>
     <auth-method>BASIC</auth-method>
     <realm-name>Basic Authentication</realm-name>
 </login-config>
 
 <security-role>
     <role-name>user</role-name>
 </security-role>

If you don't want to enter the database credentials in the XML, you can also set environment variables:
```
 OPENSHIFT_MONGODB_DB_HOST
 OPENSHIFT_MONGODB_DB_USERNAME
 OPENSHIFT_MONGODB_DB_PASSWORD
```

anschuermann/Jee-MongoRealm

A generic Mongo authentication realm for Tomcat