# Feature Level Visibility and Security¶

GeoMesa supports security on a per-feature level, which allows data to be filtered on a granular level for different users. It is a more advanced tutorial; you should already be familiar with the basics of GeoMesa and GeoServer. This tutorial targets Accumulo - GeoMesa also supports HBase visibilities through the same mechanisms, but the HBase configuration required is not covered here. See HBase Visibilities for more information on HBase.

In this tutorial, you will learn how to:

1. Set visibilities on your features during ingestion into GeoMesa
2. Apply authorizations to your queries through GeoMesa

For information how to configure a secure environment that can leverage feature visibilities, see GeoMesa Authorizations.

## Prerequisites¶

Before you begin, you must have the following:

• Java JDK 1.8
• Apache Maven 3.5.2 or later
• a GitHub client
• an Accumulo 1.9.1 or later instance
• an Accumulo user that has both create-table and write permissions
• the GeoMesa distributed runtime installed for your instance

If you are not familiar with Accumulo authorizations, you should review the relevant Accumulo documentation, with more examples here.

This tutorial operates by inserting and then querying several thousand features. The features are inserted with visibility labels, and then queried with two different users to show how authorizations work.

Pick a reasonable directory on your machine, and run:

$git clone https://github.com/geomesa/geomesa-tutorials.git$ cd geomesa-tutorials


Warning

Make sure that you download or checkout the version of the tutorials project that corresponds to your GeoMesa version. See About Tutorial Versions for more details.

To ensure that the quick start works with your environment, modify the pom.xml to set the appropriate versions for Accumulo, Hadoop, etc.

For ease of use, the project builds a bundled artifact that contains all the required dependencies in a single JAR. To build, run:

$mvn clean install -pl geomesa-tutorials-accumulo/geomesa-tutorials-accumulo-feature-level-vis -am  ## Run the Tutorial¶ On the command line, run: $ java -cp geomesa-tutorials-accumulo/geomesa-tutorials-accumulo-feature-level-vis/target/geomesa-tutorials-accumulo-feature-level-vis-${geomesa.version}.jar \ org.geomesa.example.accumulo.vis.FeatureLevelVisibilityTutorial \ --accumulo.instance.id <instance> \ --accumulo.zookeepers <zookeepers> \ --accumulo.user <user> \ --accumulo.password <password> \ --accumulo.catalog <table>  where you provide the following arguments: • <instance> the name of your Accumulo instance • <zookeepers> your Zookeeper nodes, separated by commas • <user> the name of an Accumulo user that has permissions to create, read and write tables • <password> the password for the previously-mentioned Accumulo user • <table> the name of the destination table that will accept these test records. This table should either not exist or should be empty Warning If you have set up the GeoMesa Accumulo distributed runtime to be isolated within a namespace (see Namespace Install) the value of <table> should include the namespace (e.g. myNamespace.geomesa). Optionally, you can also specify that the tutorial should delete its data upon completion. Use the --cleanup flag when you run to enable this behavior. Once run, you should see the following output: Loading datastore Creating schema: GLOBALEVENTID:String,Actor1Name:String,Actor1CountryCode:String,Actor2Name:String,Actor2CountryCode:String,EventCode:String,NumMentions:Integer,NumSources:Integer,NumArticles:Integer,ActionGeo_Type:Integer,ActionGeo_FullName:String,ActionGeo_CountryCode:String,dtg:Date,geom:Point,visibility:String Generating test data Writing test data Wrote 2356 features Done  ## Looking at the Code¶ The source code is meant to be accessible for this tutorial. The main logic is contained in org.geomesa.example.accumulo.vis.FeatureLevelVisibilityTutoriall in the geomesa-tutorials-accumulo/geomesa-tutorials-accumulo-feature-level-vis module. Some relevant methods are: • getSimpleFeatureType add an extra attribute to the base GDELT feature type • getTestFeatures set visibilities on each feature SimpleFeature feature = features.get(i); String visibilities; if (i % 2 == 0) { visibilities = "admin"; } else { visibilities = "user|admin"; } // set the visibility as user data in the feature SecurityUtils.setFeatureVisibility(feature, visibilities); // also set as an attribute for visualization feature.setAttribute("visibility", visibilities);  This code snippet shows how you can specify the visibilities for each feature. SecurityUtils.setFeatureVisibility sets the visibilities string as user data in the feature. When writing to Accumulo, GeoMesa will use that user data to apply the appropriate Accumulo visibility string to the record. Half the data is marked as admin, which means only a user with that authorization can view it. The other half is marked as user|admin, which means that both admin authorizations and user authorizations are sufficient to view the data. Unless users are explicitly granted permissions to read features with that level of authorization, we cannot visualize the data in a meaningful way. Next we will add new Accumulo users to do just that. ## Adding New Accumulo Users¶ In this part of the tutorial, we’ll use the Accumulo shell to add users. First, login to Accumulo with: $ accumulo shell -u <username> -p <password>


You should then see something similar to this:

Shell - Apache Accumulo Interactive Shell
-
- version: 1.8.1
- instance name: xxxxx
- instance id: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
-
- type 'help' for a list of available commands
-
myUser@accumulo>


Now, we’re ready to add new users to Accumulo with the Accumulo shell createuser command. At the prompt, run:

> createuser user
Enter new password for 'user': ***********


With these new users added, we’re going to give them the proper authorizations with the setauths command:

> setauths -s admin,user -u admin
> setauths -s user -u user


This will grant authorizations admin,user to admin, meaning as the user admin, one will be able to read both features written with the visibility user and features written with the visibility admin. Additionally, the user user will be granted user authorizations, meaning they can only view features of visibility user. They will never see features written with the visibility admin.

Next we’ll grant permissions to the read the appropriate tables to user and admin. Replace <table> in the following command with the table you specified when running the tutorial code.

> grant -u user -p <table>.* Table.READ


To verify user permissions you can switch users in the accumulo console by using:

> user admin


We can now move to the table we’d like to verify. Here we use <table>_z2_v2 but any valid table will work.

> table <table>_z2_v2
> scan
---------------hit any key to continue or 'q' to quit ------------------


scan should return a sample of the data if everything is configured correctly.

Next we’ll use GeoServer to visualize feature level visibility.

## GeoServer Visualization¶

Assuming you have already set up GeoServer as described in the GeoMesa User Manual, we’re going to add a new DataStore to GeoServer. First, login to GeoServer, and then click “Add stores” from the homepage.

Next, click the link to add a new “Accumulo (GeoMesa)” store and name it feature-level-visibility-admin. Fill in the correct connection parameters to make contact with GeoMesa/Accumulo, but be sure to use admin for the “user” parameter.

Then, publish your layer when prompted by GeoServer. Remember to click the “Compute from data” and “Compute from native bounds” links on the “Add Layer” page, and click “Save”.

Repeat the above steps one more time to add an additional DataStore with the same parameters, but this time, name it feature-level-visibility-user and use user for the “user” parameter.

With your layers added in GeoServer, we’re nearly ready to visualize the data. One final step is adding our custom SLD that will style your features to make visualizations of the data even easier to understand.

Download feature-level-vis.sld, or copy the contents, and add it as a Style in GeoServer. It will style the points on a map based on the visibility attribute present.

Lastly, click on “Layer Preview” in the left hand sidebar and find your two newly added layers. If everything went correctly, you should see fewer results returning in the user layer than in the admin layer, and this is expected behavior. Because user has only been granted permission to view features with the user visibility, only that half of the records are returned. However, the admin user is granted permission to see both admin and user visibilities.

## Expanding The Concept¶

In this very simple example, you wrote features of two different visibilities, added two new users to Accumulo, and granted them separate authorization levels to be able to view portions of the data. This tutorial has real-world use cases in security and data integrity. For example, when storing sensitive data and having users of varying authorization and security levels querying that data, visibility labels ensure that sensitive data is not leaked to a user of a lower level of security.

The concept of feature level visibility can be extended and modified to have many more, or only a few, visibility levels. And with GeoServer being flexible and extensible, writing a module to consider feature level security in GeoServer is relatively painless.

GeoMesa also provides a mechanism to have authorizations applied on a per-user level, instead of a per-datastore level. More information, including integration with PKI and LDAP, can be found in the Authorizations tutorial under Applying Authorizations and Visibilities to GeoServer Using PKIS and LDAP.