Chapter 6. Relational Database Setup

These are the steps you will need to perform to get an RDBMS configured for Red Hat Single Sign-On.

This chapter will use PostgresSQL for all its examples. Other databases follow the same steps for installation.

Find and download the JDBC driver JAR for your RDBMS. Before you can use this driver, you must package it up into a module and install it into the server. Modules define JARs that are loaded into the Red Hat Single Sign-On classpath and the dependencies those JARs have on other modules. They are pretty simple to set up.

Within the …​/modules/ directory of your Red Hat Single Sign-On distribution, you need to create a directory structure to hold your module definition. The convention is use the Java package name of the JDBC driver for the name of the directory structure. For PostgreSQL, create the directory org/postgresql/main. Copy your database driver JAR into this directory and create an empty module.xml file within it too.

After you have done this, open up the module.xml file and create the following XML:

<?xml version="1.0" ?>
<module xmlns="urn:jboss:module:1.3" name="org.postgresql">

    <resources>
        <resource-root path="postgresql-9.4.1212.jar"/>
    </resources>

    <dependencies>
        <module name="javax.api"/>
        <module name="javax.transaction.api"/>
    </dependencies>
</module>

The module name should match the directory structure of your module. So, org/postgresql maps to org.postgresql. The resource-root path attribute should specify the JAR filename of the driver. The rest are just the normal dependencies that any JDBC driver JAR would have.

The next thing you have to do is declare your newly packaged JDBC driver into your deployment profile so that it loads and becomes available when the server boots up. Where you perform this action depends on your operating mode. If you’re deploying in standard mode, edit …​/standalone/configuration/standalone.xml. If you’re deploying in standard clustering mode, edit …​/standalone/configuration/standalone-ha.xml. If you’re deploying in domain mode, edit …​/domain/configuration/domain.xml. In domain mode, you’ll need to make sure you edit the profile you are using: either auth-server-standalone or auth-server-clustered

Within the profile, search for the drivers XML block within the datasources subsystem. You should see a pre-defined driver declared for the H2 JDBC driver. This is where you’ll declare the JDBC driver for your external database.

  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
     <datasources>
       ...
       <drivers>
          <driver name="h2" module="com.h2database.h2">
              <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
          </driver>
       </drivers>
     </datasources>
  </subsystem>

Within the drivers XML block you’ll need to declare an additional JDBC driver. It needs to have a name which you can choose to be anything you want. You specify the module attribute which points to the module package you created earlier for the driver JAR. Finally you have to specify the driver’s Java class. Here’s an example of installing PostgreSQL driver that lives in the module example defined earlier in this chapter.

  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
     <datasources>
       ...
       <drivers>
          <driver name="postgresql" module="org.postgresql">
              <xa-datasource-class>org.postgresql.xa.PGXADataSource</xa-datasource-class>
          </driver>
          <driver name="h2" module="com.h2database.h2">
              <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
          </driver>
       </drivers>
     </datasources>
  </subsystem>

After declaring your JDBC driver, you have to modify the existing datasource configuration that Red Hat Single Sign-On uses to connect it to your new external database. You’ll do this within the same configuration file and XML block that you registered your JDBC driver in. Here’s an example that sets up the connection to your new database:

  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
     <datasources>
       ...
       <datasource jndi-name="java:jboss/datasources/KeycloakDS" pool-name="KeycloakDS" enabled="true" use-java-context="true">
           <connection-url>jdbc:postgresql://localhost/keycloak</connection-url>
           <driver>postgresql</driver>
           <pool>
               <max-pool-size>20</max-pool-size>
           </pool>
           <security>
               <user-name>William</user-name>
               <password>password</password>
           </security>
       </datasource>
        ...
     </datasources>
  </subsystem>

Search for the datasource definition for KeycloakDS. You’ll first need to modify the connection-url. The documentation for your vendor’s JDBC implementation should specify the format for this connection URL value.

Next define the driver you will use. This is the logical name of the JDBC driver you declared in the previous section of this chapter.

It is expensive to open a new connection to a database every time you want to perform a transaction. To compensate, the datasource implementation maintains a pool of open connections. The max-pool-size specifies the maximum number of connections it will pool. You may want to change the value of this depending on the load of your system.

Finally, with PostgreSQL at least, you need to define the database username and password that is needed to connect to the database. You may be worried that this is in clear text in the example. There are methods to obfuscate this, but this is beyond the scope of this guide.

The configuration for this component is found in the standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode.

<subsystem xmlns="urn:jboss:domain:keycloak-server:1.1">
    ...
    <spi name="connectionsJpa">
     <provider name="default" enabled="true">
         <properties>
             <property name="dataSource" value="java:jboss/datasources/KeycloakDS"/>
             <property name="initializeEmpty" value="false"/>
             <property name="migrationStrategy" value="manual"/>
             <property name="migrationExport" value="${jboss.home.dir}/keycloak-database-update.sql"/>
         </properties>
     </provider>
    </spi>
    ...
</subsystem>

Possible configuration options are:

Database schema in Red Hat Single Sign-On only accounts for Unicode strings in the following special fields:

Otherwise, characters are limited to those contained in database encoding which is often 8-bit. However, for some database systems, it is possible to enable UTF-8 encoding of Unicode characters and use full Unicode character set in all text fields. Often, this is counterbalanced by shorter maximum length of the strings than in case of 8-bit encodings.

Some of the databases require special settings to database and/or JDBC driver to be able to handle Unicode characters. Please find the settings for your database below. Note that if a database is listed here, it can still work properly provided it handles UTF-8 encoding properly both on the level of database and JDBC driver.

Technically, the key criterion for Unicode support for all fields is whether the database allows setting of Unicode character set for VARCHAR and CHAR fields. If yes, there is a high chance that Unicode will be plausible, usually at the expense of field length. If it only supports Unicode in NVARCHAR and NCHAR fields, Unicode support for all text fields is unlikely as Keycloak schema uses VARCHAR and CHAR fields extensively.