Assembly is done using the provided Assembler:

public void assemble( ModuleAssembly module )
    throws AssemblyException
{
  [...snip...]

    new EhCacheAssembler().
        withConfig( confModule, Visibility.layer ).
        assemble( module );
}

Here are the configuration properties for the EhCache EntityStore Cache:

public interface EhCacheConfiguration
    extends ConfigurationComposite
{

    @Optional @UseDefaults
    Property<Boolean> clearOnFlush();

    @Optional @UseDefaults
    Property<Integer> diskAccessStripes();

    @Optional @UseDefaults
    Property<Long> diskExpiryThreadIntervalSeconds();

    /**
     * Cache Persistence Strategy.
     *
     * Can be:
     * <ul>
     *   <li>LOCALTEMPSWAP: Standard open source (non fault-tolerant) on-disk persistence.</li>
     *   <li>LOCALRESTARTABLE: Enterprise fault tolerant persistence.</li>
     *   <li>NONE: No persistence.</li>
     *   <li>DISTRIBUTED: Terracotta clustered persistence (requires a Terracotta clustered cache).</li>
     * </ul>
     * Defaults to NONE.
     */
    @Optional
    Property<Strategy> persistenceStrategy();

    @Optional @UseDefaults
    Property<String> diskStorePath();

    @Optional @UseDefaults
    Property<Integer> diskSpoolBufferSizeMB();

    @Optional @UseDefaults
    Property<Boolean> eternal();

    @Optional @UseDefaults
    Property<Boolean> loggingEnabled();

    /**
     * Number of objects the ehCache should keep in memory.
     * Defaults to 1000
     *
     * @return The maximum number of elements to be kept in memory.
     */
    @Optional @UseDefaults
    Property<Integer> maxElementsInMemory();

    @Optional @UseDefaults
    Property<Integer> maxElementsOnDisk();

    @Optional @UseDefaults
    Property<String> memoryStoreEvictionPolicy();

    @Optional @UseDefaults
    Property<String> name();

    @Optional @UseDefaults
    Property<String> transactionalMode();

    @Optional @UseDefaults
    Property<Long> timeToLiveSeconds();

    @Optional @UseDefaults
    Property<Long> timeToIdleSeconds();

    @Optional @UseDefaults
    Property<String> cacheManagerName();

    @Optional @UseDefaults
    Property<String> monitoring();

    @Optional @UseDefaults
    Property<Boolean> updateCheck();
}