Overview#

Modern systems can work with different DB. Jans is also not exception from this rule. Currently it can work with different DB types and also can work in hybrid environment where application can use the strong power of each DB. This part is based on jans-orm layer. It has pluggable architecture which allows to add support for more DB in future.

One of the main target of ORM module is to provide simple lightweight layer to access DB. Also it provides abstractions which hide dependency to specific DB.

Supported DB#

Jans has next persistence modules out-of-the-box:

LDAP
Couchbase
Spanner
MySQL
PostgreSQL
Hybrid. This is virtual DB layer which allows to combine few DB types based on record type.

Configuration#

On a Janssen Server instance the type of persistence(DB) used is specified in /etc/jans/conf/jans.properties using the entry as show below:

persistence.type=ldap

Values for property persistence.type is set during the installation and based on choice of persistence(DB) type, it can be one of these supported values:

ldap
couchbase
sql
spanner
hybrid.

Code Connect

In Janssen Server code base, the list of supported persistence types can be found here.

Based on persistent type in use, the corresponding properties file with relevant configuration properties will be available on Janssen Server instance under the directory /etc/jans/conf/. List of configuration files for these persistence types are:

jans-ldap.properties
jans-couchbase.properties
jans-spanner.properties
jans-sql.properties
jans-hybrid.properties

The application reloads configuration from these files after start up or on files date time modification after initialization.

Overriding DB Configuration Properties#

Configuration properties and the values specified under .properties files discussed in above section, can be overridden by dynamically passing them as a JVM parameter or as an environment variable.

Cloud-native Installations#

For Janssen Server installations using Helm, Docker, or local Kubernetes, dynamically passing DB configuration properties can be done by specifying environment variables.

For example:

Override connection URI for one specific component. For instance, jans-auth component
```
CN_AUTH_JAVA_OPTIONS=-Dconnection.uri=new-mysql-uri
```
Override connection URI globally for all Janssen Server modules
```
CN_JAVA_OPTIONS=-Dconnection.uri=new-mysql-uri
```
or by exporting system-level environment variable as below
```
CONNECTION_URI=new-mysql-uri
```
For a Helm installation you can globally override hte URI in the values.yaml

global:
  usrEnvs:
    normal:
      CN_JAVA_OPTIONS: -Dconnection.uri=jdbc:postgresql://postgresql.sql.svc.cluster.local:5432/jansdb

Or for a specific component like the auth server:

auth-server:
  usrEnvs:
    normal:
      CN_JAVA_OPTIONS: -Dconnection.uri=jdbc:postgresql://postgresql.sql.svc.cluster.local:5432/jansdb

VM Installations#

For the Janssen Server installed on a VM, a new parameter or parameters with override values can be added either at the global level for all modules or specific to certain modules only. The steps below show how to override the DB connection URI:

Globally For All Modules#

Define environment variable at the VM level, such as shown in the example below:

export CONNECTION_URI=jdbc:postgresql://localhost:5432/jansdb

This will affect all Janssen Server modules, where properties like connection.uri or connection-uri will be overridden with the new value.

Module Specific#

Properties can also be added/overridden at the module level as well. To do this, pass new values either as JVM parameters or as environment variables at the module level.

Janssen Server module level configuration is stored under /etc/default/ directory which contains config files for Janssen modules. For example /etc/default/jans-auth file contains configuration for jans-auth module.

Update the JAVA_OPTIONS parameter to add the value of the new connection URI against the connection.uri parameter. For example:
```
-Dconnection.uri=jdbc:postgresql://localhost:5432/jansdb`
```
Using the environment variable, export a new variable, as shown in the example below:
```
export CONNECTION_URI=jdbc:postgresql://localhost:5432/jansdb
```
The exported variable above, CONNECTION_URI, will override the value provided by connection.uri or connection-uri parameters.

Architecture#

Jans ORM has modular architecture. The are few layers in this implementation

jans-orm-core: This is base layer with next functionality:
- define API methods to work with DB without specific DB dependency
- provide base implementation with reusable parts needed for DB modules implementation
- scan beans and work with ORM layer annotations
jans-orm-annotation: Define annotations which instruct ORM about how to work with beans and properties
jans-orm-filter: This module provides Filter API. The syntax is very similar to LDAP filters. The ORM layer converts them at runtime to DB query syntax: SQL/NoSQL/LDAP
jans-orm-cdi: Provides reusable factory which can be used in CDI based projects
jans-orm-standalone: Provides reusable factory for non CDI based application
jans-orm-ldap, jans-orm-couchbase, jans-orm-spanner, jans-orm-sql: These are DB specific implementations.

Sample table and ORM API#

In order to work with DB ORM layer should know which data (attributes/columns) is needed for application. Most part of this information it takes from DB schema at startup but rest of it developer should define in java bean. Here is typical schema with comments:

// Specify that this is Table/objectClass structure
@DataEntry
// Table/objectClass name is `jansPerson`
@ObjectClass(value = "jansPerson")
public class SimpleUser implements Serializable {

    private static final long serialVersionUID = -1634191420188575733L;

    // Define entry primary key. In LDAP terminology it's DN
    @DN
    private String dn;

    // Define text attribute with name in DB `uid`.
    // Consistency attribute instruct ORM that it should send query to DB and
    // specify that it should execute it after table index update.
    // This is used with Couchbase DB
    @AttributeName(name = "uid", consistency = true)
    private String userId;

    // Define date/time attribute with name in DB `updatedAt`
    @AttributeName
    private Date updatedAt;

    // Define date/time attribute with name in DB `jansCreationTimestamp`
    @AttributeName(name = "jansCreationTimestamp")
    private Date createdAt;

    // Define multivalued text attribute with name in DB `jansPersistentJWT`
    @AttributeName(name = "jansPersistentJWT")
    private String[] oxAuthPersistentJwt;


    // All attributes which not defined above ORM should put into the List<CustomObjectAttribute>
    // This is convenient for custom attributes
    @AttributesList(name = "name", value = "values", multiValued = "multiValued", sortByName = true)
    protected List<CustomObjectAttribute> customAttributes = new ArrayList<CustomObjectAttribute>();

    // Specify additional objecClass
    // This is needed for LDAP only
    @CustomObjectClass
    private String[] customObjectClasses;

    ...

Main PersistenceEntryManager API methods which applications can use:

    <T> boolean authenticate(String primaryKey, Class<T> entryClass, String password);
    <T> boolean authenticate(String baseDN, Class<T> entryClass, String userName, String password);

    void persist(Object entry);
    void merge(Object entry);

    <T> boolean contains(String primaryKey, Class<T> entryClass);
    <T> boolean contains(String primaryKey, Class<T> entryClass, Filter filter);

    <T> int countEntries(Object entry);
    <T> int countEntries(String primaryKey, Class<T> entryClass, Filter filter);
    <T> int countEntries(String primaryKey, Class<T> entryClass, Filter filter, SearchScope scope);

    <T> T find(Object primaryKey, Class<T> entryClass, String[] ldapReturnAttributes);

    <T> List<T> findEntries(Object entry);
    <T> List<T> findEntries(Object entry, int count);

    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter);
    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter, int count);
    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter, String[] ldapReturnAttributes);
    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter, String[] ldapReturnAttributes, int count);
    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter, SearchScope scope, String[] ldapReturnAttributes,
                            int start, int count, int chunkSize);
    <T> List<T> findEntries(String primaryKey, Class<T> entryClass, Filter filter, SearchScope scope, String[] ldapReturnAttributes,
                            BatchOperation<T> batchOperation, int start, int count, int chunkSize);

    <T> PagedResult<T> findPagedEntries(String primaryKey, Class<T> entryClass, Filter filter, String[] ldapReturnAttributes, String sortBy,
                                        SortOrder sortOrder, int start, int count, int chunkSize);

    void remove(Object entry);

    <T> void removeByDn(String dn, String[] objectClasses);
    <T> void remove(String primaryKey, Class<T> entryClass);

    <T> int remove(String primaryKey, Class<T> entryClass, Filter filter, int count);

    <T> void removeRecursively(String primaryKey, Class<T> entryClass);
    <T> void removeRecursivelyFromDn(String primaryKey, String[] objectClasses);

    boolean hasBranchesSupport(String primaryKey);
    boolean hasExpirationSupport(String primaryKey);

    String getPersistenceType();
    String getPersistenceType(String primaryKey);

    Date decodeTime(String primaryKey, String date);
    String encodeTime(String primaryKey, Date date);

    int getHashCode(Object entry);

    <T> List<AttributeData> exportEntry(String dn, String objectClass);

    <T> void importEntry(String dn, Class<T> entryClass, List<AttributeData> data);

New DB support and integrations#

The ORM developed with perspective to simplify to add new DB support. New ORM implementation requires only few classes/interfaces implementations.

Extend public interface DbOperationService extends PersistenceOperationService interface to define list of CRUD method which DbEntryManager can use.
Implement abstract methods DbEntryManager extends BaseEntryManager<DbOperationService>. This define DB specific methods to work with DB low layer.
Implement public class DbEntryManagerFactory implements PersistenceEntryManagerFactory. This CDI @ApplicationScoped needed to allow integrate new DB module into application.
Put into final jar file /META-INF/beans.xml to allow CDI framework automatically find DbEntryManagerFactory from previous point.

After this it's enough to put new ORM DB module into application war file or follow customization sections to add jar file to custom jetty classpath.

DB Schema#

The DB schema and beans definitions should match each other. During deployment setup generates schema and indexes based on rules in schema file. The data types defined in it setup map to DB SQL types based on default rules.

It's possible to override default generation rules. For this case there is next file.

Default indexes defined in next files: coubase_index.json, spanner_index.json, mysql_index.json, pgsql_index.json

Last update: 2024-03-01
Created: 2022-09-02