4:08 a.m.
Hey guys,
For the past few days I've been wracking my brain trying to come up with
a design for the IDM configuration API that doesn't suck, and allows
easy configuration in both Java SE and EE environments while maintaining
separation between the API and implementation. I think I've come up
with something that's quite flexible and extensible, so I'd like to run
it past everyone for some feedback.
The starting point for configuring the Identity Management API is a
concrete class called IdentityConfiguration:
public class IdentityConfiguration {
private List<IdentityStoreConfiguration> configuredStores = new
ArrayList<IdentityStoreConfiguration>();
public List<IdentityStoreConfiguration> getConfiguredStores() {
return configuredStores;
}
public void addStoreConfiguration(IdentityStoreConfiguration config) {
configuredStores.add(config);
}
}
This class simply provides a holder for one or more
IdentityStoreConfiguration(s), an abstract class that provides the
basics for configuring an IdentityStore:
public abstract class IdentityStoreConfiguration {
private final Map<String,String> properties = new
HashMap<String,String>();
private final Set<Feature> supportedFeatures = new HashSet<Feature>();
public Set<Feature> getSupportedFeatures() {
return supportedFeatures;
}
public void addSupportedFeature(Feature feature) {
supportedFeatures.add(feature);
}
public void removeSupportedFeature(Feature feature) {
supportedFeatures.remove(feature);
}
public void setProperty(String name, String value) {
properties.put(name, value);
}
public String getPropertyValue(String name) {
return properties.get(name);
}
}
Each IdentityStore implementation (such as JPAIdentityStore,
LDAPIdentityStore, etc) should have a corresponding
IdentityStoreConfiguration implementation that provides an API for
setting specific property values for its IdentityStore. For example,
this is the one for JPAIdentityStore which allows a number of entity
classes to be set:
public class JPAIdentityStoreConfiguration extends
IdentityStoreConfiguration {
private Class<?> identityClass;
private Class<?> membershipClass;
private Class<?> credentialClass;
private Class<?> attributeClass;
public Class<?> getIdentityClass() {
return identityClass;
}
public void setIdentityClass(Class<?> identityClass) {
this.identityClass = identityClass;
}
public Class<?> getCredentialClass() {
return credentialClass;
}
public void setCredentialClass(Class<?> credentialClass) {
this.credentialClass = credentialClass;
}
public Class<?> getMembershipClass() {
return membershipClass;
}
public void setMembershipClass(Class<?> membershipClass) {
this.membershipClass = membershipClass;
}
public Class<?> getAttributeClass() {
return attributeClass;
}
public void setAttributeClass(Class<?> attributeClass) {
this.attributeClass = attributeClass;
}
}
The IdentityStore-specific configurations are intended to be part of the
API, so they should be placed in the API module within the
org.picketlink.idm.config package.
After creating an IdentityConfiguration, you can create an
IdentityManager and provide the configuration via the bootstrap() method:
IdentityConfiguration identityConfig = new IdentityConfiguration();
JPAIdentityStoreConfiguration storeConfig = new
JPAIdentityStoreConfiguration();
// snip storeConfig configuration
identityConfig.addStoreConfiguration(storeConfig);
IdentityManager identityManager = new DefaultIdentityManager();
identityManager.bootstrap(identityConfig, new
DefaultIdentityStoreInvocationContextFactory(null));
The reason we use bootstrap() instead of performing configuration in the
constructor is so the developer has a chance to override the
IdentityStoreFactory. This is an SPI interface that defines a couple of
methods which are used to control which IdentityStoreConfigurations
correspond to which IdentityStore.
public interface IdentityStoreFactory {
/**
* Creates an instance of an IdentityStore using the provided
configuration
*
* @param config
* @return
*/
IdentityStore createIdentityStore(IdentityStoreConfiguration config);
/**
* Maps specific implementations of IdentityStoreConfiguration to a
corresponding
* IdentityStore implementation.
*
* @param configClass
* @param storeClass
*/
void mapConfiguration(Class<? extends IdentityStoreConfiguration>
configClass,
Class<? extends IdentityStore> storeClass);
}
By default, the DefaultIdentityManager will create and use an instance
of DefaultIdentityStoreFactory - this factory knows about all the
built-in IdentityStore implementations and can create IdentityStore
instances based on their corresponding IdentityStoreConfiguration. If a
developer wished to provide their own IdentityStore though (or override
the behaviour of one of the built-in ones) then we need to provide a
hook to allow them to override the default factory with their own. This
is provided by the IdentityManager.setIdentityStoreFactory() method - by
invoking this method with a new IdentityStoreFactory the developer can
provide an alternative factory for creating IdentityStore instances
based on non built-in configurations before bootstrap() is called.
Here's an example where the built-in identity stores are supplemented
with support for a native Hibernate-based identity store:
IdentityManager identityManager = new DefaultIdentityManager();
DefaultIdentityStoreFactory factory = new DefaultIdentityStoreFactory();
factory.mapConfiguration(HibernateIdentityStoreConfiguration.class,
HibernateIdentityStore.class);
identityManager.setIdentityStoreFactory(factory);
identityManager.bootstrap(identityConfig, new
DefaultIdentityStoreInvocationContextFactory(null));
The last piece of the puzzle is the second parameter to the bootstrap()
method. This parameter should be an instance of
IdentityStoreInvocationContextFactory (I know, it's a mouthful), an SPI
interface that declares a single method:
public interface IdentityStoreInvocationContextFactory {
IdentityStoreInvocationContext getContext(IdentityStore store);
}
The implementation of this interface is responsible for creating
IdentityStoreInvocationContext instances, which are passed as a
parameter value to pretty much all of the IdentityStore methods and
allow the IdentityStore implementation to be shared between multiple
threads (i.e. a stateless design). The IdentityStoreInvocationContext
is responsible for providing the IdentityStore with any state (besides
the IdentityStore configuration) required to execute its requested
operation. It also provides a gateway to the event bridge, which allows
events to be raised during an IdentityStore operation and propagated to
any environment, such as the CDI event bus. The
IdentityStoreInvocationContext implementation/s are currently still a
work in progress, however the basic API should not change.
This essentially wraps up the description of the configuration API. What
I haven't touched upon yet are the builders (classes that parse a
configuration source such as a file to create an
IdentityStoreConfiguration) however I'm hoping Anil that you might want
to have a go at this.
With these changes comes a small TO-DO list:
1) IdentityStoreConfiguration implementations should be created in the
API module within the org.picketlink.idm.config package for each of the
IdentityStore implementations (we already have one for LDAP, but it
needs to be moved and possibly renamed to LDAPIdentityStoreConfiguration
for consistency).
2) During the course of the refactor I had to provide workarounds for
many of the tests, and I also managed to totally break quite a few
others. The test suite needs a quick review to see why the tests are
broken, and once configurations are provided for the other identity
stores the workarounds can be removed.
3) The getFeatureSet() method should be correctly implemented for all
IdentityStores. With the change to the configuration API we now have
proper support for partitioning, and it's important that this method
accurately reflect the underlying capabilities of the IdentityStore
implementation for this feature to work correctly.
Thanks for listening, and I'm looking forward to getting some feedback
on this!
Shane