Tag: MicroProfile

Categories
MicroProfile Project setup

MicroProfile support for Jessie

Introduction

In some previous blog, I introduced Jessie, a tool for creating maven based applications which contain the skeleton for applications using Java EE, DeltaSpike, PrimeFaces, and Octopus (the declarative security framework for Java EE)

Although most people just copy and paste from an existing application, I find it very handy that I can generate very easily some as I create quite some demo type applications.

The last few months, besides Java EE applications, I’m also creating more and more Eclipse MicroProfile based demos. So in the last few weeks, I added support for MicroProfile into Jessie. It generates a demo app which uses the MicroProfile Specifications and specific support for the different server implementations.

MicroProfile 1.2

Version 1.2 is not the latest version of the specification. It is released end of September 2017 but is supported by quite a number of implementations as you can see on this overview page.

Besides the basic buildings blocks JAX-RS, JSON-P, and CDI, it contains

Configuration

This specification defines how configuration values can be read from different sources to customize your application.

Fault tolerance

It defines some various options for resilient micro-services like retry policies, bulkheads, circuit breakers, and fallback options.

JWT Authentication

This first version defines the basics of authentication and authorization information propagation to the micro-service using JWT. Inspired on OAuth2 and OpenId Connect, it is possible to define user information and the roles it has in a self-contained way so that no external parties need to be consulted.

Health Metrics

It defines the way how developers can expose some ‘telemetry’ data in a uniform way. It has support for things like the number of invocations, statistics on the execution time of endpoints, and so on.

Health Checks

The health checks are on a different level as the metrics. Which the checks we can verify if our service is still performing well. Or that we should kill it and start a new one. Besides standard checks (using memory, CPU, etc …) you can define your own checks very easily.

Application Generation

In this first version, the generation is still at a basic level. The online version of Jessie can be found here.

After you have selected the ‘MicroProfile’ technology stack, added some basic information about the maven artifact name, you can select one of the 4 implementations that support MicroProfile 1.2 completely

– WildFly swarm – 2017.12.1
– Liberty 17.0.0.3
– KumuluzEE 2.5.2
– Payara micro 5.181

The app contains examples of all specifications mentioned above (the JWT auth code is not always completely working due to small issues in configuration and calling the endpoint) and can be seen in action from the index.html overview page.

Conclusion

In this second official release of Jessie, you can now also generate MicroProfile 1.2 applications. You can choose one of the 4 supported implementations and all the required code for generating a fat jar application is in place.

In a future version of Jessie, newer releases of MicroProfile will be supported, the small known issues will be handled and selection of the included specifications will be possible.

have fun.

Categories
Atbash Overview

Atbash repositories overview

Now that I’m working a bit more than 6 months on the Atbash repositories, it is time to give you some overview of them.

For the moment, almost all of them are geared towards Java EE 7 and Java 7.

The idea is to create a MicroProfile compatible experience on Java EE 7. As much as possible of course. Since MicroProfile is based on Java 8, it is not always easy (or possible) to have an identical experience.

But the idea is to give the developers the possibility to have a “smooth” migration from Java EE 7 to MicroProfile by having all or the most important specifications, available on those servers.

Utility repository

Github

This contains some code used in multiple other Atbash repositories. It is not directly related to the goal but can have some usages in any project.

utils-se

– BASE64 encoder and decoder
– Utility class related to searching classes and resources on different class loaders (Current Thread, class loader of utility class or System class loader) and instantiating classes with advanced argument matching.
– Reading library or framework version from manifest file
– Check to see if an application is running within a CDI container
– Utilities related to verification and handling proxies (like determining original class)

– Reflection utilities useable in unit testing (so that we can read and set private properties without the need for setters and getters which would only be needed for testing)

utils-cdi

– Programmatic retrieval of CDI Beans, also for an optional bean (bean defined by Producer method which may or may not be present)
– Retrieval of a bean defined by Producer method involving generic types (issue due to type erasure)

– Fake bean manager useable within unit tests to supply some Mock Cdi bean instances when using programmatic CDI bean retrieval.

utils-jsf

– Creating a method expression based on the expression value
– Retrieving property values from JSF components (taking into account expressions and static values)
– Custom component finding which starts at the parent itself but then extends to the parent until found or view root is reached.

Atbash JSON (Java SE)

GitHub

Alternative JSON-B implementation (not following the specs!) to convert Java instances to JSON and vice versa. The code is adapted from the JSON smart framework (no longer maintained) for the use cases within Atbash (see Atbash JWT support) and extended to have customizations.

JWT Support (Java SE + CDI)

GitHub

The code in this repository is to support JWT (JSON Web Token, signed but also encrypted) as they appear in protocols like OAuth2 and OpenId Connect.

To support this encoding and decoding, there is also a unified handling of cryptographic keys. It is capable of reading them from a PEM file, a Java Keystore, a JWK and a JWKSet. Various encrypted formats for the Private Key are supported.

But the idea goes a bit further than just support OpenId Connect JWTs. Instead of exchanging data as JSON, why not exchange them as JWT. That way, we are not only transferring information but also make some guarantees like sender verification and end to end protection as we can detect changes through the signing.

Atbash Config (Java SE + CDI)

GitHub

The Atbash config is a Java 7 port of the MicroProfile Config specification and the Apache Geronimo implementation.

But there are also some extensions created like
– Support for custom named configuration files.
– Support for Stages so that based on a system property, values can be overridden in environments like Test environment.
– Support for custom formatted date values
– Logging of configuration values at startup of the application.
– Support for YAML format.

There is also a Config provider for testing available where the configuration values are stored in a HashMap.

Atbash Config server (MicroProfile Product)

GitHub

Allows defining the configuration values for MicroProfile application in a central place. These applications can retrieve the values using a JAX-RS endpoint.

There is also a client implementation available which, when added to the application, retrieves the values automatically, based on the configured endpoint of the config server.

Jerry (JSF)

GitHub

Jerry defines a JSF Renderer interceptor which allows you to perform various tasks on any JSF component.

It is the basis for a more advanced validation mechanism for JSF and the declarative security features of Octopus for JSF components.

Valerie (JSF, Bean Validation)

GitHub

Using the interceptor mechanism of Jerry, Valerie places the validation constraints of the Java properties (like not null, length etc) automatically on the JSF components it uses.
This way it allows to have the visual aspects of these constraints on the JSF component HTML representation and JSF validation without the need to put these constraints as JSF attribute values.

Octopus (Java SE, Java FX, CDI, JSF, JAX-RS)

GitHub

Octopus is a large framework consisting of small artifacts that bring you every aspect of authentication and authorization for Java EE and MicroProfile applications.

  • Permission-based framework
  • Secures URL, JSF components, and CDI and EJB method calls
  • Support for Java SE, JavaFX, JAX-RS and JSF
  • Integrates with OAuth2, OpenId Connect, LDAP, database, JWT, KeyCloak, CAS, …
  • Custom OpenId Connect solution within a microservices environment
  • Compatible with (and using) Microprofile (Config, Rest Client, MP-JWT, …), Java EE Security API, …
  • Very flexible, can be easily integrated within your application
  • Tightly integrated with CDI
  • Type-safe definition of permissions
  • Declarative declaration of JSF security (with tags, not using rendered attribute)
  • A custom voter can be created for more complex security requirements

Dependencies overview

The following Neo4J graph gives you an overview of the dependencies between these repositories and the relation with other libraries. Octopus is left out of the image because it would complicate it too much.

Have fun

Categories
Configuration MicroProfile

Atbash Configuration Server

Introduction

MicroProfile Config specification defines how configuration values can be picked up by the application. It has the concept of a Configuration source and converters to supply the values you need.

By default, only a ConfigSource for a classpath defined file and environment and system variables are defined.

But since we have the concepts in place, we can create our custom ConfigSource to retrieve the configuration from a central server.

Configuration Server

Instead of putting the configuration of each application within the application itself, we can store it in a central location.

It is very convenient to have an overview of the configuration of all your application at one place. Which makes updating it also very simple.

The first version of the Atbash Configuration Server exposes the configuration of an application through a JAX-RS endpoint.

The URL

/config/{application}

will give you the configuration values as a JSON structure for the specified application.

{
   "pets":"dog,cat",
   "dateValue":"2017-11-15",
   "value2":"500",
   "classname":"be.atbash.config.examples.se.testclasses.ConvTestTypeWStringCt",
   "value1":"Classpath Value",
   "value3":"true",
   "dateValueFmt":"16-11-2017,dd-MM-yyyy"
}

Creating the Configuration server

The configuration server is available within the directory  <server> of the repository https://github.com/atbashEE/atbash-config-server

You can build the server in 3 flavors

1. Java EE war.

With the maven command, mvn package -Pee7-servera WAR file is created which can be run by any Java EE 7 compliant server (Java 8 required)

2. WildFly Swarm executable JAR

The Configuration server can also be wrapped within a WildFly swarm application with the mvn package -Pwildfly-swarmcommand.

3. WebSphere Liberty executable JAR

There is also a profile defined to create a WebSphere Liberty JAR file, use the mvn package -Plibertycommand.

More servers will be supported when they have support for Config Spec 1.2.

Configuration of Server

Define within a config-server.properties or config-sever.yaml file on the classpath the following configuration information.

– rootDirectory: Root directory containing the configuration files for the application. See further for a directory structure.

– applications: List of known applications.

example (as yaml)

rootDirectory : /Users/rubus/atbash/config-server/server/demo
applications : ["app1", "app2"]

Possible directory structure

/demo
├── /app1
│  ├── app1.properties
│  └── app1-test.properties
└── /app2
   └── app2.properties

A subdirectory for each application so that the configuration values are nicely separated for each application.

All the features of Atbash config (like stage, yaml support, date support, etc) are available.

Client configuration

A ConfigSource implementation is available which integrates the result of the call to the JAX-RS endpoint into the configuration of the application.

In this first version, Atbash configuration extension is required (which makes it a bit more work) but this requirement will be removed in the next version.

Add the Maven artifact to your dependencies

    <dependency>
        <groupId>be.atbash.config</groupId>
        <artifactId>atbash-config-client</artifactId>
        <version>${atbash-config.version}</version>
    </dependency>

Define the base name of the configuration file which contains the configuration of the Config server.

Create a class implementing the be.atbash.config.spi.BaseConfigurationName interface and defining this class for usage with the ServiceLoader mechanism of Java.

Define the class name within src/main/resources/META-INF/services/be.atbash.config.spi.BaseConfigurationName

be.atbash.config.examples.DemoBaseName

Define the configuration within the specified properties file.

config.server.url=http://localhost:8181
config.server.app=app1
config.server.stage=test

* config.server.url: The _root_ of the Config server endpoint.

* config.server.app: The name of your application

* config.server.stage: (optional) Indication of the stage of the application to retrieve specific values.

We can use all the regular features of Configuration or Atbash config to specify the stage value, like environment or system properties.

The client can be used in a Java SE, Java EE or a MicroProfile environment.

Conclusion

With the Atbash Configuration server, you can store the configuration values for all your applications at a central location. The values can be picked up by a JAX-RS call through the Client ConfigSource.

The server can be run by WildFly Swarm, Liberty or a regular Java EE 7 server. The client can be used for all environments capable of using the MicroProfile Configuration spec (including Java SE and Java EE)

A future version will bring you some more features and makes it easier to set things up.

Have fun.

Categories
Configuration

Implicit converters for MicroProfile Config

Introduction

Last month (January 2018), an update of the MicroProfile Config specification, version 1.2, was released which makes it easier to convert the configuration values to class instances.
It adds the concept of implicit/automatic converters and removes the requirement for creating specific converters in many cases.
The first implementations are already available and Atbash Configuration is now also updated.
This blog describes what the implicit/automatic converters are and how you can use them.

Converters

The configuration values we define are Strings because they are defined as a set of Characters in the configuration files. Using the configuration could be limited to a system which is capable of reading those Strings and that the developers need to convert these values to the proper instance (like Integer, Boolean or application specific classes) themselves.
But in that case, each developer will write his own set of converters and in the case of Integers and Booleans, for example, they are all the same.
So the framework itself can take care of these converters. And since we have then already the concept of a convert, it is easy to foresee an SPI which allows the creation of custom Converters by the developer for their application specific classes.
These basic converters for Integer and Boolean for example where present since the first release of the spec. Just as the SPI to add your own converters.

Implicit Converters

But the creation of all those custom converters can be minimized further. Since our application specific classes can be created from a String, they probably have some means of instantiating them through a method which takes a String parameter
– The constructor
– A static method with names like valueOf or parse.
So with the new implicit/automatic converters feature, when we have some class like this
public class ClassWithStringConstructor {
    private String value;

    public ClassWithStringConstructor (String value) {
        this.value = value;
    }

    public String getValue() {
        return value;
    }
}
and have a parameter
some.key = Atbash

We can retrieve an instance of the class, with the value using

config.getValue("some.key", ClassWithStringConstructor.class)

or when we are in a CDI enabled context, we can also use injection

@Inject
@ConfigProperty("some.key")
private ClassWithStringConstructor parameterValue;

Collection type parameters

Another nice addition to this 1.2 release, is the use of collection type parameters. The ability to have multiple parameter values, like a list of values which is converted to an Array, List or Set.
It is quite common that a configuration value is, in fact, a list of value.
pets = dog,cat
previously, the developer needed to split the String and use the individual parts separately (although this is a very simple task with String.split() ), can be done automatically.
config.getValue("pets", String[].class)

With injection, we can automatically convert it to a List or a Set.

@Inject
@ConfigProperty(name = "pets")
private List<String> pets;

The List and Set variants can’t be used in a programmatic way (using config.getValue) since the second parameter doesn’t accept parameterized types (like List<String>).

When you have a value which contains a comma it in, you need to escape it
a,b,c\\,d

which results in 3 configuration values, where the last one is c,d.

Implicit combined with Collection.

We can even combine the collection type feature with the implicit/automatic converter feature. If we instead specify the class name like ClassWithStringConstructor instead of String, the configuration framework will use the appropriate way of converting.
config.getValue("pets", ClassWithStringConstructor[].class)

or

@Inject
@ConfigProperty(name = "pets")
private List<ClassWithStringConstructor> pets;

Octopus Config

As you could read in a previous blog, Octopus Config is a Java 7 port from Geronimo config. The support for the implicit/automatic converters and collections (like the arrays, List, and set) is taken from them.
Octopus Config itself is also updated so that the YAML usage supports the Collection type parameters. The example above with the pets can be written in the YAML equivalent format as
pets: [dog , cat]

The release 0.9.1 contains also some small other features are listed here. Most notable features are

– Improved Class converters based on different classloaders.
– Test artefact.
– Logging in Java SE environment
– Improvement information in logging with @ModuleConfigName
– Compatibility with another MicroProfile Config implementation on Java 8.

Conclusion

With the addition of the implicit/automatic converters, the need for writing custom converters can be dropped and conversion will take place by convention.
The Octopus Config version v0.9.1 is updated to incorporate these features together with some small other improvements and fixes.
Have fun.

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