The objective of this project is to provide a "simple" example to access a Java Microservice using the Open Source Identity and Access Management Keycloak and JavaWebToken (JWT).
We want to ...
... secure the Microservice with Authentication​
... secure a specific REST Endpoint invocation of the Microservice with Authorization​
... test the access to the Microservice with a JUnit test.
The Microservice runs on OpenLiberty and uses MicroProfile. The example Microservice is called Authors
and is from the open sourced Cloud Native Starter project.The example doesn't use a frontend UI for the Authentication. The JUnit test will authenticate with the Keycloak REST API.
Here is a 7 minutes YouTube video about the setup of the example.
​​​​
The Authors
Microservice application supports a protected login with JWT and the specific REST call getAuthors
is protected by a specific user role. The image below contains a simplified architecture overview of the example which runs on the local machine, here you see:
The JUnit
test and Authors Microservice are running on a OpenLiberty
server
The Authors
Microservice is build with MicroProfile
The needed JWT
Key is saved on the OpenLiberty server in the Authors
Microservice using MicroProfile configuration​
The JUnit
test requests a bearer token
to access the Authors
service
The major configuration information inside Keycloak
Note: In this example Keycloak server is available on localhost:8282 and Authors Microservice on OpenLiberty runs on localhost:3000.
A very simplified overview of the test execution to access Authors
Microservice using Keycloak
, OpenLiberty
, MicroProfile
and JWT
, is shown in the sequence diagram below.
Start the JUnit
test called Test_GetAuthors
. The test invokes the private operation getToken
.
Request a bearer token from Keycloak
using a REST Endpoint (http://localhost:8282/auth/realms/protocol/openid-connect/token). The request contains the needed Keycloak data for the authorization as parameters to get the bearer token
.
formData.param("username", user).param("password", password).param("realm", realm).param("grant_type", grant_type).param("client_id", client_id);
That bearer token
does contain the Java Web Token
, which is protected with the RS256 (RSA Signature with SHA-256)
. RS256
is a JWT signing algorithm.
Proceeding with the test by invoking the private operation getAuthorAuthorized
.
Now the Authors
REST Endpoint (http://localhost:3000/api/v1/getAuthor) is invoked using the bearer token we got from Keycloak, which contains the JWT. The JWT does contain all needed information such as user, role and soon.
Verifying the JWT by the Authors
Microservice application, that will be done automatically,, by using the given RS256 signed Key
for the JWT in our Microservice application on the OpenLiberty
server. When the provided Key is validated, the JWT can be used to access the REST Endpoint of the Authors Microservice.
Now the Endpoint validates, does the JavaWebToken
contain the right role to access the information?
Then the response data data will be compared with the expected value.
​Keycloak​
For the setup of Keycloak we need ...
... run a local Keycloak Docker image
... add a realm​
... import an existing realm configuration with:
Realm Keys
Client definition
Role and Group definition
Groups role mapping
... create a user and add him to the existing group with the role to add the Microservice
​OpenLiberty and MicroProfile​
For the setup of the Java Microservice with OpenLiberty and MicroProfile with the JUnit test, it's useful to understand the steps from the blog post "Write and execute a JUnit test for a Java Microservice based on MicroProfile and run both in the OpenLiberty development mode".
We need to ...
... configure the server.xml
of OpenLiberty
... add login and security functionality to the AuthorsApplication
class
... secure the REST Endpoint in the GetAuthor
class
​JUnit test​
We need to ...
... use the two-factor authentication to access the Authors
Microservice
... use a REST a client to send the requests to the Authors
Microservice and Keycloak
... verify Authors
Microservice response in the JUnit test
​Jakarta EE​
​MicroProfile​
​OpenLiberty​
​Keycloak​
​JUnit​
​Java Web Token​
​Docker​
​Keycloak​
This project has been created by using following technical environment:
Development environment:
​Docker Desktop: version 2.3
​MacOS:: 10.15.5 OS Catalina
​Visual Studio Code with the Java extension Pack​
Java project:
​OpenLiberty: version 20.0.0.6
​Keycloak: version 9.0.2
​MicroProfile: version 3.2
​Glassfish: version 1.1
​yasson: version 1.0
​JUnit: version 5.6.0
​OpenLiberty Maven Plugin: version 3.1
​Apache Maven Compiler Plugin: version 3.1
​Maven Surefire Plugin: version 2.22.2
​Apache CXF MicroProfile Client: version 3.3.1
​Maven Java Compiler:: version 1.8