basic

Basic authentication against embedded engine example

This example demonstrates how to perform following steps:

• configure embedded engine to run in spring-boot application
• configure REST API to run in spring-boot application
• configure basic authentication on REST API in spring-boot
• perform a request towards API protected with Basic Authentication

Why is this example interesting?

This example illustrates how to start spring boot application with embedded engine and REST API available as well as basic authentication filter.

Show me the important parts!

Add basic spring applicationContext.xml with your engine configuration.

  <bean id="processEngineConfiguration"
    class="org.camunda.bpm.engine.spring.SpringProcessEngineConfiguration">
    <property name="processEngineName" value="default" />
    <property name="dataSource" ref="dataSource" />
    <property name="transactionManager" ref="transactionManager" />
    <property name="databaseSchemaUpdate" value="true" />
    <property name="jobExecutorActivate" value="false" />
    <property name="deploymentResources" value="classpath*:*.bpmn" />
    <property name="metricsEnabled" value="false"/>
  </bean>

  <bean id="processEngine" class="org.camunda.bpm.engine.spring.ProcessEngineFactoryBean">
    <property name="processEngineConfiguration" ref="processEngineConfiguration" />
  </bean>

  <bean id="repositoryService" factory-bean="processEngine"
    factory-method="getRepositoryService" />
  <bean id="runtimeService" factory-bean="processEngine"
    factory-method="getRuntimeService" />
  <bean id="taskService" factory-bean="processEngine"
    factory-method="getTaskService" />
  <bean id="historyService" factory-bean="processEngine"
    factory-method="getHistoryService" />
  <bean id="managementService" factory-bean="processEngine"
    factory-method="getManagementService" />
  <bean id="identityService" factory-bean="processEngine"
        factory-method="getIdentityService" />

A custom JAX-RS Application class deploys the REST Endpoints:

public class RestProcessEngineDeployment extends Application {

  @Override
  public Set<Class<?>> getClasses() {
    Set<Class<?>> classes = new HashSet<Class<?>>();

    classes.addAll(CamundaRestResources.getResourceClasses());
    classes.addAll(CamundaRestResources.getConfigurationClasses());

    return classes;
  }

}

Implement the REST Process Engine Provider SPI (provides the process engine to the REST application):

public class RestProcessEngineProvider implements ProcessEngineProvider {

  public ProcessEngine getDefaultProcessEngine() {
    return ProcessEngines.getDefaultProcessEngine();
  }

  public ProcessEngine getProcessEngine(String name) {
    return ProcessEngines.getProcessEngine(name);
  }

  public Set<String> getProcessEngineNames() {
    return ProcessEngines.getProcessEngines().keySet();
  }

}

Add a file named:

`src/main/resources/META-INF/services/org.camunda.bpm.engine.rest.spi.ProcessEngineProvider`

which contains the name of the provider:

`org.camunda.bpm.example.authentication.rest.RestProcessEngineProvider`

Add maven dependencies:

<!-- spring boot -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
    <groupId>org.camunda.bpm</groupId>
    <artifactId>camunda-engine</artifactId>
</dependency>

<dependency>
    <groupId>org.camunda.bpm</groupId>
    <artifactId>camunda-engine-spring</artifactId>
</dependency>

<dependency>
    <groupId>org.camunda.bpm</groupId>
    <artifactId>camunda-engine-rest</artifactId>
    <classifier>classes</classifier>
</dependency>

<dependency>
    <groupId>org.jboss.resteasy</groupId>
    <artifactId>resteasy-jaxrs</artifactId>
    <version>3.0.8.Final</version>
</dependency>

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.3.171</version>
</dependency>

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>${spring.version}</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>

Configure your spring boot application to instantiate all required filters and import engine beans from separate xml based context file.

@SpringBootApplication
@Configuration
@ImportResource("classpath*:applicationContext.xml")
public class CamundaSpringBootExampleApplication extends SpringBootServletInitializer {
	private static final String EMAIL = "demo@camunda.org";

	@Autowired
	private IdentityService identityService;

	@PostConstruct
	public void initDemoUser() {
		User newUser = identityService.newUser("demo");
		newUser.setPassword("demo");
		newUser.setEmail(EMAIL);
		identityService.saveUser(newUser);
	}

	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
		return configureApplication(builder);
	}

	public static void main(String[] args) {
		configureApplication(new SpringApplicationBuilder()).run(args);
	}

	private static SpringApplicationBuilder configureApplication(SpringApplicationBuilder builder) {
		return builder.sources(CamundaSpringBootExampleApplication.class).bannerMode(Banner.Mode.OFF);
	}

	@Bean
	public FilterRegistrationBean authenticationFilter() {
		FilterRegistrationBean registration = new FilterRegistrationBean();
		Filter myFilter = new ProcessEngineAuthenticationFilter();
		registration.setFilter(myFilter);
		registration.addUrlPatterns("/*");
		registration.addInitParameter("authentication-provider","org.camunda.bpm.engine.rest.security.auth.impl.HttpBasicAuthenticationProvider");
		registration.setName("camunda-auth");
		registration.setOrder(1);
		return registration;
	}

	@Bean
	public FilterRegistrationBean restEasyFilter() {
		FilterRegistrationBean registration = new FilterRegistrationBean();
		Filter myFilter = new FilterDispatcher();
		registration.setFilter(myFilter);
		registration.addUrlPatterns("/*");
		registration.addInitParameter("javax.ws.rs.Application","org.camunda.bpm.example.authentication.rest.RestProcessEngineDeployment");
		registration.setName("Resteasy");
		registration.setOrder(10);
		return registration;
	}
	
}

How to use it?

You can either build it with maven and see that tests are executed successfully, or you can run CamundaSpringBootExampleApplication class as a Java application, and try to open following url in your browser http://localhost:8080/engine/default/user. Which will request username and password from you. If you use demo\demo as your authentication data, you should see information of demo user in JSON format printed to your screen.