We have a microservice architecture with one of the microservices having a Spring Batch job which processes a CSV file and calling another microservice. Both microservices are OAuth2 protected ResourceServers. When we call the first microservice, a batch job is started and we want the Authorization header to be passed to the second microservice. The solution can be defined as:
In a Feign RequestInterceptor, grab the current OAuth access_token and pass it on the the RequestTemplate with Hystrix running in SEMAPHORE execution isolation strategy
|
1 2 3 4 5 6 7 8 9 10 11 |
@SpringBootApplication @EnableDiscoveryClient @EnableFeignClients @EnableResourceServer @EnableOAuth2Client public class MyApplication { public static void main(String[] args) { SpringApplication.run(MyApplication .class, args); } } |
Define Job execution
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
@RestController @RequiredArgsController public class RunMyJobController { private final JobLauncher jobLauncher; private final Job myJob; private final OAuth2ClientContext oauth2ClientContext; @RequestMapping(method = RequestMethod.POST) public void startJob() { JobParametersBuilder parametersBuilder = new JobParametersBuilder(); //Run the job. JobExecution jobExecution = jobLauncher.run(myJob, parametersBuilder.toJobParameters()); //Here you can evaluate the job result and //send the proper return to the client. } } |
RequestInterceptor
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 |
@Configuration @ComponentScan @EnableBatchProcessing public class MyBatchConfig{ //Your jobRepository and job configuration goes here. @Bean public ItemProcessor<?, ?> myItemProcessor(MyFeignClient myFeignClient) { return (item) -> myFeignClient.postItem(item); } @Bean public RequestInterceptor oauth2BatchRequestInterceptor(OAuth2ClientContext oauth2ClientContext) { //This is where we grab the access_token //And set is on the feign RequestTemplate return (template) -> template.header(HttpHeaders.AUTHORIZATION, String.format("%s %s", oauth2ClientContext.getAccessToken().getTokenType(), oauth2ClientContext.getAccessToken().getValue() ) ); } } |
Hystrix isolation strategy
Now we set the default isolation strategy of hystrix to SEMAPHORE. Otherwise we will get an error:
Method threw 'org.springframework.beans.factory.BeanCreationException' exception.... Scope 'session' is not active for the current thread;
|
1 2 |
//Prevent hystrix from running (feign) in isolation strategy THREAD. See <a href="https://github.com/Netflix/Hystrix/wiki/Configuration#execution.isolation.strategy">https://github.com/Netflix/Hystrix/wiki/Configuration#execution.isolation.strategy</a> hystrix.command.default.execution.isolation.strategy: SEMAPHORE |