flagd and test containers

[joe-chambers]

Has anyone gotten flagd to run with testcontainers (specifically with springboot) in Java?

My POM.xml ->

        <dependency>
            <groupId>dev.openfeature</groupId>
            <artifactId>sdk</artifactId>
            <version>${open-feature-sdk.version}</version>
        </dependency>

        <dependency>
            <groupId>dev.openfeature.contrib.providers</groupId>
            <artifactId>flagd</artifactId>
            <version>${open-feature-provider-flagd.version}</version>
            <scope>compile</scope>
        </dependency>

My declaration:

  @Bean
//  @ServiceConnection("flagd")
  @SuppressWarnings("resource")
  Container<?> flagdContainer() {
    return new GenericContainer<>(DockerImageName.
        parse("ghcr.io/open-feature/flagd")
          .withTag("v0.12.8"))
        .withLogConsumer(new Slf4jLogConsumer(LoggerFactory.getLogger("com.example.springbootflagd.integrationtests.testcontainers.Flagd")))
        .withCommand("start", "--uri",
            "https://raw.githubusercontent.com/open-feature/flagd/main/samples/example_flags.flagd.json")
        .withExposedPorts(8013, 8014);
  }

I always get the following error:

2025-09-07T13:55:12.599-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 
2025-09-07T13:55:12.599-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		 ______   __       ________   _______    ______      
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		/_____/\ /_/\     /_______/\ /______/\  /_____/\     
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		\::::_\/_\:\ \    \::: _  \ \\::::__\/__\:::_ \ \    
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		 \:\/___/\\:\ \    \::(_)  \ \\:\ /____/\\:\ \ \ \   
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		  \:::._\/ \:\ \____\:: __  \ \\:\\_  _\/ \:\ \ \ \  
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		   \:\ \    \:\/___/\\:.\ \  \ \\:\_\ \ \  \:\/.:| | 
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 		    \_\/     \_____\/ \__\/\__\/ \_____\/   \____/_/ 
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDOUT: 
2025-09-07T13:55:12.600-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDERR: 2025-09-07T17:55:12.611Z	info	cmd/start.go:140	flagd version: v0.12.8 (c0a2940aef33f8558aa6ea4941ded74f0a6f6e83), built at: 2025-07-23	{"component": "start"}
2025-09-07T13:55:12.601-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDERR: 2025-09-07T17:55:12.611Z	info	flag-sync/sync_service.go:96	starting flag sync service on port 8015	{"component": "FlagSyncService"}
2025-09-07T13:55:12.607-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDERR: 2025-09-07T17:55:12.619Z	info	ofrep/ofrep_service.go:58	ofrep service listening at 8016	{"component": "OFREPService"}
2025-09-07T13:55:12.609-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDERR: 2025-09-07T17:55:12.620Z	info	flag-evaluation/connect_service.go:231	Flag IResolver listening at [::]:8013	{"component": "service"}
2025-09-07T13:55:12.609-04:00  INFO 11974 --- [tream-738457623] c.e.s.i.testcontainers.Flagd             : STDERR: 2025-09-07T17:55:12.619Z	info	flag-evaluation/connect_service.go:251	metrics and probes listening at 8014	{"component": "service"}
2025-09-07T13:55:12.688-04:00  WARN 11974 --- [ntainers-wait-0] .c.w.i.InternalCommandPortListeningCheck : An exception while executing the internal check: Container.ExecResult(exitCode=126, stdout=OCI runtime exec failed: exec failed: unable to start container process: exec: "/bin/sh": stat /bin/sh: no such file or directory: unknown
, stderr=)
2025-09-07T13:55:12.688-04:00  INFO 11974 --- [           main] tc.ghcr.io/open-feature/flagd:v0.12.8    : Container ghcr.io/open-feature/flagd:v0.12.8 started in PT0.586809S
2025-09-07T13:55:13.039-04:00  INFO 11974 --- [           main] c.e.s.integrationtests.Application       : Started Application in 3.246 seconds (process running for 3.994)
2025-09-07T13:55:13.044-04:00  INFO 11974 --- [       Thread-7] d.o.sdk.FeatureProviderStateManager      : Provider flagd transitioned from state NOT_READY to state ERROR
2025-09-07T13:55:13.044-04:00 ERROR 11974 --- [       Thread-7] dev.openfeature.sdk.ProviderRepository   : Exception when initializing feature provider dev.openfeature.contrib.providers.flagd.FlagdProvider

java.lang.IllegalStateException: Already shut down
	at dev.openfeature.contrib.providers.flagd.FlagdProviderSyncResources.waitForInitialization(FlagdProviderSyncResources.java:83) ~[flagd-0.11.4.jar:na]
	at dev.openfeature.contrib.providers.flagd.FlagdProvider.initialize(FlagdProvider.java:130) ~[flagd-0.11.4.jar:na]
	at dev.openfeature.sdk.FeatureProviderStateManager.initialize(FeatureProviderStateManager.java:26) ~[sdk-1.17.0.jar:na]
	at dev.openfeature.sdk.ProviderRepository.initializeProvider(ProviderRepository.java:213) ~[sdk-1.17.0.jar:na]
	at dev.openfeature.sdk.ProviderRepository.lambda$prepareAndInitializeProvider$2(ProviderRepository.java:187) ~[sdk-1.17.0.jar:na]
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[na:na]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

2025-09-07T13:55:13.075-04:00  INFO 11974 --- [ault-executor-1] d.o.c.providers.flagd.FlagdProvider      : FlagdProviderEvent event PROVIDER_ERROR 
2025-09-07T13:55:13.076-04:00  INFO 11974 --- [ault-executor-1] d.o.c.providers.flagd.FlagdProvider      : Connection lost. Emit STALE event...

Not sure why it thinks the container has shutdown.

[aepfli]

can you provide your configuration for the flagd provider? if you only expose the ports, they get randomly assigned to host ports - hence maybe this is causing the issue. We are using test containers also for testing the flagd provider in our e2e tests.

2025-09-07T13:55:12.688-04:00  WARN 11974 --- [ntainers-wait-0] .c.w.i.InternalCommandPortListeningCheck : An exception while executing the internal check: Container.ExecResult(exitCode=126, stdout=OCI runtime exec failed: exec failed: unable to start container process: exec: "/bin/sh": stat /bin/sh: no such file or directory: unknown

Seems like there is maybe also some other issue with the port listening check :)

[joe-chambers]

The FlagdProvider and OpenFeatureAPI are declared in a spring-configuration file:

  @Bean
  @ConditionalOnClass(FlagdProvider.class)
  @ConditionalOnMissingBean(FlagdProvider.class)
  public FlagdProvider flagdProvider(FlagdConnectionDetails flagdConnectionDetails) {
    Assert.hasText(flagdConnectionDetails.getHost(),  "FlagdConnectionDetails.host must not be empty");

    logger.info("building a flagd provider with connection details: <{}>", flagdConnectionDetails);
    FlagdOptionsBuilder flagdOptionsBuilder = FlagdOptions.builder();
    flagdOptionsBuilder.host(flagdConnectionDetails.getHost());
    flagdOptionsBuilder.port(flagdConnectionDetails.getPort() > 3000 ? flagdConnectionDetails.getPort() : 8013);

    FlagdOptions options = flagdOptionsBuilder.build();
    logger.info("building a flagd provider with options: <{}>", options);
    return new FlagdProvider(options);
  }

  @Bean
  @ConditionalOnClass(OpenFeatureAPI.class)
  public OpenFeatureAPI openFeatureAPI(FlagdProvider flagdProvider, FlagdProperties flagdProperties) {
    OpenFeatureAPI openFeatureAPI = OpenFeatureAPI.getInstance();
    if (StringUtils.hasText(flagdProperties.getDomainName())) {
      openFeatureAPI.setProvider(flagdProperties.getDomainName(), flagdProvider);
    } else {
      openFeatureAPI.setProvider(flagdProvider);
    }
    return openFeatureAPI;
  }

Thanks

[aepfli]

... And please also how you configure your flag connection details - this in is the most crucial part ;)

[joe-chambers]

pull the host and port from the container in a testcontainers situation, pull it from a properties settings in a non testcontainers situation the default container port is (8013, in a testcontainers situation pull the exposed port a 'la:

  static class FlagdContainerConnectionDetails extends ContainerConnectionDetails<Container<?>> implements FlagdConnectionDetails {

    public FlagdContainerConnectionDetails(ContainerConnectionSource<Container<?>> source) {
      super(source);
    }

    @Override
    public String getHost() {
      return getContainer().getHost();
    }

    @Override
    public int getPort() {
      return getContainer().getMappedPort(FLAGD_EXPOSED_PORT);
    }

    @Override
    public String toString() {
      final StringBuilder sb =
          new StringBuilder("FlagdContainerConnectionDetails{");
      sb.append("host='").append(getHost()).append('\'');
      sb.append(", port=").append(getPort());
      sb.append('}');
      return sb.toString();
    }
  }
}