GrpcTracing bean cannot be injected at startup
dimi-nk opened this issue · 7 comments
Describe the bug
I've recently introduced distributed tracing into one of our projects with the use of spring sleuth. Brave defines a GrpcTracing class which can create a ClientInterceptor via #newClientInterceptor. GrpcTracing is provided by TraceGrpcAutoConfiguration.
Since LogNet/grpc-spring-boot-starter doesn't include a mechanism to define global ClientInterceptors (as it does with @GRpcGlobalInterceptor), I created a small piece of code that gathers all provided ClientInterceptors and attaches them to gRPC channels.
So, for example, I'd want to provide brave's TracingClientInterceptor doing the following:
@Bean
@ConditionalOnBean(GrpcTracing.class)
public ClientInterceptor grpcTracingClientInterceptor(GrpcTracing grpcTracing) {
return grpcTracing.newClientInterceptor();
}We have tracing disabled in the dev and test profiles, so GrpcTracing won't be available. Hence the conditional.
Then, a simplified version of my implementation would be the following (the problem is in the block above so I don't think going into too much details here matters):
@Bean
public FooServiceBlockingStub fooServiceStub(List<ClientInterceptor> clientInterceptors) {
return xyz; // create channel and stub
}Now... When I use @ConditionalOnBean(GrpcTracing.class), the ClientInterceptor is never created. Even when adding a breakpoint, it doesn't stop. Even weirder, when I use the condition TraceGrpcAutoConfiguration#grpcTracing doesn't execute either... RpcTracing gets created every time. If I remove the condition, both configurations load. If I inject Optional<GrpcTracing> both configurations work.
I tried @AutoConfigureAfter(TraceGrpcAutoConfiguration.class) on my configuration class but it didn't work either. IIRC, user configurations run after auto-configurations anyway 🤷♂️ . I'm struggling to see why GrpcTracing is not available during start-up. I don't have any other conditions on the configuration class or method. I checked all conditions on TraceGrpcAutoConfiguration and they are all met.
I'm at my wits' end. Do you have any idea why this doesn't work 👀 ?
In case it helps, this is the current version of my configuration class.
@Configuration
@AutoConfigureAfter(TraceGrpcAutoConfiguration.class)
public class TracingConfiguration {
private final Map<String, String> commonTags;
public TracingConfiguration(@Value("${git.commit.id:unknown}") String gitCommitId) {
var commonTags = new HashMap<String, String>();
commonTags.put("service.version", gitCommitId);
EnvironmentMetadata.create()
.toAttributes()
.forEach((key, value) -> commonTags.put(key, valueToString(value)));
this.commonTags = Map.copyOf(commonTags);
}
private static String valueToString(AttributeValue value) {
return value.match(
s -> s, Object::toString, Object::toString, Object::toString, Object::toString);
}
@Bean
ClientInterceptor grpcClientInterceptor(Optional<GrpcTracing> grpcTracing) {
return grpcTracing.map(GrpcTracing::newClientInterceptor).orElse(null);
}
@Bean
SpanHandler commonTagsHandler() {
return new SpanHandler() {
@Override
public boolean end(TraceContext traceContext, MutableSpan span, Cause cause) {
if (cause == Cause.FINISHED) {
commonTags.forEach(span::tag);
}
return true; // keep this span
}
};
}
/**
* Create a propagation factory chain. Stackdriver always delegates first before resolving itself.
* gRPC always tries to extract <code>grpc-trace-bin</code> otherwise delegates. B3 tries to
* resolve.
*
* <p>Therefore, the chain of resolution is the first that manages to extract a context from
* <code>grpc-trace-bin</code>, <code>B3</code>, and <code>X-Cloud-Trace-Context</code>.
*/
@Bean
FactoryBuilder customPropagationFactoryBuilder() {
return BaggagePropagation.newFactoryBuilder(
StackdriverTracePropagation.newFactory(new CustomPropagationFactory()));
}
private static class CustomPropagationFactory extends Factory {
@Override
public <K> Propagation<K> create(Propagation.KeyFactory<K> keyFactory) {
return StringPropagationAdapter.create(this.get(), keyFactory);
}
@Override
public Propagation<String> get() {
return GrpcPropagation.create(B3Propagation.get());
}
}
}The slightly more complicated version of the global client interceptor looks like the following. The only thing it does it take all provided client interceptors and pass them through include/exlude filters defined in properties.
@RequiredArgsConstructor
public class PropertyBasedGlobalClientInterceptorLoader implements GlobalClientInterceptorLoader {
private final GrpcProperties properties;
private final List<ClientInterceptor> injectedInterceptors;
@Override
public List<ClientInterceptor> globalInterceptors() {
var interceptorFilters = properties.getClient().getGlobalInterceptors();
if (interceptorFilters.getInclude().size() > 0) {
return injectedInterceptors.stream()
.filter(i -> interceptorFilters.getInclude().contains(i.getClass()))
.collect(toList());
} else if (interceptorFilters.getExclude().size() > 0) {
return injectedInterceptors.stream()
.filter(not(i -> interceptorFilters.getExclude().contains(i.getClass())))
.collect(toList());
} else {
return injectedInterceptors;
}
}
}and
@Configuration
@EnableConfigurationProperties(GrpcProperties.class)
public class GrpcChannelAutoConfiguration {
@Bean
public DomainResolver domainResolver() {
return new DomainResolver();
}
@Bean
@ConditionalOnMissingBean
public GrpcChannelResolver channelResolver(
DomainResolver domainResolver, Optional<GlobalClientInterceptorLoader> interceptorLoader) {
return new DefaultGrpcChannelResolver(
interceptorLoader.map(GlobalClientInterceptorLoader::globalInterceptors).orElse(List.of()),
domainResolver);
}
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(
value = "acme.grpc.client.global-interceptors.enabled",
havingValue = "true",
matchIfMissing = true)
public GlobalClientInterceptorLoader clientInterceptorLoader(
GrpcProperties properties, Optional<List<ClientInterceptor>> injectedInterceptors) {
return new PropertyBasedGlobalClientInterceptorLoader(
properties, injectedInterceptors.orElse(List.of()));
}
}Can you upload this a sample that we can check out?
I think you should go with @AutoConfigureAfter(TraceGrpcAutoConfiguration.class) but you would have to register your own configuration as autoconfiguration in spring.factories (I don't see that file in your repo). Can you try adding this
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
your.package.YouCustomAutoConfigurationin the src/main/resources/META-INF/spring.factories file and try again with the latest version of Sleuth?
@marcingrzejszczak hmm I didn't realise @AutoConfigureAfter doesn't work on non-autoconfiguration classes, this could be it. Is there some documentation on when to use @AutoConfigureBefore|After? I assumed spring calculated the object graph and determined the sequence of beans it needs to create.
@dimi-nk Yes, there are some docs around this topic:
- The whole section of Auto-configuration is very useful
- javadoc of the
org.springframework.boot.autoconfigurepackage
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