Relocate dependencies in the generated shadowJar

[psx95]

This updates the exporter-auto build config to be able to generate both - shaded and non-shaded versions of the dependency.

Testing

• ./gradlew build generates non-shaded version. (slim-JAR)
• ./gradlew shadowJar generates uberJar with shaded (relocated) dependencies.
• Ran the autoconf and autoinstrument examples with the updated JARs - both ran successfully.
  • autoinstrument - Traces are being generated; Metrics have a known issue - #149

Notes

• The maven publish plugin would have to be configured to release both artifacts. [TODO]
• The conscrypt plugin is intentionally not shaded - see this comment.

• The source classes are also erroneously relocated to the shadow prefix, i.e. com/google/cloud/opentelemetry/auto/*.class → shadow/com/google/cloud/opentelemetry/auto/*.class

  While this is unconventional, it has not caused any issue in running the examples or cause other test failures. It could be argued that moving the source classes to a shaded path prevents users from accidentally accessing these classes and could also prevent ambiguity in-case both shaded and non-shaded versions of this dependency end up on the same classpath (even though this would most likely be an error and should not be done).

[psx95]

The scoped work for this PR is complete, however while using the shaded auto exporter for the auto-instrument example, I noticed that the metrics were failing. with error -

com.google.api.gax.rpc.InternalException: io.grpc.StatusRuntimeException: INTERNAL: http2 exception
    at com.google.api.gax.rpc.ApiExceptionFactory.createException(ApiExceptionFactory.java:67)
    at com.google.api.gax.grpc.GrpcApiExceptionFactory.create(GrpcApiExceptionFactory.java:72)
    at com.google.api.gax.grpc.GrpcApiExceptionFactory.create(GrpcApiExceptionFactory.java:60)
    at com.google.api.gax.grpc.GrpcExceptionCallable$ExceptionTransformingFuture.onFailure(GrpcExceptionCallable.java:97)
    at com.google.api.core.ApiFutures$1.onFailure(ApiFutures.java:68)
    at com.google.common.util.concurrent.Futures$CallbackListener.run(Futures.java:1074)
    at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:30)
    at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1213)
    at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:983)
    at com.google.common.util.concurrent.AbstractFuture.setException(AbstractFuture.java:771)
    at io.grpc.stub.ClientCalls$GrpcFuture.setException(ClientCalls.java:563)
    at io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:533)
    at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:553)
    at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:68)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:739)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:718)
    at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
    at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:829)
    Suppressed: com.google.api.gax.rpc.AsyncTaskException: Asynchronous task failed
        at com.google.api.gax.rpc.ApiExceptions.callAndTranslateApiException(ApiExceptions.java:57)
        at com.google.api.gax.rpc.UnaryCallable.call(UnaryCallable.java:112)
        at com.google.cloud.monitoring.v3.MetricServiceClient.createTimeSeries(MetricServiceClient.java:1526)
        at com.google.cloud.monitoring.v3.MetricServiceClient.createTimeSeries(MetricServiceClient.java:1469)
        at com.google.cloud.opentelemetry.metric.CloudMetricClientImpl.createTimeSeries(CloudMetricClientImpl.java:40)
        at com.google.cloud.opentelemetry.metric.GoogleCloudMetricExporter.createTimeSeriesBatch(GoogleCloudMetricExporter.java:221)
        at com.google.cloud.opentelemetry.metric.GoogleCloudMetricExporter.export(GoogleCloudMetricExporter.java:206)
        at io.opentelemetry.sdk.metrics.export.PeriodicMetricReader$Scheduled.doRun(PeriodicMetricReader.java:142)
        at io.opentelemetry.sdk.metrics.export.PeriodicMetricReader$Scheduled.run(PeriodicMetricReader.java:128)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305)
        at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        ... 1 more
Caused by: io.grpc.StatusRuntimeException: INTERNAL: http2 exception
    at io.grpc.Status.asRuntimeException(Status.java:535)
    ... 10 more
Caused by: io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2Exception$HeaderListSizeException: Header size exceeded max allowed size (8192)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2Exception.headerListSizeError(Http2Exception.java:189)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2CodecUtil.headerListSizeExceeded(Http2CodecUtil.java:233)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.HpackDecoder$Http2HeadersSink.finish(HpackDecoder.java:546)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.HpackDecoder.decode(HpackDecoder.java:133)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2HeadersDecoder.decodeHeaders(DefaultHttp2HeadersDecoder.java:126)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2FrameReader$HeadersBlockBuilder.headers(DefaultHttp2FrameReader.java:743)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2FrameReader$2.processFragment(DefaultHttp2FrameReader.java:483)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2FrameReader.readHeadersFrame(DefaultHttp2FrameReader.java:491)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:254)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:174)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:378)
    at io.grpc.netty.shaded.io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:501)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:440)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
    at io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1526)
    at io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1275)
    at io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1322)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:501)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:440)
    at io.grpc.netty.shaded.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
    at io.grpc.netty.shaded.io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
    at io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
    at io.grpc.netty.shaded.io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
    at io.grpc.netty.shaded.io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
    at io.grpc.netty.shaded.io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:475)
    at io.grpc.netty.shaded.io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
    at io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
    at io.grpc.netty.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.grpc.netty.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    ... 1 more

This error is not introduced through this PR, but apparently has been there for quite some time. I code at commit - c4085c5223eca5b1dbe400b2554a6274bb494a4c (Made on Jan 23, 2023) also has this issue.

Update:

This is already a known issue when running in a GKE environment - #149, so out of scope for this PR. Verified that Java auto-instrumentation works with auto-exporter in a non-GKE (local) environment.