Update declaratvie config jaeger remote sampler to require endpoint, initial_sampler (#7943)

Author: jack-berg

sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/SamplerFactoryTest.java

@@ -129,6 +129,29 @@ private static Stream<Arguments> createArguments() {
                 .build()));
   }
 
+  @ParameterizedTest
+  @MethodSource("createInvalidArguments")
+  void createInvalid(SamplerModel model, String expectedMessage) {
+    assertThatThrownBy(() -> SamplerFactory.getInstance().create(model, context))
+        .isInstanceOf(DeclarativeConfigException.class)
+        .cause()
+        .hasMessage(expectedMessage);
+  }
+
+  private static Stream<Arguments> createInvalidArguments() {
+    return Stream.of(
+        Arguments.of(
+            new SamplerModel()
+                .withJaegerRemoteDevelopment(new ExperimentalJaegerRemoteSamplerModel()),
+            "jaeger remote sampler endpoint is required"),
+        Arguments.of(
+            new SamplerModel()
+                .withJaegerRemoteDevelopment(
+                    new ExperimentalJaegerRemoteSamplerModel()
+                        .withEndpoint("http://jaeger-remote-endpoint")),
+            "jaeger remote sampler initial_sampler is required"));
+  }
+
   @Test
   void create_SpiExporter_Unknown() {
     List<Closeable> closeables = new ArrayList<>();

sdk-extensions/jaeger-remote-sampler/src/main/java/io/opentelemetry/sdk/extension/trace/jaeger/sampler/internal/JaegerRemoteSamplerComponentProvider.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.sdk.extension.trace.jaeger.sampler.internal;
 
+import io.opentelemetry.api.incubator.config.DeclarativeConfigException;
 import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider;
 import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfiguration;
@@ -34,20 +35,22 @@ public String getName() {
   public Sampler create(DeclarativeConfigProperties config) {
     JaegerRemoteSamplerBuilder builder = JaegerRemoteSampler.builder();
 
-    // Optional configuration
     String endpoint = config.getString("endpoint");
-    if (endpoint != null) {
-      builder.setEndpoint(endpoint);
+    if (endpoint == null) {
+      throw new DeclarativeConfigException("jaeger remote sampler endpoint is required");
     }
+    builder.setEndpoint(endpoint);
+
+    DeclarativeConfigProperties initialSamplerModel = config.getStructured("initial_sampler");
+    if (initialSamplerModel == null) {
+      throw new DeclarativeConfigException("jaeger remote sampler initial_sampler is required");
+    }
+    builder.setInitialSampler(DeclarativeConfiguration.createSampler(initialSamplerModel));
+
     Long pollingIntervalMs = config.getLong("internal");
     if (pollingIntervalMs != null) {
       builder.setPollingInterval(Duration.ofMillis(pollingIntervalMs));
     }
-    DeclarativeConfigProperties initialSamplerModel = config.getStructured("initial_sampler");
-    if (initialSamplerModel != null) {
-      Sampler initialSampler = DeclarativeConfiguration.createSampler(initialSamplerModel);
-      builder.setInitialSampler(initialSampler);
-    }
 
     return builder.build();
   }