chore: support and use the default http/protobuf protocol

refs #503 (comment)

Author: smoke

javaagent-log-appender/README.md

@@ -39,7 +39,6 @@ In a separate shell, run the application
 ```shell
 export \
 OTEL_SERVICE_NAME=log4j-example \
-OTEL_EXPORTER_OTLP_PROTOCOL=grpc \
 OTEL_METRICS_EXPORTER=none \
 OTEL_TRACES_EXPORTER=none \
 OTEL_LOGS_EXPORTER=otlp
@@ -48,3 +47,8 @@ OTEL_LOGS_EXPORTER=otlp
 ```
 
 Watch the collector logs to see exported log records
+
+NOTE: The OpenTelemetry Java Agent uses `http/protobuf` by default, optionally switch to use `grpc` protocol
+```shell
+export OTEL_EXPORTER_OTLP_PROTOCOL=grpc
+```

javaagent-log-appender/build.gradle.kts

@@ -33,7 +33,7 @@ dependencies {
     implementation("io.opentelemetry:opentelemetry-api")
     implementation("io.opentelemetry.semconv:opentelemetry-semconv")
 
-    // OpenTelemetry JavaAgent, this brings its own standalone log4j / logback appenders
+    // OpenTelemetry Java Agent, this brings its own standalone log4j / logback appenders
     agent("io.opentelemetry.javaagent:opentelemetry-javaagent:2.8.0")
 }
 

javaagent-log-appender/docker-compose.yml

@@ -7,3 +7,4 @@ services:
     command: ["--config=/otel-config.yaml"]
     ports:
       - "4317:4317"
+      - "4318:4318"

javaagent-log-appender/otel-config.yaml

@@ -3,18 +3,20 @@ receivers:
     protocols:
       grpc:
         endpoint: collector:4317
+      http:
+        endpoint: "0.0.0.0:4318"
 exporters:
   debug:
     verbosity: detailed
   nop:
 service:
   pipelines:
-    logs:
+    metrics:
       receivers: [otlp]
       exporters: [debug]
     traces:
       receivers: [otlp]
       exporters: [debug]
-    metrics:
+    logs:
       receivers: [otlp]
-      exporters: [nop]
+      exporters: [debug]