feat(opentelemetry sink): add gRPC transport support

Cargo.toml

@@ -904,7 +904,7 @@ sinks-mqtt = ["dep:rumqttc"]
 sinks-nats = ["dep:async-nats", "dep:nkeys"]
 sinks-new_relic_logs = ["sinks-http"]
 sinks-new_relic = []
-sinks-opentelemetry = ["sinks-http", "codecs-opentelemetry"]
+sinks-opentelemetry = ["sinks-http", "codecs-opentelemetry", "dep:tonic", "dep:tonic-health", "dep:prost"]
 sinks-papertrail = ["dep:syslog"]
 sinks-prometheus = ["dep:base64", "dep:prost", "vector-lib/prometheus"]
 sinks-postgres = ["dep:sqlx"]
@@ -1025,7 +1025,7 @@ mongodb_metrics-integration-tests = ["sources-mongodb_metrics"]
 mqtt-integration-tests = ["sinks-mqtt", "sources-mqtt"]
 nats-integration-tests = ["sinks-nats", "sources-nats"]
 nginx-integration-tests = ["sources-nginx_metrics"]
-opentelemetry-integration-tests = ["sources-opentelemetry", "dep:prost"]
+opentelemetry-integration-tests = ["sources-opentelemetry", "sinks-opentelemetry", "dep:prost"]
 postgresql_metrics-integration-tests = ["sources-postgresql_metrics"]
 postgres_sink-integration-tests = ["sinks-postgres"]
 prometheus-integration-tests = ["sinks-prometheus", "sources-prometheus", "sinks-influxdb"]

changelog.d/opentelemetry_sink_config.breaking.md

@@ -0,0 +1,49 @@
+Changed the `opentelemetry` sink config fields to remove `protocol.*`. `protocol.type` was replaced
+by `protocol` and all fields previously nested under `protocol` now can be placed in the top level
+configuration.
+
+Before:
+
+```yaml
+sinks:
+  otel_sink:
+    inputs:
+      - in
+    protocol:
+      type: http
+      uri: http://otel-collector-sink:5318/v1/logs
+      method: post
+      encoding:
+        codec: json
+      framing:
+        method: newline_delimited
+      batch:
+        max_events: 1
+      request:
+        headers:
+          content-type: application/json
+```
+
+After:
+
+```yaml
+sinks:
+  otel_sink:
+    inputs:
+      - in
+    type: opentelemetry
+    protocol: http
+    uri: http://otel-collector-sink:5318/v1/logs
+    method: post
+    encoding:
+      codec: json
+    framing:
+      method: newline_delimited
+    batch:
+      max_events: 1
+    request:
+      headers:
+        content-type: application/json
+```
+
+authors: thomasqueirozb

changelog.d/opentelemetry_sink_grpc.feature.md

@@ -0,0 +1,3 @@
+Added gRPC transport support for the `opentelemetry` sink. Configure with `protocol = "grpc"` and set `uri` to your OTLP/gRPC endpoint (e.g. `http://localhost:4317`). Supports TLS and gzip compression.
+
+authors: thomasqueirozb

lib/codecs/src/encoding/format/otlp.rs

@@ -107,9 +107,14 @@ impl Encoder<Event> for OtlpSerializer {
                 } else if log.contains(RESOURCE_METRICS_JSON_FIELD) {
                     // Currently the OTLP metrics are Vector logs (not metrics).
                     self.metrics_descriptor.encode(event, buffer)
+                } else if log.contains(RESOURCE_SPANS_JSON_FIELD) {
+                    // OTLP spans can arrive as Log events when the source is configured
+                    // without use_otlp_decoding.traces = true.
+                    self.traces_descriptor.encode(event, buffer)
                 } else {
                     Err(format!(
-                        "Log event does not contain OTLP top-level fields ({RESOURCE_LOGS_JSON_FIELD} or {RESOURCE_METRICS_JSON_FIELD})",
+                        "Log event does not contain OTLP top-level fields \
+                         ({RESOURCE_LOGS_JSON_FIELD}, {RESOURCE_METRICS_JSON_FIELD}, or {RESOURCE_SPANS_JSON_FIELD})",
                     )
                         .into())
                 }