feat: Add functionality to the Opentelemetry write interface to extract fields from attr to top-level data.

src/frontend/src/instance/otlp.rs

@@ -114,7 +114,6 @@ impl OpenTelemetryProtocolHandler for Instance {
             .get::<OpenTelemetryProtocolInterceptorRef<servers::error::Error>>();
         interceptor_ref.pre_execute(ctx.clone())?;
         let (requests, rows) = otlp::logs::to_grpc_insert_requests(request, pipeline, table_name)?;
-
         self.handle_log_inserts(requests, ctx)
             .await
             .inspect(|_| OTLP_LOGS_ROWS.inc_by(rows as u64))

src/pipeline/src/etl.rs

@@ -317,8 +317,33 @@ pub(crate) fn find_key_index(intermediate_keys: &[String], key: &str, kind: &str
         .context(IntermediateKeyIndexSnafu { kind, key })
 }
 
+/// SelectInfo is used to store the selected keys from OpenTelemetry record attrs
+#[derive(Default)]
+pub struct SelectInfo {
+    pub keys: Vec<String>,
+}
+
+/// Try to convert a string to SelectInfo
+/// The string should be a comma-separated list of keys
+/// example: "key1,key2,key3"
+/// The keys will be sorted and deduplicated
+impl From<String> for SelectInfo {
+    fn from(value: String) -> Self {
+        let mut keys: Vec<String> = value.split(',').map(|s| s.to_string()).sorted().collect();
+        keys.dedup();
+
+        SelectInfo { keys }
+    }
+}
+
+impl SelectInfo {
+    pub fn is_empty(&self) -> bool {
+        self.keys.is_empty()
+    }
+}
+
 pub enum PipelineWay {
-    Identity,
+    OtlpLog(Box<SelectInfo>),
     Custom(std::sync::Arc<Pipeline<crate::GreptimeTransformer>>),
 }
 

src/pipeline/src/etl/transform/transformer/greptime.rs

@@ -207,11 +207,11 @@ impl Transformer for GreptimeTransformer {
 /// As you traverse the user input JSON, this will change.
 /// It will record a superset of all user input schemas.
 #[derive(Debug, Default)]
-struct SchemaInfo {
+pub struct SchemaInfo {
     /// schema info
-    schema: Vec<ColumnSchema>,
+    pub schema: Vec<ColumnSchema>,
     /// index of the column name
-    index: HashMap<String, usize>,
+    pub index: HashMap<String, usize>,
 }
 
 fn resolve_schema(

src/pipeline/src/lib.rs

@@ -18,10 +18,11 @@ mod metrics;
 
 pub use etl::error::Result;
 pub use etl::processor::Processor;
+pub use etl::transform::transformer::greptime::SchemaInfo;
 pub use etl::transform::transformer::identity_pipeline;
 pub use etl::transform::{GreptimeTransformer, Transformer};
 pub use etl::value::{Array, Map, Value};
-pub use etl::{error as etl_error, parse, Content, Pipeline, PipelineWay};
+pub use etl::{error as etl_error, parse, Content, Pipeline, PipelineWay, SelectInfo};
 pub use manager::{
     error, pipeline_operator, table, util, PipelineInfo, PipelineRef, PipelineTableRef,
     PipelineVersion,

src/servers/src/error.rs

@@ -538,6 +538,12 @@ pub enum Error {
         #[snafu(implicit)]
         location: Location,
     },
+    #[snafu(display("OpenTelemetry select key {} is complicated structure.", key))]
+    OpenTelemetryNestValueIsComplicated {
+        key: String,
+        #[snafu(implicit)]
+        location: Location,
+    },
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
@@ -603,7 +609,8 @@ impl ErrorExt for Error {
             | ParseJson { .. }
             | UnsupportedContentType { .. }
             | TimestampOverflow { .. }
-            | OpenTelemetryLog { .. } => StatusCode::InvalidArguments,
+            | OpenTelemetryLog { .. }
+            | OpenTelemetryNestValueIsComplicated { .. } => StatusCode::InvalidArguments,
 
             Catalog { source, .. } => source.status_code(),
             RowWriter { source, .. } => source.status_code(),

src/servers/src/http/header.rs

@@ -47,6 +47,7 @@ pub mod constants {
     pub const GREPTIME_LOG_PIPELINE_NAME_HEADER_NAME: &str = "x-greptime-log-pipeline-name";
     pub const GREPTIME_LOG_PIPELINE_VERSION_HEADER_NAME: &str = "x-greptime-log-pipeline-version";
     pub const GREPTIME_LOG_TABLE_NAME_HEADER_NAME: &str = "x-greptime-log-table-name";
+    pub const GREPTIME_LOG_EXTRACT_KEYS_HEADER_NAME: &str = "x-greptime-log-extract-keys";
 }
 
 pub static GREPTIME_DB_HEADER_FORMAT: HeaderName =

src/servers/src/http/otlp.rs

@@ -34,11 +34,12 @@ use opentelemetry_proto::tonic::collector::trace::v1::{
     ExportTraceServiceRequest, ExportTraceServiceResponse,
 };
 use pipeline::util::to_pipeline_version;
-use pipeline::PipelineWay;
+use pipeline::{PipelineWay, SelectInfo};
 use prost::Message;
 use session::context::{Channel, QueryContext};
 use snafu::prelude::*;
 
+use super::header::constants::GREPTIME_LOG_EXTRACT_KEYS_HEADER_NAME;
 use super::header::{write_cost_header_map, CONTENT_TYPE_PROTOBUF};
 use crate::error::{self, Result};
 use crate::http::header::constants::{
@@ -181,13 +182,41 @@ where
     }
 }
 
+pub struct SelectInfoWrapper(SelectInfo);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for SelectInfoWrapper
+where
+    S: Send + Sync,
+{
+    type Rejection = (StatusCode, String);
+
+    async fn from_request_parts(parts: &mut Parts, _state: &S) -> StdResult<Self, Self::Rejection> {
+        let select = parts.headers.get(GREPTIME_LOG_EXTRACT_KEYS_HEADER_NAME);
+
+        match select {
+            Some(name) => {
+                let select_header =
+                    pipeline_header_error(name, GREPTIME_LOG_EXTRACT_KEYS_HEADER_NAME)?;
+                if select_header.is_empty() {
+                    Ok(SelectInfoWrapper(Default::default()))
+                } else {
+                    Ok(SelectInfoWrapper(SelectInfo::from(select_header)))
+                }
+            }
+            None => Ok(SelectInfoWrapper(Default::default())),
+        }
+    }
+}
+
 #[axum_macros::debug_handler]
-#[tracing::instrument(skip_all, fields(protocol = "otlp", request_type = "traces"))]
+#[tracing::instrument(skip_all, fields(protocol = "otlp", request_type = "logs"))]
 pub async fn logs(
     State(handler): State<OpenTelemetryProtocolHandlerRef>,
     Extension(mut query_ctx): Extension<QueryContext>,
     pipeline_info: PipelineInfo,
     table_info: TableInfo,
+    SelectInfoWrapper(select_info): SelectInfoWrapper,
     bytes: Bytes,
 ) -> Result<OtlpResponse<ExportLogsServiceResponse>> {
     let db = query_ctx.get_db_string();
@@ -218,7 +247,7 @@ pub async fn logs(
         };
         pipeline_way = PipelineWay::Custom(pipeline);
     } else {
-        pipeline_way = PipelineWay::Identity;
+        pipeline_way = PipelineWay::OtlpLog(Box::new(select_info));
     }
 
     handler