vector/transforms/
trace_to_log.rs

1use vector_lib::config::clone_input_definitions;
2use vector_lib::configurable::configurable_component;
3
4use crate::config::OutputId;
5use crate::{
6    config::{DataType, GenerateConfig, Input, TransformConfig, TransformContext, TransformOutput},
7    event::{Event, LogEvent},
8    schema::Definition,
9    transforms::{FunctionTransform, OutputBuffer, Transform},
10};
11
12/// Configuration for the `trace_to_log` transform.
13///
14/// This is a naive implementation that simply converts a `TraceEvent` to a `LogEvent`.
15/// The conversion preserves all trace attributes (span IDs, trace IDs, etc.) as log fields without modification.
16/// This will need to be updated when Vector's trace data model is finalized to properly handle trace-specific semantics and field mappings.
17#[configurable_component(transform("trace_to_log", "Convert trace events to log events."))]
18#[derive(Clone, Debug, Default)]
19#[serde(deny_unknown_fields)]
20pub struct TraceToLogConfig {
21    /// The namespace to use for logs. This overrides the global setting.
22    #[serde(default)]
23    #[configurable(metadata(docs::hidden))]
24    pub log_namespace: Option<bool>,
25}
26
27impl GenerateConfig for TraceToLogConfig {
28    fn generate_config() -> toml::Value {
29        toml::Value::try_from(Self {
30            log_namespace: None,
31        })
32        .unwrap()
33    }
34}
35
36#[async_trait::async_trait]
37#[typetag::serde(name = "trace_to_log")]
38impl TransformConfig for TraceToLogConfig {
39    async fn build(&self, _context: &TransformContext) -> crate::Result<Transform> {
40        Ok(Transform::function(TraceToLog))
41    }
42
43    fn enable_concurrency(&self) -> bool {
44        true
45    }
46
47    fn input(&self) -> Input {
48        Input::trace()
49    }
50
51    fn outputs(
52        &self,
53        _: &TransformContext,
54        input_definitions: &[(OutputId, Definition)],
55    ) -> Vec<TransformOutput> {
56        vec![TransformOutput::new(
57            DataType::Log,
58            clone_input_definitions(input_definitions),
59        )]
60    }
61}
62
63#[derive(Clone, Debug)]
64pub struct TraceToLog;
65
66impl FunctionTransform for TraceToLog {
67    fn transform(&mut self, output: &mut OutputBuffer, event: Event) {
68        if let Event::Trace(trace) = event {
69            output.push(Event::Log(LogEvent::from(trace)));
70        }
71    }
72}
73
74#[cfg(test)]
75mod tests {
76    use super::*;
77    use crate::test_util::components::assert_transform_compliance;
78    use crate::transforms::test::create_topology;
79    use tokio::sync::mpsc;
80    use tokio_stream::wrappers::ReceiverStream;
81    use vector_lib::event::TraceEvent;
82
83    #[test]
84    fn generate_config() {
85        crate::test_util::test_generate_config::<TraceToLogConfig>();
86    }
87
88    async fn do_transform(trace: TraceEvent) -> Option<LogEvent> {
89        assert_transform_compliance(async move {
90            let config = TraceToLogConfig {
91                log_namespace: Some(false),
92            };
93            let (tx, rx) = mpsc::channel(1);
94            let (topology, mut out) = create_topology(ReceiverStream::new(rx), config).await;
95
96            tx.send(trace.into()).await.unwrap();
97
98            let result = out.recv().await;
99
100            drop(tx);
101            topology.stop().await;
102            assert_eq!(out.recv().await, None);
103
104            result
105        })
106        .await
107        .map(|e| e.into_log())
108    }
109
110    #[tokio::test]
111    async fn transform_trace() {
112        use vrl::btreemap;
113
114        let trace = TraceEvent::from(btreemap! {
115            "span_id" => "abc123",
116            "trace_id" => "xyz789",
117            "span_name" => "test-span",
118            "service" => "my-service",
119        });
120
121        let (expected_map, _) = trace.clone().into_parts();
122
123        let log = do_transform(trace).await.unwrap();
124        let (actual_value, _) = log.into_parts();
125        let actual_map = actual_value
126            .into_object()
127            .expect("log value should be an object");
128
129        assert_eq!(
130            actual_map, expected_map,
131            "Trace data fields should be preserved"
132        );
133    }
134}
vector/transforms/trace_to_log.rs

vector/transforms/
trace_to_log.rs
