revert config changes to preserve backwards compatibility

lib/vector-lookup/src/lookup_v2/mod.rs

@@ -4,7 +4,6 @@ pub use optional_path::{OptionalTargetPath, OptionalValuePath};
 use std::fmt;
 use vector_config_macros::configurable_component;
 
-use vector_config::ConfigurableString;
 pub use vrl::path::{
     parse_target_path, parse_value_path, BorrowedSegment, OwnedSegment, OwnedTargetPath,
     OwnedValuePath, PathConcat, PathParseError, PathPrefix, TargetPath, ValuePath,
@@ -65,8 +64,6 @@ impl From<&str> for ConfigValuePath {
 #[serde(try_from = "String", into = "String")]
 pub struct ConfigTargetPath(pub OwnedTargetPath);
 
-impl ConfigurableString for ConfigTargetPath {}
-
 impl fmt::Display for ConfigTargetPath {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.0)

src/transforms/reduce/config.rs

@@ -4,8 +4,10 @@ use std::time::Duration;
 
 use indexmap::IndexMap;
 use serde_with::serde_as;
-use vrl::path::{PathPrefix, TargetPath};
-use vrl::prelude::{Collection, Kind};
+use vrl::path::{parse_target_path, PathPrefix};
+use vrl::prelude::{Collection, KeyString, Kind};
+
+use vector_lib::configurable::configurable_component;
 
 use crate::conditions::AnyCondition;
 use crate::config::{
@@ -15,8 +17,6 @@ use crate::config::{
 use crate::schema::Definition;
 use crate::transforms::reduce::merge_strategy::MergeStrategy;
 use crate::transforms::{reduce::transform::Reduce, Transform};
-use vector_lib::configurable::configurable_component;
-use vector_lib::lookup::lookup_v2::ConfigTargetPath;
 
 /// Configuration for the `reduce` transform.
 #[serde_as]
@@ -85,7 +85,7 @@ pub struct ReduceConfig {
     #[configurable(metadata(
         docs::additional_props_description = "An individual merge strategy."
     ))]
-    pub merge_strategies: IndexMap<ConfigTargetPath, MergeStrategy>,
+    pub merge_strategies: IndexMap<KeyString, MergeStrategy>,
 
     /// A condition used to distinguish the final event of a transaction.
     ///
@@ -137,12 +137,16 @@ impl TransformConfig for ReduceConfig {
 
         let mut schema_definition = merged_definition;
 
-        for (path, merge_strategy) in self.merge_strategies.iter() {
-            let input_kind = match path.prefix() {
-                PathPrefix::Event => schema_definition.event_kind().at_path(path.value_path()),
-                PathPrefix::Metadata => {
-                    schema_definition.metadata_kind().at_path(path.value_path())
-                }
+        for (key, merge_strategy) in self.merge_strategies.iter() {
+            let key = if let Ok(key) = parse_target_path(key) {
+                key
+            } else {
+                continue;
+            };
+
+            let input_kind = match key.prefix {
+                PathPrefix::Event => schema_definition.event_kind().at_path(&key.path),
+                PathPrefix::Metadata => schema_definition.metadata_kind().at_path(&key.path),
             };
 
             let new_kind = match merge_strategy {
@@ -211,7 +215,7 @@ impl TransformConfig for ReduceConfig {
                 new_kind
             };
 
-            schema_definition = schema_definition.with_field(&path.0, new_kind, None);
+            schema_definition = schema_definition.with_field(&key, new_kind, None);
         }
 
         // the same schema definition is used for all inputs

src/transforms/reduce/transform.rs

@@ -14,9 +14,9 @@ use crate::{
 };
 use futures::Stream;
 use indexmap::IndexMap;
-use vector_lib::lookup::lookup_v2::ConfigTargetPath;
 use vector_lib::stream::expiration_map::{map_with_expiration, Emitter};
 use vrl::path::{parse_target_path, OwnedTargetPath};
+use vrl::prelude::KeyString;
 
 #[derive(Debug)]
 struct ReduceState {
@@ -143,12 +143,10 @@ pub struct Reduce {
     max_events: Option<usize>,
 }
 
-fn validate_merge_strategies(
-    strategies: IndexMap<ConfigTargetPath, MergeStrategy>,
-) -> crate::Result<()> {
+fn validate_merge_strategies(strategies: IndexMap<KeyString, MergeStrategy>) -> crate::Result<()> {
     for (path, _) in &strategies {
-        let contains_index = path
-            .0
+        let contains_index = parse_target_path(path)
+            .map_err(|_| format!("Could not parse path: `{path}`"))?
             .path
             .segments
             .iter()
@@ -196,7 +194,13 @@ impl Reduce {
             merge_strategies: config
                 .merge_strategies
                 .iter()
-                .map(|(path, strategy)| (path.0.clone(), strategy.clone()))
+                .filter_map(|(path, strategy)| {
+                    // TODO Invalid paths are ignored to preserve backwards compatibility.
+                    //      Merge strategy paths should ideally be [`lookup_v2::ConfigTargetPath`]
+                    //      which means an invalid path would result in an configuration error.
+                    let parsed_path = parse_target_path(path).ok();
+                    parsed_path.map(|path| (path, strategy.clone()))
+                })
                 .collect(),
             reduce_merge_states: HashMap::new(),
             ends_when,