Rework output disposition configuration

rfcs/2022-08-25-12217-handling-discarded-events.md

@@ -94,30 +94,41 @@ outputs.errors.disposition = "reject"
 
 #### Configuration
 
-The new options will show up in all of the enclosing configuration option structures:
+The new `output.*.disposition` configuration mapping will be added to components as needed to
+support configuring outputs. In order for the validation to access it, a new method will be added to
+all component configuration traits:
 
 ```rust
-struct SourceOuter {
-    …
+trait SourceConfig: NamedComponent + Debug + Send + Sync {
+    /// Gets the list of outputs exposed by this source (existing).
+    fn outputs(&self, global_log_namespace: LogNamespace) -> Vec<config::Output>;
 
-    /// The configuration of all named outputs.
-    outputs: HashMap<String, OutputConfig>,
+    /// The actual user configuration of outputs.
+    /// Will be `None` if no such configuration is present on this component.
+    fn outputs_config(&self) -> Option<&OutputsConfig>;
 }
 
-struct TransformOuter {
-    …
+trait TransformConfig: DescribeOutputs + NamedComponent + Debug + Send + Sync {
+    /// Gets the list of outputs exposed by this transform (existing).
+    fn outputs(&self, merged_definition: &schema::Definition) -> Vec<config::Output>;
 
-    /// The configuration of all named outputs.
-    outputs: HashMap<String, OutputConfig>,
+    /// The actual user configuration of outputs.
+    /// Will be `None` if no such configuration is present on this component.
+    fn outputs_config(&self) -> Option<&OutputsConfig>;
 }
 
-struct SinkOuter {
-    …
+trait SinkConfig: DescribeOutputs + NamedComponent + Debug + Send + Sync {
+    /// Gets the list of outputs exposed by this sink.
+    fn outputs(&self) -> Vec<config::Output>;
 
-    /// The configuration of all named outputs.
-    outputs: HashMap<String, OutputConfig>,
+    /// The actual user configuration of outputs.
+    /// Will be `None` if no such configuration is present on this component.
+    fn outputs_config(&self) -> Option<&OutputsConfig>;
 }
 
+/// Configuration for a set of named outputs.
+struct OutputsConfig(HashMap<String, OutputConfig>);
+
 struct OutputConfig {
     #[serde(default)]
     disposition: OutputDisposition,
@@ -348,6 +359,9 @@ in isolation.
   only when the output isn't consumed by another component? Do we need another disposition marker to
   indicate discards are not to be counted as errors?
 
+- Does the list of outputs exposed by the sink need the schema definition passed in like transforms
+  do?
+
 ## Plan Of Attack
 
 Incremental steps to execute this change. These will be converted to issues after the RFC is approved: