Add focused configuration reports

integrations/ckconfig/show.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"strings"
 
 	commandkit "go.maximumdirect.net/commandkit"
 )
@@ -31,6 +32,31 @@ func runConfigShow[I, S any](invocation commandkit.Invocation, plan *configOpera
 		if err := invocation.Context.Err(); err != nil {
 			return configFailure("Configuration show was canceled.", acquired.Explanation, err)
 		}
+		if plan.pathSet {
+			if acquired.Value.Explanation == nil {
+				return configFailure("Configuration scope did not provide explanation data.", acquired.Explanation, fmt.Errorf("configuration scope %q declared path show without an explanation reader", selected.scope.scope.Name))
+			}
+			explanation, found := acquired.Value.Explanation.Explain(plan.path)
+			if !found || !explanation.Effective.Present {
+				return configFailure("The requested effective configuration path is not available.", acquired.Explanation, fmt.Errorf("configuration path %q is not effective in scope %q", plan.path.String(), selected.scope.scope.Name))
+			}
+			if err := invocation.Context.Err(); err != nil {
+				return configFailure("Configuration show was canceled.", acquired.Explanation, err)
+			}
+			var value any
+			err := reporter.RenderOutput(func(io.Writer) error {
+				var err error
+				value, err = commandkit.DecodeYAMLReport(strings.NewReader(explanation.Effective.YAML))
+				return err
+			})
+			if err == nil {
+				if canceled := invocation.Context.Err(); canceled != nil {
+					return configFailure("Configuration show was canceled.", acquired.Explanation, canceled)
+				}
+				_ = reporter.Report(commandkit.Report{Value: value})
+			}
+			return commandkit.Success()
+		}
 		if acquired.Value.Effective == nil {
 			return commandkit.Failure(fmt.Sprintf("Configuration scope %q did not provide an effective configuration writer.", selected.scope.scope.Name))
 		}