Fix validate command (#9866)

**Description:**
Fixes issue where validate command was not properly printing valid
values.

**Link to tracking Issue:**
Closes
#9863

**Testing:**
Updated unit tests

Author: TylerHelmuth

.chloggen/fix-validate-command.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: otelcol
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix issue where the `validate` command wasn't properly printing valid component type.
+
+# One or more tracking issues or pull requests related to the change
+issues: [9866]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

cmd/otelcorecol/go.mod

@@ -43,7 +43,7 @@ require (
 	github.com/go-viper/mapstructure/v2 v2.0.0-alpha.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
-	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
@@ -121,11 +121,12 @@ require (
 	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.27.0 // indirect
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa // indirect
 	golang.org/x/net v0.22.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	gonum.org/v1/gonum v0.15.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20240221002015-b0ce06bbee7c // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240221002015-b0ce06bbee7c // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240314234333-6e1732d8331c // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240314234333-6e1732d8331c // indirect
 	google.golang.org/grpc v1.62.1 // indirect
 	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

cmd/otelcorecol/go.sum

@@ -24,6 +24,7 @@ require (
 	go.uber.org/goleak v1.3.0
 	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.27.0
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa
 	golang.org/x/sys v0.18.0
 	google.golang.org/grpc v1.62.1
 	gopkg.in/yaml.v3 v3.0.1

otelcol/go.mod

@@ -5,7 +5,8 @@ package configunmarshaler // import "go.opentelemetry.io/collector/otelcol/inter
 
 import (
 	"fmt"
-	"reflect"
+
+	"golang.org/x/exp/maps"
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/confmap"
@@ -34,7 +35,7 @@ func (c *Configs[F]) Unmarshal(conf *confmap.Conf) error {
 		// Find factory based on component kind and type that we read from config source.
 		factory, ok := c.factories[id.Type()]
 		if !ok {
-			return errorUnknownType(id, reflect.ValueOf(c.factories).MapKeys())
+			return errorUnknownType(id, maps.Keys(c.factories))
 		}
 
 		// Create the default config for this component.
@@ -56,7 +57,7 @@ func (c *Configs[F]) Configs() map[component.ID]component.Config {
 	return c.cfgs
 }
 
-func errorUnknownType(id component.ID, factories []reflect.Value) error {
+func errorUnknownType(id component.ID, factories []component.Type) error {
 	return fmt.Errorf("unknown type: %q for id: %q (valid values: %v)", id.Type(), id, factories)
 }
 

otelcol/internal/configunmarshaler/configs.go

@@ -104,7 +104,7 @@ func TestUnmarshalError(t *testing.T) {
 					conf: confmap.NewFromStringMap(map[string]any{
 						"nosuch" + tk.kind: nil,
 					}),
-					expectedError: "unknown type: \"nosuch" + tk.kind + "\"",
+					expectedError: "unknown type: \"nosuch" + tk.kind + "\" for id: \"nosuch" + tk.kind + "\" (valid values: [nop])",
 				},
 				{
 					name: "duplicate",