builder: start the collector with the parsing of featuregates

Signed-off-by: Benedikt Bongartz <bongartz@klimlive.de>

.chloggen/fix_featuregate_late_initialization.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: builder
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix featuregate late initialization
+
+# One or more tracking issues or pull requests related to the change
+issues: [4967]
+
+# (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/builder/internal/builder/templates/main.go.tmpl

@@ -5,11 +5,16 @@ package main
 
 import (
 	"log"
+
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/otelcol"
 )
 
 func main() {
+	if err := otelcol.NewCommandFeatureGate().Execute(); err != nil {
+		log.Fatalf("failed to validate featuregates: %v", err)
+	}
+
 	factories, err := components()
 	if err != nil {
 		log.Fatalf("failed to build components: %v", err)

otelcol/command.go

@@ -12,6 +12,14 @@ import (
 	"go.opentelemetry.io/collector/featuregate"
 )
 
+// NewCommandFeatureGate constructs a new cobra.Command used to parse given FeatureGates.
+func NewCommandFeatureGate() *cobra.Command {
+	flagSet := flags(featuregate.GlobalRegistry())
+	rootCmd := &cobra.Command{SilenceUsage: true}
+	rootCmd.Flags().AddGoFlagSet(flagSet)
+	return rootCmd
+}
+
 // NewCommand constructs a new cobra.Command using the given CollectorSettings.
 func NewCommand(set CollectorSettings) *cobra.Command {
 	flagSet := flags(featuregate.GlobalRegistry())