[log] Add debug logging to difc/sink_server_ids (#2034)

lpcox · web-flow · commit a774683bf170 · 2026-03-16T10:42:05.000-07:00
## Summary Adds a debug logger (`logSink`) to `internal/difc/sink_server_ids.go` using the project's standard `logger.New("difc:sink_server_ids")` pattern. This file configures which backend server IDs receive DIFC tag snapshot enrichment in RPC JSONL logs, and previously had no debug visibility. ## Changes **File modified:** `internal/difc/sink_server_ids.go` - Added `logger` import and `var logSink = logger.New("difc:sink_server_ids")` declaration - **`SetSinkServerIDs`**: logs input count on entry, logs when config is cleared, logs skipped duplicate IDs, logs final normalized IDs and count after sorting - **`IsSinkServerID`**: logs when a match is found (called frequently, so only logs on positive match to minimize noise) ## Logging calls added (5 total) | Location | Message | Purpose | |---|---|---| | `SetSinkServerIDs` entry | `Setting sink server IDs: input_count=N` | Trace configuration calls | | `SetSinkServerIDs` empty case | `No sink server IDs provided, clearing configuration` | Visible config reset | | `SetSinkServerIDs` loop | `Skipping duplicate sink server ID: %s` | Debug dedup logic | | `SetSinkServerIDs` end | `Sink server IDs configured: count=N, ids=[...]` | Final state confirmation | | `IsSinkServerID` match | `Sink server ID match: serverID=%s` | Trace positive lookups | ## Logger naming convention Follows `pkg:filename` convention: `"difc:sink_server_ids"` for `internal/difc/sink_server_ids.go`. ## Testing Enable with `DEBUG=difc:* ./awmg --config config.toml` to see all difc debug logs including the new sink server ID logs. > Generated by [Go Logger Enhancement](https://github.com/github/gh-aw-mcpg/actions/runs/23152584774) · [◷](https://github.com/search?q=repo%3Agithub%2Fgh-aw-mcpg+%22gh-aw-workflow-id%3A+go-logger%22&type=pullrequests)
diff --git a/internal/difc/sink_server_ids.go b/internal/difc/sink_server_ids.go
@@ -4,8 +4,12 @@ import (
 	"sort"
 	"strings"
 	"sync"
+
+	"github.com/github/gh-aw-mcpg/internal/logger"
 )
 
+var logSink = logger.New("difc:sink_server_ids")
+
 var (
 	sinkServerIDsMu sync.RWMutex
 	sinkServerIDs   = []string{}
@@ -14,11 +18,20 @@ var (
 // SetSinkServerIDs configures backend server IDs that should receive DIFC tag snapshot
 // enrichment in RPC JSONL logs.
 func SetSinkServerIDs(serverIDs []string) {
+	logSink.Printf("Setting sink server IDs: input_count=%d", len(serverIDs))
+
+	var (
+		normalizedOut []string
+		duplicateIDs  []string
+	)
+
 	sinkServerIDsMu.Lock()
-	defer sinkServerIDsMu.Unlock()
 
 	if len(serverIDs) == 0 {
 		sinkServerIDs = nil
+		sinkServerIDsMu.Unlock()
+
+		logSink.Print("No sink server IDs provided, clearing configuration")
 		return
 	}
 
@@ -30,6 +43,7 @@ func SetSinkServerIDs(serverIDs []string) {
 			continue
 		}
 		if _, exists := unique[trimmed]; exists {
+			duplicateIDs = append(duplicateIDs, trimmed)
 			continue
 		}
 		unique[trimmed] = struct{}{}
@@ -38,17 +52,32 @@ func SetSinkServerIDs(serverIDs []string) {
 
 	sort.Strings(normalized)
 	sinkServerIDs = normalized
+	normalizedOut = normalized
+
+	sinkServerIDsMu.Unlock()
+
+	for _, id := range duplicateIDs {
+		logSink.Printf("Skipping duplicate sink server ID: %s", id)
+	}
+
+	logSink.Printf("Sink server IDs configured: count=%d, ids=%v", len(normalizedOut), normalizedOut)
 }
 
 // IsSinkServerID reports whether serverID is in the configured set of DIFC sink server IDs.
 func IsSinkServerID(serverID string) bool {
 	sinkServerIDsMu.RLock()
-	defer sinkServerIDsMu.RUnlock()
-
+	matched := false
 	for _, sinkServerID := range sinkServerIDs {
 		if serverID == sinkServerID {
-			return true
+			matched = true
+			break
 		}
 	}
+	sinkServerIDsMu.RUnlock()
+
+	if matched {
+		logSink.Printf("Sink server ID match: serverID=%s", serverID)
+		return true
+	}
 	return false
 }
