logging: Add subsystem to log API (#19002)

Create new code paths for multiple subsystems in the code. This will
make maintaing this easier later.

Also introduce bugLogIf() for errors that should not happen in the first
place.

cmd/auth-handler.go

@@ -126,7 +126,7 @@ func getRequestAuthType(r *http.Request) (at authType) {
 		var err error
 		r.Form, err = url.ParseQuery(r.URL.RawQuery)
 		if err != nil {
-			logger.LogIf(r.Context(), err)
+			authNLogIf(r.Context(), err)
 			return authTypeUnknown
 		}
 	}
@@ -257,7 +257,7 @@ func getClaimsFromTokenWithSecret(token, secret string) (map[string]interface{},
 		if err != nil {
 			// Base64 decoding fails, we should log to indicate
 			// something is malforming the request sent by client.
-			logger.LogIf(GlobalContext, err, logger.ErrorKind)
+			authNLogIf(GlobalContext, err, logger.ErrorKind)
 			return nil, errAuthentication
 		}
 		claims.MapClaims[sessionPolicyNameExtracted] = string(spBytes)
@@ -353,7 +353,7 @@ func checkRequestAuthTypeWithVID(ctx context.Context, r *http.Request, action po
 
 func authenticateRequest(ctx context.Context, r *http.Request, action policy.Action) (s3Err APIErrorCode) {
 	if logger.GetReqInfo(ctx) == nil {
-		logger.LogIf(ctx, errors.New("unexpected context.Context does not have a logger.ReqInfo"), logger.ErrorKind)
+		bugLogIf(ctx, errors.New("unexpected context.Context does not have a logger.ReqInfo"), logger.ErrorKind)
 		return ErrAccessDenied
 	}
 
@@ -392,7 +392,7 @@ func authenticateRequest(ctx context.Context, r *http.Request, action policy.Act
 		// To extract region from XML in request body, get copy of request body.
 		payload, err := io.ReadAll(io.LimitReader(r.Body, maxLocationConstraintSize))
 		if err != nil {
-			logger.LogIf(ctx, err, logger.ErrorKind)
+			authZLogIf(ctx, err, logger.ErrorKind)
 			return ErrMalformedXML
 		}