fixes: panic in case of zap logger init on windows os

.goreleaser.yml

@@ -24,6 +24,10 @@ archives:
       windows: Windows
       386: i386
       amd64: x86_64
+    # for windows it is good to have zip rather than tar.gz
+    format_overrides:
+      - goos: windows
+        format: zip
 checksum:
   name_template: 'checksums.txt'
 snapshot:

pkg/logging/logger.go

@@ -17,13 +17,21 @@
 package logging
 
 import (
+	"fmt"
+	"net/url"
+	"os"
 	"path/filepath"
 
+	"github.com/tenable/terrascan/pkg/utils"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
 
-const logFileName = "terrascan.log"
+const (
+	logFileName                   = "terrascan.log"
+	terrascanZapSink              = "terrascan-winfile-sink"
+	terrascanZapSinkWithSeparator = terrascanZapSink + ":///"
+)
 
 var globalLogger *zap.SugaredLogger
 
@@ -86,10 +94,16 @@ func GetLogger(logLevel, encoding, logDir string, encodingLevel func(zapcore.Lev
 	}
 
 	if logDir != "" {
-		zapConfig.OutputPaths = append(zapConfig.OutputPaths, filepath.Join(logDir, logFileName))
+		logDirPath := filepath.Join(logDir, logFileName)
+		// currently zap's default file sink do not support handling of windows files
+		// so if we are on windows os register an sink which will handle the opening of file.
+		if utils.IsWindowsPlatform() {
+			zap.RegisterSink(terrascanZapSink, newTerrascanWinFileSink)
+			logDirPath = terrascanZapSinkWithSeparator + logDirPath
+		}
+		zapConfig.OutputPaths = append(zapConfig.OutputPaths, logDirPath)
 	}
-
-	// create zap logger
+	// should we panic here?
 	logger, _ := zapConfig.Build()
 
 	return logger
@@ -99,3 +113,29 @@ func GetLogger(logLevel, encoding, logDir string, encodingLevel func(zapcore.Lev
 func GetDefaultLogger() *zap.SugaredLogger {
 	return globalLogger
 }
+
+// newTerrascanWinFileSink custome sink to open file on windows
+// https://github.com/uber-go/zap/issues/621#issue-350197709 - referred from this issue comment
+func newTerrascanWinFileSink(u *url.URL) (zap.Sink, error) {
+	// copy pasting this error from default FileSink of zap to keep the standard behaviour across all platforms
+	// newFileSink()
+	if u.User != nil {
+		return nil, fmt.Errorf("user and password not allowed with file URLs: got %v", u)
+	}
+	if u.Fragment != "" {
+		return nil, fmt.Errorf("fragments not allowed with file URLs: got %v", u)
+	}
+	if u.RawQuery != "" {
+		return nil, fmt.Errorf("query parameters not allowed with file URLs: got %v", u)
+	}
+	// Error messages are better if we check hostname and port separately.
+	if u.Port() != "" {
+		return nil, fmt.Errorf("ports not allowed with file URLs: got %v", u)
+	}
+	if hn := u.Hostname(); hn != "" && hn != "localhost" {
+		return nil, fmt.Errorf("file URLs must leave host empty or use localhost: got %v", u)
+	}
+	// after url.Parse() u.Path contains and extra leading slash
+	// Remove leading slash left by url.Parse()
+	return os.OpenFile(u.Path[1:], os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0666)
+}