feat: use viper and cobra to parameterize creation values with viper yaml

internal/io/writer.go

@@ -0,0 +1,33 @@
+package io
+
+import (
+	"fmt"
+	"os"
+
+	"gitlab.com/urkob/go-cert-gen/pkg/io"
+)
+
+type writer struct {
+	dirPath string
+}
+
+func (w writer) WriteFile(filename string, data []byte) (string, error) {
+	if w.dirPath == "" {
+		return "", fmt.Errorf("export directory cannot be empty")
+	}
+
+	if err := os.MkdirAll(w.dirPath, 0o755); err != nil {
+		return "", err
+	}
+	outputPath := w.dirPath + "/" + filename
+	if err := os.WriteFile(outputPath, data, 0o600); err != nil {
+		return "", err
+	}
+	return outputPath, nil
+}
+
+func NewWriter(dirPath string) io.WriterIface {
+	return &writer{
+		dirPath: dirPath,
+	}
+}