Implement attachment checking in CLI (#141)

pkg/customization/customize.go

@@ -0,0 +1,79 @@
+// Package customization contains the structure for the customization
+// file to configure the OTS web- and command-line interface
+package customization
+
+import (
+	"encoding/json"
+	"io/fs"
+	"os"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"gopkg.in/yaml.v2"
+)
+
+type (
+	// Customize holds the structure of the customization file
+	Customize struct {
+		AppIcon              string `json:"appIcon,omitempty" yaml:"appIcon"`
+		AppTitle             string `json:"appTitle,omitempty" yaml:"appTitle"`
+		DisableAppTitle      bool   `json:"disableAppTitle,omitempty" yaml:"disableAppTitle"`
+		DisablePoweredBy     bool   `json:"disablePoweredBy,omitempty" yaml:"disablePoweredBy"`
+		DisableQRSupport     bool   `json:"disableQRSupport,omitempty" yaml:"disableQRSupport"`
+		DisableThemeSwitcher bool   `json:"disableThemeSwitcher,omitempty" yaml:"disableThemeSwitcher"`
+
+		DisableExpiryOverride bool    `json:"disableExpiryOverride,omitempty" yaml:"disableExpiryOverride"`
+		ExpiryChoices         []int64 `json:"expiryChoices,omitempty" yaml:"expiryChoices"`
+
+		AcceptedFileTypes      string `json:"acceptedFileTypes" yaml:"acceptedFileTypes"`
+		DisableFileAttachment  bool   `json:"disableFileAttachment" yaml:"disableFileAttachment"`
+		MaxAttachmentSizeTotal int64  `json:"maxAttachmentSizeTotal" yaml:"maxAttachmentSizeTotal"`
+
+		OverlayFSPath     string `json:"-" yaml:"overlayFSPath"`
+		UseFormalLanguage bool   `json:"-" yaml:"useFormalLanguage"`
+	}
+)
+
+// Load retrieves the Customization file from filesystem
+func Load(filename string) (cust Customize, err error) {
+	if filename == "" {
+		// None given, take a shortcut
+		cust.applyFixes()
+		return cust, nil
+	}
+
+	cf, err := os.Open(filename) //#nosec:G304 // Loading a custom file is the intention here
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			logrus.Warn("customize file given but not found")
+			return cust, nil
+		}
+		return cust, errors.Wrap(err, "opening customize file")
+	}
+	defer func() {
+		if err := cf.Close(); err != nil {
+			logrus.WithError(err).Error("closing customize file (leaked fd)")
+		}
+	}()
+
+	if err = yaml.NewDecoder(cf).Decode(&cust); err != nil {
+		return cust, errors.Wrap(err, "decoding customize file")
+	}
+
+	cust.applyFixes()
+
+	return cust, nil
+}
+
+// ToJSON is a templating helper which returns the customization
+// serialized as JSON in a string
+func (c Customize) ToJSON() (string, error) {
+	j, err := json.Marshal(c)
+	return string(j), errors.Wrap(err, "marshalling JSON")
+}
+
+func (c *Customize) applyFixes() {
+	if len(c.AppTitle) == 0 {
+		c.AppTitle = "OTS - One Time Secrets"
+	}
+}