enables multi-tag build and publish

types.go

@@ -0,0 +1,45 @@
+package main
+
+import "encoding/json"
+
+// StrSlice representes a string or an array of strings.
+// We need to override the json decoder to accept both options.
+type StrSlice struct {
+	parts []string
+}
+
+// UnmarshalJSON decodes the byte slice whether it's a string or an array of strings.
+// This method is needed to implement json.Unmarshaler.
+func (e *StrSlice) UnmarshalJSON(b []byte) error {
+	if len(b) == 0 {
+		return nil
+	}
+
+	p := make([]string, 0, 1)
+	if err := json.Unmarshal(b, &p); err != nil {
+		var s string
+		if err := json.Unmarshal(b, &s); err != nil {
+			return err
+		}
+		p = append(p, s)
+	}
+
+	e.parts = p
+	return nil
+}
+
+// Len returns the number of parts of the StrSlice.
+func (e *StrSlice) Len() int {
+	if e == nil {
+		return 0
+	}
+	return len(e.parts)
+}
+
+// Slice gets the parts of the StrSlice as a Slice of string.
+func (e *StrSlice) Slice() []string {
+	if e == nil {
+		return nil
+	}
+	return e.parts
+}