--- a/pkg/common/attributes.go	Fri Jan 25 11:26:20 2019 +0100
+++ b/pkg/common/attributes.go	Fri Jan 25 11:52:54 2019 +0100
@@ -20,9 +20,31 @@
 	"time"
 )
 
-// Attributes is a map of optional key/value attributes
-// of a configuration.
-type Attributes map[string]string
+type (
+
+	// Attributes is a map of optional key/value attributes
+	// of a configuration.
+	Attributes map[string]string
+
+	AttributesMarshaler interface {
+		MarshalAttributes(Attributes) error
+	}
+
+	AttributesUnmarshaler interface {
+		UnmarshalAttributes(Attributes) error
+	}
+)
+
+func (ca Attributes) Delete(key string) bool {
+	if ca == nil {
+		return false
+	}
+	if _, found := ca[key]; !found {
+		return false
+	}
+	delete(ca, key)
+	return true
+}
 
 // Get fetches a value for given key out of the configuration.
 // If the key was not found the bool component of the return value
@@ -35,19 +57,39 @@
 	return value, found
 }
 
+func (ca Attributes) Set(key, value string) bool {
+	if ca == nil {
+		return false
+	}
+	ca[key] = value
+	return true
+}
+
 // Bool returns a bool value for a given key.
 func (ca Attributes) Bool(key string) bool {
 	s, found := ca.Get(key)
 	return found && strings.ToLower(s) == "true"
 }
 
+func (ca Attributes) SetBool(key string, value bool) bool {
+	var v string
+	if value {
+		v = "true"
+	} else {
+		v = "false"
+	}
+	return ca.Set(key, v)
+}
+
+const TimeFormat = "2006-01-02T15:04:05"
+
 // Time gives a time.Time for a given key.
 func (ca Attributes) Time(key string) (time.Time, bool) {
 	s, found := ca.Get(key)
 	if !found {
 		return time.Time{}, false
 	}
-	t, err := time.Parse("2006-01-02T15:04:05", s)
+	t, err := time.Parse(TimeFormat, s)
 	if err != nil {
 		log.Printf("error: %v\n", err)
 		return time.Time{}, false
@@ -55,6 +97,12 @@
 	return t, true
 }
 
+func (ca Attributes) SetTime(key string, t time.Time) bool {
+	value := t.Format(TimeFormat)
+	return ca.Set(key, value)
+
+}
+
 func (ca Attributes) Int(key string) (int, bool) {
 	s, found := ca.Get(key)
 	if !found {
@@ -68,6 +116,11 @@
 	return i, true
 }
 
+func (ca Attributes) SetInt(key string, value int) bool {
+	v := strconv.Itoa(value)
+	return ca.Set(key, v)
+}
+
 func (ca Attributes) Duration(key string) (time.Duration, bool) {
 	s, found := ca.Get(key)
 	if !found {
@@ -80,3 +133,8 @@
 	}
 	return d, true
 }
+
+func (ca Attributes) SetDuration(key string, value time.Duration) bool {
+	v := value.String()
+	return ca.Set(key, v)
+}