Definition of policy tree and matcher serialization logic

Author: alexweav

alerting_notification_policy.go

@@ -0,0 +1,113 @@
+package gapi
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"time"
+)
+
+// Represents a notification routing tree in Grafana Alerting.
+type NotificationPolicy struct {
+	Receiver       string           `json:"receiver,omitempty"`
+	GroupBy        []string         `json:"group_by,omitempty"`
+	Routes         []SpecificPolicy `json:"routes,omitempty"`
+	GroupWait      time.Duration    `json:"group_wait,omitempty"`
+	GroupInterval  time.Duration    `json:"group_interval,omitempty"`
+	RepeatInterval time.Duration    `json:"repeat_interval,omitempty"`
+	Provenance     string           `json:"provenance,omitempty"`
+}
+
+// Represents a non-root node in a notification routing tree.
+type SpecificPolicy struct {
+	Receiver          string           `json:"receiver,omitempty"`
+	GroupBy           []string         `json:"group_by,omitempty"`
+	ObjectMatchers    Matchers         `json:"object_matchers,omitempty"`
+	MuteTimeIntervals []string         `json:"mute_time_intervals,omitempty"`
+	Continue          bool             `json:"continue"`
+	Routes            []SpecificPolicy `json:"routes,omitempty"`
+	GroupWait         time.Duration    `json:"group_wait,omitempty"`
+	GroupInterval     time.Duration    `json:"group_interval,omitempty"`
+	RepeatInterval    time.Duration    `json:"repeat_interval,omitempty"`
+}
+
+type Matchers []Matcher
+
+type Matcher struct {
+	Type  MatchType
+	Name  string
+	Value string
+	re    *regexp.Regexp
+}
+
+type MatchType int
+
+const (
+	MatchEqual MatchType = iota
+	MatchNotEqual
+	MatchRegexp
+	MatchNotRegexp
+)
+
+func (m MatchType) String() string {
+	typeToStr := map[MatchType]string{
+		MatchEqual:     "=",
+		MatchNotEqual:  "!=",
+		MatchRegexp:    "=~",
+		MatchNotRegexp: "!~",
+	}
+	if str, ok := typeToStr[m]; ok {
+		return str
+	}
+	panic("unknown match type")
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface for Matchers.
+func (m *Matchers) UnmarshalJSON(data []byte) error {
+	var rawMatchers [][3]string
+	if err := json.Unmarshal(data, &rawMatchers); err != nil {
+		return err
+	}
+	for _, rawMatcher := range rawMatchers {
+		var matchType MatchType
+		switch rawMatcher[1] {
+		case "=":
+			matchType = MatchEqual
+		case "!=":
+			matchType = MatchNotEqual
+		case "=~":
+			matchType = MatchRegexp
+		case "!~":
+			matchType = MatchNotRegexp
+		default:
+			return fmt.Errorf("unsupported match type %q in matcher", rawMatcher[1])
+		}
+
+		matcher := Matcher{
+			Type:  matchType,
+			Name:  rawMatcher[0],
+			Value: rawMatcher[2],
+		}
+		if matchType == MatchRegexp || matchType == MatchNotRegexp {
+			re, err := regexp.Compile("^(?:" + rawMatcher[2] + ")$")
+			if err != nil {
+				return err
+			}
+			matcher.re = re
+		}
+		*m = append(*m, matcher)
+	}
+	return nil
+}
+
+// MarshalJSON implements the json.Marshaler interface for Matchers.
+func (m Matchers) MarshalJSON() ([]byte, error) {
+	if len(m) == 0 {
+		return nil, nil
+	}
+	result := make([][3]string, len(m))
+	for i, matcher := range m {
+		result[i] = [3]string{matcher.Name, matcher.Type.String(), matcher.Value}
+	}
+	return json.Marshal(result)
+}