adding alert_rule fetch function

alerting_alert_rule.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"net/url"
 	"time"
 )
 
@@ -63,6 +64,33 @@ type RelativeTimeRange struct {
 	To   time.Duration `json:"to"`
 }
 
+func (c *Client) AlertRules() ([]AlertRule, error) {
+	const limit = 1000
+
+	var (
+		page          = 0
+		newAlertRules []AlertRule
+		alertRules    []AlertRule
+		query         = make(url.Values)
+	)
+	query.Set("limit", fmt.Sprint(limit))
+
+	for {
+		page++
+		query.Set("page", fmt.Sprint(page))
+
+		if err := c.request("GET", "/api/v1/provisioning/alert-rules", query, nil, &newAlertRules); err != nil {
+			return nil, err
+		}
+
+		alertRules = append(alertRules, newAlertRules...)
+
+		if len(newAlertRules) < limit {
+			return alertRules, nil
+		}
+	}
+}
+
 // AlertRule fetches a single alert rule, identified by its UID.
 func (c *Client) AlertRule(uid string) (AlertRule, error) {
 	path := fmt.Sprintf("/api/v1/provisioning/alert-rules/%s", uid)

alerting_alert_rule_test.go

@@ -2,13 +2,45 @@ package gapi
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/gobs/pretty"
 )
 
 func TestAlertRules(t *testing.T) {
+	mockData := strings.Repeat(getAlertRulesJSON+",", 1000) // make 1000 folders.
+	mockData = "[" + mockData[:len(mockData)-1] + "]"       // remove trailing comma; make a json list.
+
+	// This creates 1000 + 1000 + 1 (2001, 3 calls) worth of folders.
+	client := gapiTestToolsFromCalls(t, []mockServerCall{
+		{200, mockData},
+		{200, mockData},
+		{200, "[" + getFolderJSON + "]"},
+	})
+
+	const dashCount = 2001
+
+	alertRules, err := client.AlertRules()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Log(pretty.PrettyFormat(alertRules))
+
+	if len(alertRules) != dashCount {
+		t.Errorf("Length of returned folders should be %d", dashCount)
+	}
+	if alertRules[0].ID != 1 || alertRules[0].Title != "Departmenet ABC" {
+		t.Error("Not correctly parsing returned folders.")
+	}
+	if alertRules[dashCount-1].ID != 1 || alertRules[dashCount-1].Title != "Departmenet ABC" {
+		t.Error("Not correctly parsing returned folders.")
+	}
+}
+
+func TestAlertRule(t *testing.T) {
 	t.Run("get alert rule succeeds", func(t *testing.T) {
 		client := gapiTestTools(t, 200, getAlertRuleJSON)
 
@@ -161,7 +193,18 @@ const writeAlertRuleJSON = `
 	"for": "1m"
 }
 `
-
+const getAlertRulesJSON = `{
+	"conditions": "A",
+	"data": [{"datasourceUid":"-100","model":{"conditions":[{"evaluator":{"params":[0,0],"type":"gt"},"operator":{"type":"and"},"query":{"params":[]},"reducer":{"params":[],"type":"avg"},"type":"query"}],"datasource":{"type":"__expr__","uid":"__expr__"},"expression":"1 == 1","hide":false,"intervalMs":1000,"maxDataPoints":43200,"refId":"A","type":"math"},"queryType":"","refId":"A","relativeTimeRange":{"from":0,"to":0}}],
+	"execErrState": "OK",
+	"folderUID": "project_test",
+	"noDataState": "OK",
+	"orgId": 1,
+	"uid": "123abcd",
+	"ruleGroup": "eval_group_1",
+	"title": "Always in alarm",
+	"for": "1m"
+}`
 const getAlertRuleJSON = `
 	{
 	"conditions": "A",