better packaging

- update readme

monitor.go

@@ -0,0 +1,133 @@
+package cachet
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"net/http"
+	"strconv"
+	"time"
+)
+
+const timeout = time.Duration(time.Second)
+
+// Monitor data model
+type Monitor struct {
+	Name               string  `json:"name"`
+	URL                string  `json:"url"`
+	MetricID           int     `json:"metric_id"`
+	Threshold          float32 `json:"threshold"`
+	ComponentID        *int    `json:"component_id"`
+	ExpectedStatusCode int     `json:"expected_status_code"`
+	StrictTLS          *bool   `json:"strict_tls"`
+
+	History        []bool    `json:"-"`
+	LastFailReason *string   `json:"-"`
+	Incident       *Incident `json:"-"`
+}
+
+// Run loop
+func (monitor *Monitor) Run() {
+	reqStart := getMs()
+	isUp := monitor.doRequest()
+	lag := getMs() - reqStart
+
+	if len(monitor.History) >= 10 {
+		monitor.History = monitor.History[len(monitor.History)-9:]
+	}
+	monitor.History = append(monitor.History, isUp)
+	monitor.AnalyseData()
+
+	if isUp == true && monitor.MetricID > 0 {
+		SendMetric(monitor.MetricID, lag)
+	}
+}
+
+func (monitor *Monitor) doRequest() bool {
+	client := &http.Client{
+		Timeout: timeout,
+	}
+	if monitor.StrictTLS != nil && *monitor.StrictTLS == false {
+		client.Transport = &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+		}
+	}
+
+	resp, err := client.Get(monitor.URL)
+	if err != nil {
+		errString := err.Error()
+		monitor.LastFailReason = &errString
+		return false
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode != monitor.ExpectedStatusCode {
+		failReason := "Unexpected response code: " + strconv.Itoa(resp.StatusCode) + ". Expected " + strconv.Itoa(monitor.ExpectedStatusCode)
+		monitor.LastFailReason = &failReason
+		return false
+	}
+
+	return true
+}
+
+// AnalyseData decides if the monitor is statistically up or down and creates / resolves an incident
+func (monitor *Monitor) AnalyseData() {
+	// look at the past few incidents
+	numDown := 0
+	for _, wasUp := range monitor.History {
+		if wasUp == false {
+			numDown++
+		}
+	}
+
+	t := (float32(numDown) / float32(len(monitor.History))) * 100
+	Logger.Printf("%s %.2f%% Down at %v. Threshold: %.2f%%\n", monitor.URL, t, time.Now().UnixNano()/int64(time.Second), monitor.Threshold)
+
+	if len(monitor.History) != 10 {
+		// not enough data
+		return
+	}
+
+	if t > monitor.Threshold && monitor.Incident == nil {
+		// is down, create an incident
+		Logger.Println("Creating incident...")
+
+		component_id := json.Number(strconv.Itoa(*monitor.ComponentID))
+		monitor.Incident = &Incident{
+			Name:        monitor.Name + " - " + Config.SystemName,
+			Message:     monitor.Name + " check failed",
+			ComponentID: &component_id,
+		}
+
+		if monitor.LastFailReason != nil {
+			monitor.Incident.Message += "\n\n - " + *monitor.LastFailReason
+		}
+
+		// set investigating status
+		monitor.Incident.SetInvestigating()
+
+		// create/update incident
+		monitor.Incident.Send()
+		monitor.Incident.UpdateComponent()
+	} else if t < monitor.Threshold && monitor.Incident != nil {
+		// was down, created an incident, its now ok, make it resolved.
+		Logger.Println("Updating incident to resolved...")
+
+		component_id := json.Number(strconv.Itoa(*monitor.ComponentID))
+		monitor.Incident = &Incident{
+			Name:        monitor.Incident.Name,
+			Message:     monitor.Name + " check succeeded",
+			ComponentID: &component_id,
+		}
+
+		monitor.Incident.SetFixed()
+		monitor.Incident.Send()
+		monitor.Incident.UpdateComponent()
+
+		monitor.Incident = nil
+	}
+}
+
+func getMs() int64 {
+	return time.Now().UnixNano() / int64(time.Millisecond)
+}