func (h *Handler) executeTemplate(w http.ResponseWriter, name string, data interface{}) {
text, err := h.getTemplate(name)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
tmpl := template.NewTemplateExpander(text, name, data, clientmodel.Now(), h.queryEngine, h.options.PathPrefix)
tmpl.Funcs(template_text.FuncMap{
"since": time.Since,
"getConsoles": h.getConsoles,
"pathPrefix": func() string { return h.options.PathPrefix },
"stripLabels": func(lset clientmodel.LabelSet, labels ...clientmodel.LabelName) clientmodel.LabelSet {
for _, ln := range labels {
delete(lset, ln)
}
return lset
},
"globalURL": func(u *url.URL) *url.URL {
for _, lhr := range localhostRepresentations {
if strings.HasPrefix(u.Host, lhr+":") {
u.Host = strings.Replace(u.Host, lhr+":", h.options.Hostname+":", 1)
}
}
return u
},
"healthToClass": func(th retrieval.TargetHealth) string {
switch th {
case retrieval.HealthUnknown:
return "warning"
case retrieval.HealthGood:
return "success"
default:
return "danger"
}
},
"alertStateToClass": func(as rules.AlertState) string {
switch as {
case rules.StateInactive:
return "success"
case rules.StatePending:
return "warning"
case rules.StateFiring:
return "danger"
default:
panic("unknown alert state")
}
},
})
result, err := tmpl.ExpandHTML(nil)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
io.WriteString(w, result)
}
func (m *Manager) queueAlertNotifications(rule *AlertingRule, timestamp clientmodel.Timestamp) {
activeAlerts := rule.ActiveAlerts()
if len(activeAlerts) == 0 {
return
}
notifications := make(notification.NotificationReqs, 0, len(activeAlerts))
for _, aa := range activeAlerts {
if aa.State != StateFiring {
// BUG: In the future, make AlertManager support pending alerts?
continue
}
// Provide the alert information to the template.
l := map[string]string{}
for k, v := range aa.Labels {
l[string(k)] = string(v)
}
tmplData := struct {
Labels map[string]string
Value clientmodel.SampleValue
}{
Labels: l,
Value: aa.Value,
}
// Inject some convenience variables that are easier to remember for users
// who are not used to Go's templating system.
defs := "{{$labels := .Labels}}{{$value := .Value}}"
expand := func(text string) string {
tmpl := template.NewTemplateExpander(defs+text, "__alert_"+rule.Name(), tmplData, timestamp, m.queryEngine, m.externalURL.Path)
result, err := tmpl.Expand()
if err != nil {
result = err.Error()
log.Warnf("Error expanding alert template %v with data '%v': %v", rule.Name(), tmplData, err)
}
return result
}
notifications = append(notifications, ¬ification.NotificationReq{
Summary: expand(rule.summary),
Description: expand(rule.description),
Runbook: rule.runbook,
Labels: aa.Labels.Merge(clientmodel.LabelSet{
alertNameLabel: clientmodel.LabelValue(rule.Name()),
}),
Value: aa.Value,
ActiveSince: aa.ActiveSince.Time(),
RuleString: rule.String(),
GeneratorURL: m.externalURL.String() + strutil.GraphLinkForExpression(rule.vector.String()),
})
}
m.notificationHandler.SubmitReqs(notifications)
}
func (h *Handler) consoles(w http.ResponseWriter, r *http.Request) {
ctx := route.Context(r)
name := route.Param(ctx, "filepath")
file, err := http.Dir(h.options.ConsoleTemplatesPath).Open(name)
if err != nil {
http.Error(w, err.Error(), http.StatusNotFound)
return
}
text, err := ioutil.ReadAll(file)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
// Provide URL parameters as a map for easy use. Advanced users may have need for
// parameters beyond the first, so provide RawParams.
rawParams, err := url.ParseQuery(r.URL.RawQuery)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
params := map[string]string{}
for k, v := range rawParams {
params[k] = v[0]
}
data := struct {
RawParams url.Values
Params map[string]string
Path string
}{
RawParams: rawParams,
Params: params,
Path: strings.TrimLeft(name, "/"),
}
tmpl := template.NewTemplateExpander(string(text), "__console_"+name, data, model.Now(), h.queryEngine, h.options.ExternalURL.Path)
filenames, err := filepath.Glob(h.options.ConsoleLibrariesPath + "/*.lib")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
result, err := tmpl.ExpandHTML(filenames)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
io.WriteString(w, result)
}
func (h *Handler) executeTemplate(w http.ResponseWriter, name string, data interface{}) {
text, err := h.getTemplate(name)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
tmpl := template.NewTemplateExpander(text, name, data, model.Now(), h.queryEngine, h.options.ExternalURL.Path)
tmpl.Funcs(tmplFuncs(h.consolesPath(), h.options))
result, err := tmpl.ExpandHTML(nil)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
io.WriteString(w, result)
}
// eval evaluates the rule expression and then creates pending alerts and fires
// or removes previously pending alerts accordingly.
func (r *AlertingRule) eval(ts model.Time, engine *promql.Engine, externalURLPath string) (model.Vector, error) {
query, err := engine.NewInstantQuery(r.vector.String(), ts)
if err != nil {
return nil, err
}
res, err := query.Exec().Vector()
if err != nil {
return nil, err
}
r.mtx.Lock()
defer r.mtx.Unlock()
// Create pending alerts for any new vector elements in the alert expression
// or update the expression value for existing elements.
resultFPs := map[model.Fingerprint]struct{}{}
for _, smpl := range res {
// Provide the alert information to the template.
l := make(map[string]string, len(smpl.Metric))
for k, v := range smpl.Metric {
l[string(k)] = string(v)
}
tmplData := struct {
Labels map[string]string
Value float64
}{
Labels: l,
Value: float64(smpl.Value),
}
// Inject some convenience variables that are easier to remember for users
// who are not used to Go's templating system.
defs := "{{$labels := .Labels}}{{$value := .Value}}"
expand := func(text model.LabelValue) model.LabelValue {
tmpl := template.NewTemplateExpander(
defs+string(text),
"__alert_"+r.Name(),
tmplData,
ts,
engine,
externalURLPath,
)
result, err := tmpl.Expand()
if err != nil {
result = fmt.Sprintf("<error expanding template: %s>", err)
log.Warnf("Error expanding alert template %v with data '%v': %s", r.Name(), tmplData, err)
}
return model.LabelValue(result)
}
labels := make(model.LabelSet, len(smpl.Metric)+len(r.labels)+1)
for ln, lv := range smpl.Metric {
labels[ln] = lv
}
for ln, lv := range r.labels {
labels[ln] = expand(lv)
}
labels[model.AlertNameLabel] = model.LabelValue(r.Name())
annotations := make(model.LabelSet, len(r.annotations))
for an, av := range r.annotations {
annotations[an] = expand(av)
}
fp := smpl.Metric.Fingerprint()
resultFPs[fp] = struct{}{}
if alert, ok := r.active[fp]; ok && alert.State != StateInactive {
alert.Value = smpl.Value
continue
}
delete(smpl.Metric, model.MetricNameLabel)
r.active[fp] = &Alert{
Labels: labels,
Annotations: annotations,
ActiveAt: ts,
State: StatePending,
Value: smpl.Value,
}
}
var vec model.Vector
// Check if any pending alerts should be removed or fire now. Write out alert timeseries.
for fp, a := range r.active {
if _, ok := resultFPs[fp]; !ok {
if a.State != StateInactive {
vec = append(vec, r.sample(a, ts, false))
}
// If the alert was previously firing, keep it around for a given
// retention time so it is reported as resolved to the AlertManager.
if a.State == StatePending || (a.ResolvedAt != 0 && ts.Sub(a.ResolvedAt) > resolvedRetention) {
delete(r.active, fp)
}
if a.State != StateInactive {
a.State = StateInactive
a.ResolvedAt = ts
}
continue
}
if a.State == StatePending && ts.Sub(a.ActiveAt) >= r.holdDuration {
vec = append(vec, r.sample(a, ts, false))
a.State = StateFiring
}
vec = append(vec, r.sample(a, ts, true))
}
return vec, nil
}
// sendAlerts sends alert notifications for the given rule.
func (g *Group) sendAlerts(rule *AlertingRule, timestamp model.Time) error {
var alerts model.Alerts
for _, alert := range rule.currentAlerts() {
// Only send actually firing alerts.
if alert.State == StatePending {
continue
}
// Provide the alert information to the template.
l := make(map[string]string, len(alert.Labels))
for k, v := range alert.Labels {
l[string(k)] = string(v)
}
tmplData := struct {
Labels map[string]string
Value float64
}{
Labels: l,
Value: float64(alert.Value),
}
// Inject some convenience variables that are easier to remember for users
// who are not used to Go's templating system.
defs := "{{$labels := .Labels}}{{$value := .Value}}"
expand := func(text model.LabelValue) model.LabelValue {
tmpl := template.NewTemplateExpander(
defs+string(text),
"__alert_"+rule.Name(),
tmplData,
timestamp,
g.opts.QueryEngine,
g.opts.ExternalURL.Path,
)
result, err := tmpl.Expand()
if err != nil {
result = fmt.Sprintf("<error expanding template: %s>", err)
log.Warnf("Error expanding alert template %v with data '%v': %s", rule.Name(), tmplData, err)
}
return model.LabelValue(result)
}
labels := make(model.LabelSet, len(alert.Labels)+1)
for ln, lv := range alert.Labels {
labels[ln] = expand(lv)
}
labels[model.AlertNameLabel] = model.LabelValue(rule.Name())
annotations := make(model.LabelSet, len(rule.annotations))
for an, av := range rule.annotations {
annotations[an] = expand(av)
}
a := &model.Alert{
StartsAt: alert.ActiveAt.Add(rule.holdDuration).Time(),
Labels: labels,
Annotations: annotations,
GeneratorURL: g.opts.ExternalURL.String() + strutil.GraphLinkForExpression(rule.vector.String()),
}
if alert.ResolvedAt != 0 {
a.EndsAt = alert.ResolvedAt.Time()
}
alerts = append(alerts, a)
}
if len(alerts) > 0 {
g.opts.NotificationHandler.Send(alerts...)
}
return nil
}