From 755779adb77ecd5650b3d7813cde97e824ad8c0a Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Thu, 13 Jan 2022 23:30:38 +0200
Subject: [PATCH] app/vmalert: add `parseDuration` function in the same way as
 Prometheus does

See https://github.com/prometheus/prometheus/pull/8817
---
 app/vmalert/notifier/template_func.go | 10 ++++++++++
 docs/CHANGELOG.md                     |  1 +
 2 files changed, 11 insertions(+)

diff --git a/app/vmalert/notifier/template_func.go b/app/vmalert/notifier/template_func.go
index 2732895b7..4a42c07e7 100644
--- a/app/vmalert/notifier/template_func.go
+++ b/app/vmalert/notifier/template_func.go
@@ -27,6 +27,7 @@ import (
 	textTpl "text/template"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/datasource"
+	"github.com/VictoriaMetrics/metricsql"
 )
 
 // metric is private copy of datasource.Metric,
@@ -102,6 +103,15 @@ func InitTemplateFunc(externalURL *url.URL) {
 			return host
 		},
 
+		// parseDuration parses a duration string such as "1h" into the number of seconds it represents
+		"parseDuration": func(d string) (float64, error) {
+			ms, err := metricsql.DurationValue(d, 0)
+			if err != nil {
+				return 0, err
+			}
+			return float64(ms) / 1000, nil
+		},
+
 		/* Numbers */
 
 		// humanize converts given number to a human readable format
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index da6ab4837..e1269af46 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -24,6 +24,7 @@ scrape_configs:
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): print the last sample timestamp when the data migration is interrupted either by user or by error. This helps continuing the data migration from the interruption moment. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1236).
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): expose `vmalert_remotewrite_total` metric at `/metrics` page. This makes possible calculating SLOs for error rate during writing recording rules and alert state to `-remoteWrite.url` with the query `vmalert_remotewrite_errors_total / vmalert_remotewrite_total`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2040). Thanks to @afoninsky .
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): add `stripPort` template function in the same way as [Prometheus does](https://github.com/prometheus/prometheus/pull/10002).
+* FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): add `parseDuration` template function in the same way as [Prometheus does](https://github.com/prometheus/prometheus/pull/8817).
 
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): make sure that `vmagent` replicas scrape the same targets at different time offsets when [replication is enabled in vmagent clustering mode](https://docs.victoriametrics.com/vmagent.html#scraping-big-number-of-targets). This guarantees that the [deduplication](https://docs.victoriametrics.com/#deduplication) consistently leaves samples from the same `vmagent` replica.
 * BUGFIX: return the proper response stub from `/api/v1/query_exemplars` handler, which is needed for Grafana v8+. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1999).