app/vmselect/promql: add now() function, which returns the current timestamp as a floating-point value in seconds

app/vmselect/promql/exec_test.go

@@ -1017,6 +1017,17 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run("now()", func(t *testing.T) {
+		t.Parallel()
+		q := `round(now()/now())`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run("pi()", func(t *testing.T) {
 		t.Parallel()
 		q := `pi()`
@@ -7412,6 +7423,7 @@ func TestExecError(t *testing.T) {
 	f(`rand_normal(123, 456)`)
 	f(`rand_exponential(122, 456)`)
 	f(`pi(123)`)
+	f(`now(123)`)
 	f(`label_copy()`)
 	f(`label_move()`)
 	f(`median_over_time()`)

app/vmselect/promql/transform.go

@@ -74,6 +74,7 @@ var transformFuncs = map[string]transformFunc{
 	"log10":                newTransformFuncOneArg(transformLog10),
 	"minute":               newTransformFuncDateTime(transformMinute),
 	"month":                newTransformFuncDateTime(transformMonth),
+	"now":                  transformNow,
 	"pi":                   transformPi,
 	"prometheus_buckets":   transformPrometheusBuckets,
 	"rad":                  newTransformFuncOneArg(transformRad),
@@ -2045,6 +2046,14 @@ func transformPi(tfa *transformFuncArg) ([]*timeseries, error) {
 	return evalNumber(tfa.ec, math.Pi), nil
 }
 
+func transformNow(tfa *transformFuncArg) ([]*timeseries, error) {
+	if err := expectTransformArgsNum(tfa.args, 0); err != nil {
+		return nil, err
+	}
+	now := float64(time.Now().UnixNano()) / 1e9
+	return evalNumber(tfa.ec, now), nil
+}
+
 func bitmapAnd(a, b uint64) uint64 {
 	return a & b
 }

docs/CHANGELOG.md

@@ -6,6 +6,7 @@ sort: 15
 
 ## tip
 
+* FEATURE: add `now()` function to MetricsQL. This function returns the current timestamp in seconds. See [these docs](https://docs.victoriametrics.com/MetricsQL.html#now).
 * FEATURE: vmauth: allow using optional `name` field in configs. This field is then used as `username` label value for `vmauth_user_requests_total` metric. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1805).
 * FEATURE: [vmbackup](https://docs.victoriametrics.com/vmbackup.html), [vmrestore](https://docs.victoriametrics.com/vmrestore.html): add `-s3ForcePathStyle` command-line flag, which can be used for making backups to [Aliyun OSS](https://www.aliyun.com/product/oss). See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1802).
 

docs/MetricsQL.md

@@ -507,6 +507,10 @@ See also [implicit query conversions](#implicit-query-conversions).
 
 `month(q)` returns the month for every point of every time series returned by `q`. It is expected that `q` returns unix timestamps. The returned values are in the range `[1...12]`, where `1` means January and `12` means December. Metric names are stripped from the resulting series. This function is supported by PromQL.
 
+#### now
+
+`now()` returns the current timestamp as a floating-point value in seconds. See also [time](#time).
+
 #### pi
 
 `pi()` returns [Pi number](https://en.wikipedia.org/wiki/Pi). This function is supported by PromQL.

go.mod

@@ -8,7 +8,7 @@ require (
 	// like https://github.com/valyala/fasthttp/commit/996610f021ff45fdc98c2ce7884d5fa4e7f9199b
 	github.com/VictoriaMetrics/fasthttp v1.1.0
 	github.com/VictoriaMetrics/metrics v1.18.1
-	github.com/VictoriaMetrics/metricsql v0.30.1
+	github.com/VictoriaMetrics/metricsql v0.31.0
 	github.com/VividCortex/ewma v1.2.0 // indirect
 	github.com/aws/aws-sdk-go v1.42.6
 	github.com/census-instrumentation/opencensus-proto v0.3.0 // indirect

go.sum

@@ -108,8 +108,8 @@ github.com/VictoriaMetrics/fasthttp v1.1.0/go.mod h1:/7DMcogqd+aaD3G3Hg5kFgoFwlR
 github.com/VictoriaMetrics/metrics v1.12.2/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
 github.com/VictoriaMetrics/metrics v1.18.1 h1:OZ0+kTTto8oPfHnVAnTOoyl0XlRhRkoQrD2n2cOuRw0=
 github.com/VictoriaMetrics/metrics v1.18.1/go.mod h1:ArjwVz7WpgpegX/JpB0zpNF2h2232kErkEnzH1sxMmA=
-github.com/VictoriaMetrics/metricsql v0.30.1 h1:WFRNNocJsU6h98f7fkthHkMH1xwmcVSP2eSAap9FpTc=
+github.com/VictoriaMetrics/metricsql v0.31.0 h1:7cpjby64WVcRNBiMieEytuvAcU/jOOz+39RLigENz4E=
-github.com/VictoriaMetrics/metricsql v0.30.1/go.mod h1:ylO7YITho/Iw6P71oEaGyHbO94bGoGtzWfLGqFhMIg8=
+github.com/VictoriaMetrics/metricsql v0.31.0/go.mod h1:ylO7YITho/Iw6P71oEaGyHbO94bGoGtzWfLGqFhMIg8=
 github.com/VividCortex/ewma v1.1.1/go.mod h1:2Tkkvm3sRDVXaiyucHiACn4cqf7DpdyLvmxzcbUokwA=
 github.com/VividCortex/ewma v1.2.0 h1:f58SaIzcDXrSy3kWaHNvuJgJ3Nmz59Zji6XoJR/q1ow=
 github.com/VividCortex/ewma v1.2.0/go.mod h1:nz4BbCtbLyFDeC9SUHbtcT5644juEuWfUAUnGx7j5l4=

vendor/github.com/VictoriaMetrics/metricsql/transform.go

@@ -61,6 +61,7 @@ var transformFuncs = map[string]bool{
 	"log10":                true,
 	"minute":               true,
 	"month":                true,
+	"now":                  true,
 	"pi":                   true,
 	"prometheus_buckets":   true,
 	"rad":                  true,

vendor/modules.txt

@@ -21,7 +21,7 @@ github.com/VictoriaMetrics/fasthttp/stackless
 # github.com/VictoriaMetrics/metrics v1.18.1
 ## explicit
 github.com/VictoriaMetrics/metrics
-# github.com/VictoriaMetrics/metricsql v0.30.1
+# github.com/VictoriaMetrics/metricsql v0.31.0
 ## explicit
 github.com/VictoriaMetrics/metricsql
 github.com/VictoriaMetrics/metricsql/binaryop