lib/promrelabel: add keep_if_contains and drop_if_contains relabeling actions

docs/CHANGELOG.md

@@ -32,6 +32,7 @@ The sandbox cluster installation is running under the constant load generated by
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add support for reading and writing samples via [Google PubSub](https://cloud.google.com/pubsub). See [these docs](https://docs.victoriametrics.com/vmagent.html#google-pubsub-integration).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add support for Datadog `/api/v2/series` and `/api/beta/sketches` ingestion protocols to vmagent/vminsert components. See this [doc](https://docs.victoriametrics.com/#how-to-send-data-from-datadog-agent) for examples. Thanks to @AndrewChubatiuk for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5094).
 * FEATURE: reduce the default value for `-import.maxLineLen` command-line flag from 100MB to 10MB in order to prevent excessive memory usage during data import via [/api/v1/import](https://docs.victoriametrics.com/#how-to-import-data-in-json-line-format).
+* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add `keep_if_contains` and `drop_if_contains` relabeling actions. See [these docs](https://docs.victoriametrics.com/vmagent.html#relabeling-enhancements) for details.
 * FEATURE: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): add [day_of_year()](https://docs.victoriametrics.com/MetricsQL.html#day_of_year) function, which returns the day of the year for each of the given unix timestamps. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5345) for details. Thanks to @luckyxiaoqiang for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5368/).
 
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): prevent from `FATAL: cannot flush metainfo` panic when [`-remoteWrite.multitenantURL`](https://docs.victoriametrics.com/vmagent.html#multitenancy) command-line flag is set. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5357).

docs/vmagent.md

@@ -639,6 +639,26 @@ The following articles contain useful information about Prometheus relabeling:
       source_labels: ["instance", "host"]
     ```
 
+  * `keep_if_contains`: keeps the entry if `target_label` contains all the label values listed in `source_labels`,
+    while dropping all the other entries. For example, the following relabeling config keeps targets
+    if `__meta_consul_tags` contains value from the `required_consul_tag` label:
+
+    ```yaml
+    - action: keep_if_contains
+      target_label: __meta_consul_tags
+      source_labels: [required_consul_tag]
+    ```
+
+  * `drop_if_contains`: drops the entry if `target_label` contains all the label values listed in `source_labels`,
+    while keeping all the other entries. For example, the following relabeling config drops targets
+    if `__meta_consul_tag` contains value from the `denied_consul_tag` label:
+
+    ```yaml
+    - action: drop_if_contains
+      target_label: __meta_consul_tags
+      source_labels: [denied_consul_tag]
+    ```
+
   * `keep_metrics`: keeps all the metrics with names matching the given `regex`,
     while dropping all the other metrics. For example, the following relabeling config keeps metrics
     with `foo` and `bar` names, while dropping all the other metrics:

lib/promrelabel/config.go

@@ -291,6 +291,26 @@ func parseRelabelConfig(rc *RelabelConfig) (*parsedRelabelConfig, error) {
 		if targetLabel == "" {
 			return nil, fmt.Errorf("missing `target_label` for `action=replace_all`")
 		}
+	case "keep_if_contains":
+		if targetLabel == "" {
+			return nil, fmt.Errorf("`target_label` must be set for `action=keep_if_containes`")
+		}
+		if len(sourceLabels) == 0 {
+			return nil, fmt.Errorf("`source_labels` must contain at least a single entry for `action=keep_if_contains`")
+		}
+		if rc.Regex != nil {
+			return nil, fmt.Errorf("`regex` cannot be used for `action=keep_if_contains`")
+		}
+	case "drop_if_contains":
+		if targetLabel == "" {
+			return nil, fmt.Errorf("`target_label` must be set for `action=drop_if_containes`")
+		}
+		if len(sourceLabels) == 0 {
+			return nil, fmt.Errorf("`source_labels` must contain at least a single entry for `action=drop_if_contains`")
+		}
+		if rc.Regex != nil {
+			return nil, fmt.Errorf("`regex` cannot be used for `action=drop_if_contains`")
+		}
 	case "keep_if_equal":
 		if len(sourceLabels) < 2 {
 			return nil, fmt.Errorf("`source_labels` must contain at least two entries for `action=keep_if_equal`; got %q", sourceLabels)

lib/promrelabel/config_test.go

@@ -251,6 +251,62 @@ func TestParseRelabelConfigsFailure(t *testing.T) {
 			},
 		})
 	})
+	t.Run("keep_if_contains-missing-target-label", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:       "keep_if_contains",
+				SourceLabels: []string{"foo"},
+			},
+		})
+	})
+	t.Run("keep_if_contains-missing-source-labels", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:      "keep_if_contains",
+				TargetLabel: "foo",
+			},
+		})
+	})
+	t.Run("keep_if_contains-unused-regex", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:       "keep_if_contains",
+				TargetLabel:  "foo",
+				SourceLabels: []string{"bar"},
+				Regex: &MultiLineRegex{
+					S: "bar",
+				},
+			},
+		})
+	})
+	t.Run("drop_if_contains-missing-target-label", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:       "drop_if_contains",
+				SourceLabels: []string{"foo"},
+			},
+		})
+	})
+	t.Run("drop_if_contains-missing-source-labels", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:      "drop_if_contains",
+				TargetLabel: "foo",
+			},
+		})
+	})
+	t.Run("drop_if_contains-unused-regex", func(t *testing.T) {
+		f([]RelabelConfig{
+			{
+				Action:       "drop_if_contains",
+				TargetLabel:  "foo",
+				SourceLabels: []string{"bar"},
+				Regex: &MultiLineRegex{
+					S: "bar",
+				},
+			},
+		})
+	})
 	t.Run("keep_if_equal-missing-source-labels", func(t *testing.T) {
 		f([]RelabelConfig{
 			{

lib/promrelabel/relabel.go

@@ -256,6 +256,32 @@ func (prc *parsedRelabelConfig) apply(labels []prompbmarshal.Label, labelsOffset
 			labels = setLabelValue(labels, labelsOffset, prc.TargetLabel, valueStr)
 		}
 		return labels
+	case "keep_if_contains":
+		// Keep the entry if target_label contains all the label values listed in source_labels.
+		// For example, the following relabeling rule would leave the entry if __meta_consul_tags
+		// contains values of __meta_required_tag1 and __meta_required_tag2:
+		//
+		//   - action: keep_if_contains
+		//     target_label: __meta_consul_tags
+		//     source_labels: [__meta_required_tag1, __meta_required_tag2]
+		//
+		if containsAllLabelValues(src, prc.TargetLabel, prc.SourceLabels) {
+			return labels
+		}
+		return labels[:labelsOffset]
+	case "drop_if_contains":
+		// Drop the entry if target_label contains all the label values listed in source_labels.
+		// For example, the following relabeling rule would drop the entry if __meta_consul_tags
+		// contains values of __meta_required_tag1 and __meta_required_tag2:
+		//
+		//   - action: drop_if_contains
+		//     target_label: __meta_consul_tags
+		//     source_labels: [__meta_required_tag1, __meta_required_tag2]
+		//
+		if containsAllLabelValues(src, prc.TargetLabel, prc.SourceLabels) {
+			return labels[:labelsOffset]
+		}
+		return labels
 	case "keep_if_equal":
 		// Keep the entry if all the label values in source_labels are equal.
 		// For example:
@@ -489,6 +515,17 @@ func (prc *parsedRelabelConfig) expandCaptureGroups(template, source string, mat
 
 var relabelBufPool bytesutil.ByteBufferPool
 
+func containsAllLabelValues(labels []prompbmarshal.Label, targetLabel string, sourceLabels []string) bool {
+	targetLabelValue := getLabelValue(labels, targetLabel)
+	for _, sourceLabel := range sourceLabels {
+		v := getLabelValue(labels, sourceLabel)
+		if !strings.Contains(targetLabelValue, v) {
+			return false
+		}
+	}
+	return true
+}
+
 func areEqualLabelValues(labels []prompbmarshal.Label, labelNames []string) bool {
 	if len(labelNames) < 2 {
 		logger.Panicf("BUG: expecting at least 2 labelNames; got %d", len(labelNames))

lib/promrelabel/relabel_test.go

@@ -383,6 +383,104 @@ func TestParsedRelabelConfigsApply(t *testing.T) {
   target_label: foo
   replacement: "foobar"
 `, `{}`, true, `{foo="foobar"}`)
+	})
+	t.Run("keep_if_contains-non-existing-target-and-source", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{x="y"}`, true, `{x="y"}`)
+	})
+	t.Run("keep_if_contains-non-existing-target", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa"}`, true, `{}`)
+	})
+	t.Run("keep_if_contains-non-existing-source", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{foo="aaa"}`, true, `{foo="aaa"}`)
+	})
+	t.Run("keep_if_contains-matching-source-target", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa",foo="aaa"}`, true, `{bar="aaa",foo="aaa"}`)
+	})
+	t.Run("keep_if_contains-matching-sources-target", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar, baz]
+`, `{bar="aaa",foo="aaa",baz="aaa"}`, true, `{bar="aaa",baz="aaa",foo="aaa"}`)
+	})
+	t.Run("keep_if_contains-mismatching-source-target", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa",foo="bbb"}`, true, `{}`)
+	})
+	t.Run("keep_if_contains-mismatching-sources-target", func(t *testing.T) {
+		f(`
+- action: keep_if_contains
+  target_label: foo
+  source_labels: [bar, baz]
+`, `{bar="aaa",foo="aaa",baz="bbb"}`, true, `{}`)
+	})
+	t.Run("drop_if_contains-non-existing-target-and-source", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{x="y"}`, true, `{}`)
+	})
+	t.Run("drop_if_contains-non-existing-target", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa"}`, true, `{bar="aaa"}`)
+	})
+	t.Run("drop_if_contains-non-existing-source", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{foo="aaa"}`, true, `{}`)
+	})
+	t.Run("drop_if_contains-matching-source-target", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa",foo="aaa"}`, true, `{}`)
+	})
+	t.Run("drop_if_contains-matching-sources-target", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar, baz]
+`, `{bar="aaa",foo="aaa",baz="aaa"}`, true, `{}`)
+	})
+	t.Run("drop_if_contains-mismatching-source-target", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar]
+`, `{bar="aaa",foo="bbb"}`, true, `{bar="aaa",foo="bbb"}`)
+	})
+	t.Run("drop_if_contains-mismatching-sources-target", func(t *testing.T) {
+		f(`
+- action: drop_if_contains
+  target_label: foo
+  source_labels: [bar, baz]
+`, `{bar="aaa",foo="aaa",baz="bbb"}`, true, `{bar="aaa",baz="bbb",foo="aaa"}`)
 	})
 	t.Run("keep_if_equal-miss", func(t *testing.T) {
 		f(`