Allow the setting of labels for snmp exporter for both target and tar…

…gets (#1876)

* Allow the setting of labels for snmp exporter, both in the hardcoded manner and also in the labels manner.

* Simplify snmp exporter

* Add tests.

* Remove name.

* PR feedback

CHANGELOG.md

@@ -18,8 +18,11 @@ Main (unreleased)
 ### Features
 
 - Add the function `path_join` to the stdlib. (@wildum)
+
 - Add support to `loki.source.syslog` for the RFC3164 format ("BSD syslog"). (@sushain97)
+
 - Add support to `loki.source.api` to be able to extract the tenant from the HTTP `X-Scope-OrgID` header (@QuentinBisson)
+- 
 - (_Experimental_) Add a `loki.secretfilter` component to redact secrets from collected logs.
 
 ### Enhancements
@@ -31,6 +34,9 @@ Main (unreleased)
 
 - Fix an issue where some `faro.receiver` would drop multiple fields defined in `payload.meta.browser`, as fields were defined in the struct.
 
+- SNMP exporter now supports labels in both `target` and `targets` parameters. (@mattdurham)
+
+
 ### Bugfixes
 
 - Fixed a bug in `import.git` which caused a `"non-fast-forward update"` error message. (@ptodev)

docs/sources/reference/components/prometheus/prometheus.exporter.snmp.md

@@ -65,6 +65,8 @@ The following labels can be set to a target:
 * `auth`: The SNMP authentication profile to use.
 * `walk_params`: The config to use for this target.
 
+Any other labels defined are added to the scraped metrics.
+
 ## Blocks
 
 The following blocks are supported inside the definition of
@@ -83,13 +85,15 @@ The following blocks are supported inside the definition of
 The `target` block defines an individual SNMP target.
 The `target` block may be specified multiple times to define multiple targets. The label of the block is required and will be used in the target's `job` label.
 
-| Name           | Type     | Description                                                           | Default | Required |
-| -------------- | -------- | --------------------------------------------------------------------- | ------- | -------- |
-| `address`      | `string` | The address of SNMP device.                                           |         | yes      |
-| `module`       | `string` | SNMP module to use for polling.                                       | `""`    | no       |
-| `auth`         | `string` | SNMP authentication profile to use.                                   | `""`    | no       |
-| `walk_params`  | `string` | Config to use for this target.                                        | `""`    | no       |
-| `snmp_context` | `string` | Override the `context_name` parameter in the SNMP configuration file. | `""`    | no       |
+| Name           | Type          | Description                                                           | Default | Required |
+|----------------|---------------|-----------------------------------------------------------------------| ------- | -------- |
+| `address`      | `string`      | The address of SNMP device.                                           |         | yes      |
+| `module`       | `string`      | SNMP module to use for polling.                                       | `""`    | no       |
+| `auth`         | `string`      | SNMP authentication profile to use.                                   | `""`    | no       |
+| `walk_params`  | `string`      | Config to use for this target.                                        | `""`    | no       |
+| `snmp_context` | `string`      | Override the `context_name` parameter in the SNMP configuration file. | `""`    | no       |
+| `labels`       | `map(string)` | Map of labels to apply to all metrics captured from the target.       | `""`    | no       |
+
 
 ### walk_param block
 
@@ -136,6 +140,9 @@ prometheus.exporter.snmp "example" {
         address     = "192.168.1.2"
         module      = "if_mib"
         walk_params = "public"
+        labels = {
+            "env" = "dev",
+        }
     }
 
     target "network_router_2" {
@@ -227,6 +234,7 @@ prometheus.exporter.snmp "example" {
             "address"     = "192.168.1.2",
             "module"      = "if_mib",
             "walk_params" = "public",
+            "env"         = "dev",
         },
         {
             "name"        = "network_router_2",

internal/component/prometheus/exporter/snmp/snmp.go

@@ -3,6 +3,7 @@ package snmp
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"time"
 
 	"github.com/grafana/alloy/internal/component"
@@ -44,12 +45,17 @@ func buildSNMPTargets(baseTarget discovery.Target, args component.Arguments) []d
 
 	for _, tgt := range snmpTargets {
 		target := make(discovery.Target)
+		// Set extra labels first, meaning that any other labels will override
+		for k, v := range tgt.Labels {
+			target[k] = v
+		}
 		for k, v := range baseTarget {
 			target[k] = v
 		}
 
 		target["job"] = target["job"] + "/" + tgt.Name
 		target["__param_target"] = tgt.Target
+		target["__param_name"] = tgt.Name
 		if tgt.Module != "" {
 			target["__param_module"] = tgt.Module
 		}
@@ -71,12 +77,13 @@ func buildSNMPTargets(baseTarget discovery.Target, args component.Arguments) []d
 
 // SNMPTarget defines a target to be used by the exporter.
 type SNMPTarget struct {
-	Name        string `alloy:",label"`
-	Target      string `alloy:"address,attr"`
-	Module      string `alloy:"module,attr,optional"`
-	Auth        string `alloy:"auth,attr,optional"`
-	WalkParams  string `alloy:"walk_params,attr,optional"`
-	SNMPContext string `alloy:"snmp_context,attr,optional"`
+	Name        string            `alloy:",label"`
+	Target      string            `alloy:"address,attr"`
+	Module      string            `alloy:"module,attr,optional"`
+	Auth        string            `alloy:"auth,attr,optional"`
+	WalkParams  string            `alloy:"walk_params,attr,optional"`
+	SNMPContext string            `alloy:"snmp_context,attr,optional"`
+	Labels      map[string]string `alloy:"labels,attr,optional"`
 }
 
 type TargetBlock []SNMPTarget
@@ -92,6 +99,7 @@ func (t TargetBlock) Convert() []snmp_exporter.SNMPTarget {
 			Auth:        target.Auth,
 			WalkParams:  target.WalkParams,
 			SNMPContext: target.SNMPContext,
+			Labels:      target.Labels,
 		})
 	}
 	return targets
@@ -134,6 +142,22 @@ type Arguments struct {
 
 type TargetsList []map[string]string
 
+// target technically isnt required but its so overloaded within snmp I dont want it leaking.
+var ignoredLabels = []string{"name", "module", "auth", "walk_params", "snmp_context", "address", "__address__", "target"}
+
+func createUserLabels(t map[string]string) map[string]string {
+	// Need to create labels.
+	userLabels := make(map[string]string)
+	for k, v := range t {
+		// ignore the special labels
+		if slices.Contains(ignoredLabels, k) {
+			continue
+		}
+		userLabels[k] = v
+	}
+	return userLabels
+}
+
 func (t TargetsList) Convert() []snmp_exporter.SNMPTarget {
 	targets := make([]snmp_exporter.SNMPTarget, 0, len(t))
 	for _, target := range t {
@@ -145,6 +169,7 @@ func (t TargetsList) Convert() []snmp_exporter.SNMPTarget {
 			Auth:        target["auth"],
 			WalkParams:  target["walk_params"],
 			SNMPContext: target["snmp_context"],
+			Labels:      createUserLabels(target),
 		})
 	}
 	return targets
@@ -161,6 +186,7 @@ func (t TargetsList) convert() []SNMPTarget {
 			Auth:        target["auth"],
 			WalkParams:  target["walk_params"],
 			SNMPContext: target["snmp_context"],
+			Labels:      createUserLabels(target),
 		})
 	}
 	return targets

internal/component/prometheus/exporter/snmp/snmp_test.go

@@ -126,6 +126,21 @@ func TestConvertConfig(t *testing.T) {
 	require.Equal(t, "network_switch_1", res.SnmpTargets[0].Name)
 }
 
+func TestConfigLabels(t *testing.T) {
+	lbls := map[string]string{"env": "dev"}
+	args := Arguments{
+		ConfigFile: "modules.yml",
+		Targets:    TargetBlock{{Name: "network_switch_1", Target: "192.168.1.2", Module: "if_mib", Labels: lbls}},
+		WalkParams: WalkParams{{Name: "public", Retries: 2}},
+	}
+
+	res := args.Convert()
+	require.Equal(t, "modules.yml", res.SnmpConfigFile)
+	require.Equal(t, 1, len(res.SnmpTargets))
+	require.Equal(t, "network_switch_1", res.SnmpTargets[0].Name)
+	require.Equal(t, res.SnmpTargets[0].Labels["env"], "dev")
+}
+
 func TestConvertConfigWithInlineConfig(t *testing.T) {
 	args := Arguments{
 		ConfigStruct: config.Config{Modules: map[string]*config.Module{"if_mib": {Walk: []string{"1.3.6.1.2.1.2"}}}},
@@ -177,6 +192,32 @@ func TestConvertTargetsList(t *testing.T) {
 	require.Equal(t, "1.3.6.1.2.1.2", res[0].WalkParams)
 }
 
+func TestConvertTargetsListWithLabels(t *testing.T) {
+	targets := TargetsList{
+		{
+			"name":        "network_switch_1",
+			"address":     "192.168.1.2",
+			"module":      "if_mib",
+			"auth":        "public_v2",
+			"walk_params": "1.3.6.1.2.1.2",
+			"env":         "dev",
+			"app":         "falcon",
+		},
+	}
+
+	res := targets.Convert()
+	require.Equal(t, 1, len(res))
+	require.Equal(t, "network_switch_1", res[0].Name)
+	require.Equal(t, "192.168.1.2", res[0].Target)
+	require.Equal(t, "if_mib", res[0].Module)
+	require.Equal(t, "public_v2", res[0].Auth)
+	require.Equal(t, "1.3.6.1.2.1.2", res[0].WalkParams)
+	require.Len(t, res[0].Labels, 2)
+	require.Equal(t, "dev", res[0].Labels["env"])
+	require.Equal(t, "falcon", res[0].Labels["app"])
+
+}
+
 func TestConvertTargetsListAlternativeAddress(t *testing.T) {
 	targets := TargetsList{
 		{

internal/converter/internal/staticconvert/internal/build/snmp_exporter.go

@@ -25,6 +25,9 @@ func toSnmpExporter(config *snmp_exporter.Config) *snmp.Arguments {
 		target["auth"] = t.Auth
 		target["walk_params"] = t.WalkParams
 		target["snmp_context"] = t.SNMPContext
+		for k, v := range t.Labels {
+			target[k] = v
+		}
 		targets = append(targets, target)
 	}
 

internal/static/integrations/snmp_exporter/snmp_exporter.go

@@ -33,6 +33,7 @@ type SNMPTarget struct {
 	Auth        string `yaml:"auth"`
 	WalkParams  string `yaml:"walk_params,omitempty"`
 	SNMPContext string `yaml:"snmp_context,omitempty"`
+	Labels      map[string]string
 }
 
 // Config configures the SNMP integration.