postgres_exporter: expose stat_statements.include_query (#4372)

* refactor: added stat_statements component configuration

* test: added stat_statements to unmarshal test

* refactor: override kingpin flags to pass stat_statements flags

* docs(changelog): updated changelog (#4004)

* refactor: added stat_statements component configuration

* test: added stat_statements to unmarshal test

* refactor: override kingpin flags to pass stat_statements flags

* docs(changelog): updated changelog (#4004)

* docs(changelog): refined changelog entry (#4004)

* docs(reference): added stat_statements documentation

* docs(prostgres exporter): query length default is 120

* refactor(postgres exporter): namespaced stat statements config for integration #4004

* refactor(postgres exporter): renamed variable for clarity #4004

* test(postgres exporter): indent using spaces #4004

* docs(postgres exporter): format documentation #4004

Co-authored-by: Clayton Cornell <[email protected]>

* docs(postgres exporter): format documentation #4004

Co-authored-by: Clayton Cornell <[email protected]>

* docs(postgres exporter): format array

* refactor: added stat_statements component configuration

* test: added stat_statements to unmarshal test

* refactor: override kingpin flags to pass stat_statements flags

* docs(changelog): updated changelog (#4004)

* docs(changelog): refined changelog entry (#4004)

* docs(reference): added stat_statements documentation

* docs(prostgres exporter): query length default is 120

* refactor(postgres exporter): namespaced stat statements config for integration #4004

* refactor(postgres exporter): renamed variable for clarity #4004

* test(postgres exporter): indent using spaces #4004

* docs(postgres exporter): format array

* docs(postgres exporter): format documentation #4004

Co-authored-by: Clayton Cornell <[email protected]>

* test(postgres exporter): indent using tabs

* refactor(postgres exporter): check for errors when setting kingpin flags #4004

* docs(postgres exporter): typo in code documentation #4004

Co-authored-by: Cristian Greco <[email protected]>

* test(postgres exporter): added QueryLength default to expected postgres exporter integration config

* test(postgres exporter): converter includes empty stat_statements by default

* Revert "test(postgres exporter): converter includes empty stat_statements by default"

This reverts commit 2bc5c1a.

* refactor(postgres exporter): flattened namespaced config to match other components of same types #4004

* Revert "refactor(postgres exporter): flattened namespaced config to match other components of same types #4004"

This reverts commit 672fadc.

* make field nullable

* docs(postgres exporter): removed duplicate line #4004

* docs(changelog): moved to unreleased section

---------

Co-authored-by: Clayton Cornell <[email protected]>
Co-authored-by: Cristian Greco <[email protected]>

Author: 3 people

CHANGELOG.md

@@ -33,6 +33,8 @@ Main (unreleased)
 
 - Send remote config status to the remote server for the remotecfg service. (@erikbaranowski)
 
+- Add a `stat_statements` configuration block to the `prometheus.exporter.postgres` component to enable selecting both the query ID and the full SQL statement. The new block includes one option to enable statement selection, and another to configure the maximum length of the statement text. (@SimonSerrano) 
+
 ### Enhancements
 
 - Add support of `tls` in components `loki.source.(awsfirehose|gcplog|heroku|api)` and `prometheus.receive_http` and `pyroscope.receive_http`. (@fgouteroux)

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

@@ -126,6 +126,17 @@ If `enabled` is set to `true` and no allowlist or denylist is specified, the exp
 
 If `autodiscovery` is disabled, neither `database_allowlist` nor `database_denylist` has any effect.
 
+### `stat_statements`
+
+The `stat_statements` block configures the selection of both the query ID and the full SQL statement.
+This configuration takes effect only when the `stat_statements` collector is enabled.
+
+The following arguments are supported:
+| Name            | Type     | Description                                         | Default | Required |
+| --------------- | -------- | --------------------------------------------------- | ------- | -------- |
+| `include_query` | `bool`   | Enable the selection of query ID and SQL statement. | `false` | no       |
+| `query_length`  | `number` | Maximum length of the statement query text.         | `120`   | no       |
+
 ## Exported fields
 
 {{< docs/shared lookup="reference/components/exporter-component-exports.md" source="alloy" version="<ALLOY_VERSION>" >}}

internal/component/prometheus/exporter/postgres/postgres.go

@@ -38,6 +38,7 @@ var DefaultArguments = Arguments{
 	},
 	DisableDefaultMetrics:   false,
 	CustomQueriesConfigPath: "",
+	StatStatementFlags:      nil,
 }
 
 // Arguments configures the prometheus.exporter.postgres component
@@ -54,7 +55,8 @@ type Arguments struct {
 	EnabledCollectors       []string `alloy:"enabled_collectors,attr,optional"`
 
 	// Blocks
-	AutoDiscovery AutoDiscovery `alloy:"autodiscovery,block,optional"`
+	AutoDiscovery      AutoDiscovery       `alloy:"autodiscovery,block,optional"`
+	StatStatementFlags *StatStatementFlags `alloy:"stat_statements,block,optional"`
 }
 
 func (a *Arguments) Validate() error {
@@ -74,6 +76,12 @@ type AutoDiscovery struct {
 	DatabaseDenylist  []string `alloy:"database_denylist,attr,optional"`
 }
 
+// StatStatementFlags describe the flags to pass along the activation of the stat_statements collector
+type StatStatementFlags struct {
+	IncludeQuery bool `alloy:"include_query,attr,optional"`
+	QueryLength  uint `alloy:"query_length,attr,optional"`
+}
+
 // SetToDefault implements syntax.Defaulter.
 func (a *Arguments) SetToDefault() {
 	*a = DefaultArguments
@@ -90,6 +98,17 @@ func (a *Arguments) convert(instanceName string) *postgres_exporter.Config {
 		QueryPath:              a.CustomQueriesConfigPath,
 		Instance:               instanceName,
 		EnabledCollectors:      a.EnabledCollectors,
+		StatStatementFlags:     a.StatStatementFlags.Convert(),
+	}
+}
+
+func (s *StatStatementFlags) Convert() *postgres_exporter.StatStatementFlags {
+	if s == nil {
+		return nil
+	}
+	return &postgres_exporter.StatStatementFlags{
+		IncludeQuery: s.IncludeQuery,
+		QueryLength:  s.QueryLength,
 	}
 }
 

internal/component/prometheus/exporter/postgres/postgres_test.go

@@ -11,12 +11,17 @@ import (
 )
 
 func TestAlloyConfigUnmarshal(t *testing.T) {
-	var exampleAlloyConfig = `
+	exampleAlloyConfig := `
 	data_source_names = ["postgresql://username:password@localhost:5432/database?sslmode=disable"]
 	disable_settings_metrics = true
 	disable_default_metrics = true
 	custom_queries_config_path = "/tmp/queries.yaml"
-	
+
+	stat_statements {
+		include_query = true
+		query_length = 200
+	}
+
 	autodiscovery {
 		enabled = false
 		database_allowlist = ["include1"]
@@ -37,19 +42,23 @@ func TestAlloyConfigUnmarshal(t *testing.T) {
 		},
 		DisableDefaultMetrics:   true,
 		CustomQueriesConfigPath: "/tmp/queries.yaml",
+		StatStatementFlags: &StatStatementFlags{
+			IncludeQuery: true,
+			QueryLength:  200,
+		},
 	}
 
 	require.Equal(t, expected, args)
 }
 
 func TestAlloyConfigConvert(t *testing.T) {
-	var exampleAlloyConfig = `
+	exampleAlloyConfig := `
 	data_source_names = ["postgresql://username:password@localhost:5432/database?sslmode=disable"]
 	disable_settings_metrics = true
 	disable_default_metrics = false
 	custom_queries_config_path = "/tmp/queries.yaml"
 	enabled_collectors = ["collector1", "collector2"]
-	
+
 	autodiscovery {
 		enabled = false
 		database_allowlist = ["include1"]
@@ -72,12 +81,13 @@ func TestAlloyConfigConvert(t *testing.T) {
 		QueryPath:              "/tmp/queries.yaml",
 		Instance:               "test-instance",
 		EnabledCollectors:      []string{"collector1", "collector2"},
+		StatStatementFlags:     nil,
 	}
 	require.Equal(t, expected, *c)
 }
 
 func TestRiverConfigValidate(t *testing.T) {
-	var tc = []struct {
+	tc := []struct {
 		name        string
 		args        Arguments
 		expectedErr string

internal/static/integrations/postgres_exporter/postgres_exporter.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/alecthomas/kingpin/v2"
 	"github.com/go-kit/log"
 	"github.com/grafana/alloy/internal/runtime/logging"
 	"github.com/grafana/alloy/internal/static/integrations"
@@ -38,7 +39,14 @@ type Config struct {
 	// EnabledCollectors is a list of additional collectors to enable. NOTE: Due to limitations of the postgres_exporter,
 	// this is only used for the first DSN provided and only some collectors can be enabled/disabled this way. See the
 	// user-facing docs for more information.
-	EnabledCollectors []string
+	EnabledCollectors  []string
+	StatStatementFlags *StatStatementFlags
+}
+
+// Config for the stat_statement collector flags
+type StatStatementFlags struct {
+	IncludeQuery bool
+	QueryLength  uint
 }
 
 // Name returns the name of the integration this config is for.
@@ -173,6 +181,27 @@ func New(log log.Logger, cfg *Config) (integrations.Integration, error) {
 		return integrations.NewCollectorIntegration(cfg.Name(), integrations.WithCollectors(e)), nil
 	}
 
+	// This is a hack to force the command line flag values for the stat_statements collector.
+	// These flags are not exposed outside the package and cannot be mutated afterwards.
+	if cfg.StatStatementFlags != nil && cfg.StatStatementFlags.IncludeQuery {
+		includeQueryFlag := kingpin.CommandLine.GetFlag("collector.stat_statements.include_query")
+		queryLengthFlag := kingpin.CommandLine.GetFlag("collector.stat_statements.query_length")
+
+		if includeQueryFlag == nil || queryLengthFlag == nil {
+			return nil, fmt.Errorf("failed to find collector.stat_statements.include_query or collector.stat_statements.query_length in postgres_exporter")
+		}
+
+		err := includeQueryFlag.Model().Value.Set("true")
+		if err != nil {
+			return nil, fmt.Errorf("failed to set include query flag using Kingpin : %w", err)
+		}
+
+		err = queryLengthFlag.Model().Value.Set(fmt.Sprintf("%d", cfg.StatStatementFlags.QueryLength))
+		if err != nil {
+			return nil, fmt.Errorf("failed to set query length flag using Kingpin : %w", err)
+		}
+	}
+
 	// On top of the exporter's metrics, the postgres exporter also has metrics exposed via collector package.
 	// However, these can only work for the first DSN provided. This matches the current implementation of the exporter.
 	// TODO: Once https://github.com/prometheus-community/postgres_exporter/issues/999 is addressed, update the exporter