Merge pull request #4 from form3tech-oss/english-pull-upstream

Pull in upstream to v0.8.0

Author: english

README.md

@@ -43,6 +43,9 @@ Package vendoring is handled with [`govendor`](https://github.com/kardianos/gove
 
 ### Flags
 
+* `help`
+  Show context-sensitive help (also try --help-long and --help-man).
+
 * `web.listen-address`
   Address to listen on for web interface and telemetry. Default is `:9187`.
 
@@ -55,6 +58,9 @@ Package vendoring is handled with [`govendor`](https://github.com/kardianos/gove
 * `disable-settings-metrics`
   Use the flag if you don't want to scrape `pg_settings`.
 
+* `auto-discover-databases`
+  Whether to discover the databases on a server dynamically.
+
 * `extend.query-path`
   Path to a YAML file containing custom queries to run. Check out [`queries.yaml`](queries.yaml)
   for examples of the format.
@@ -63,16 +69,22 @@ Package vendoring is handled with [`govendor`](https://github.com/kardianos/gove
   Do not run - print the internal representation of the metric maps. Useful when debugging a custom
   queries file.
 
+* `constantLabels`
+  Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
+
+* `version`
+  Show application version.
+
+* `exclude-databases`
+  A list of databases to remove when autoDiscoverDatabases is enabled.
+
 * `log.level`
   Set logging level: one of `debug`, `info`, `warn`, `error`, `fatal`
 
 * `log.format`
   Set the log output target and format. e.g. `logger:syslog?appname=bob&local=7` or `logger:stdout?json=true`
   Defaults to `logger:stderr`.
 
-* `constantLabels`
-  Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
-
 ### Environment Variables
 
 The following environment variables configure the exporter:
@@ -85,6 +97,9 @@ The following environment variables configure the exporter:
    an alternative to `DATA_SOURCE_NAME` which exclusively accepts the raw URI
    without a username and password component.
 
+* `DATA_SOURCE_URI_FILE`
+   The same as above but reads the URI from a file.
+
 * `DATA_SOURCE_USER`
   When using `DATA_SOURCE_URI`, this environment variable is used to specify
   the username.
@@ -111,13 +126,19 @@ The following environment variables configure the exporter:
 * `PG_EXPORTER_DISABLE_SETTINGS_METRICS`
   Use the flag if you don't want to scrape `pg_settings`. Value can be `true` or `false`. Defauls is `false`.
 
+* `PG_EXPORTER_AUTO_DISCOVER_DATABASES`
+  Whether to discover the databases on a server dynamically. Value can be `true` or `false`. Defauls is `false`.
+
 * `PG_EXPORTER_EXTEND_QUERY_PATH`
   Path to a YAML file containing custom queries to run. Check out [`queries.yaml`](queries.yaml)
   for examples of the format.
 
 * `PG_EXPORTER_CONSTANT_LABELS`
   Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
 
+* `PG_EXPORTER_EXCLUDE_DATABASES`
+  A comma-separated list of databases to remove when autoDiscoverDatabases is enabled. Default is empty string.
+
 Settings set by environment variables starting with `PG_` will be overwritten by the corresponding CLI flag if given.
 
 ### Setting the Postgres server's data source name
@@ -163,7 +184,7 @@ flag. This removes all built-in metrics, and uses only metrics defined by querie
 
 ### Automatically discover databases
 To scrape metrics from all databases on a database server, the database DSN's can be dynamically discovered via the 
-`--auto-discover-databases` flag. When true, `SELECT datname FROM pg_database WHERE datallowconn = true AND datistemplate = false` is run for all configured DSN's. From the 
+`--auto-discover-databases` flag. When true, `SELECT datname FROM pg_database WHERE datallowconn = true AND datistemplate = false and datname != current_database()` is run for all configured DSN's. From the 
 result a new set of DSN's is created for which the metrics are scraped.
 
 In addition, the option `--exclude-databases` adds the possibily to filter the result from the auto discovery to discard databases you do not need.

cmd/postgres_exporter/postgres_exporter.go

@@ -23,13 +23,26 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/log"
+	"github.com/prometheus/common/version"
 	"gopkg.in/alecthomas/kingpin.v2"
 	"gopkg.in/yaml.v2"
 )
 
+// Branch is set during build to the git branch.
+var Branch string
+
+// BuildDate is set during build to the ISO-8601 date and time.
+var BuildDate string
+
+// Revision is set during build to the git commit revision.
+var Revision string
+
 // Version is set during build to the git describe version
 // (semantic version)-(commitish) form.
-var Version = "0.0.1"
+var Version = "0.0.1-rev"
+
+// VersionShort is set during build to the semantic version.
+var VersionShort = "0.0.1"
 
 var (
 	listenAddress          = kingpin.Flag("web.listen-address", "Address to listen on for web interface and telemetry.").Default(":9187").Envar("PG_EXPORTER_WEB_LISTEN_ADDRESS").String()
@@ -101,6 +114,7 @@ type Mapping map[string]MappingOptions
 type UserQuery struct {
 	Query        string    `yaml:"query"`
 	Metrics      []Mapping `yaml:"metrics"`
+	Master       bool      `yaml:"master"`        // Querying only for master database
 	CacheSeconds uint64    `yaml:"cache_seconds"` // Number of seconds to cache the namespace result metrics for.
 }
 
@@ -140,13 +154,15 @@ func (cm *ColumnMapping) UnmarshalYAML(unmarshal func(interface{}) error) error
 // This is mainly so we can parse cacheSeconds around.
 type intermediateMetricMap struct {
 	columnMappings map[string]ColumnMapping
+	master         bool
 	cacheSeconds   uint64
 }
 
 // MetricMapNamespace groups metric maps under a shared set of labels.
 type MetricMapNamespace struct {
 	labels         []string             // Label names for this namespace
 	columnMappings map[string]MetricMap // Column mappings in this namespace
+	master         bool                 // Call query only for master database
 	cacheSeconds   uint64               // Number of seconds this metric namespace can be cached. 0 disables.
 }
 
@@ -190,6 +206,23 @@ func dumpMaps() {
 }
 
 var builtinMetricMaps = map[string]intermediateMetricMap{
+	"pg_stat_bgwriter": {
+		map[string]ColumnMapping{
+			"checkpoints_timed":     {COUNTER, "Number of scheduled checkpoints that have been performed", nil, nil},
+			"checkpoints_req":       {COUNTER, "Number of requested checkpoints that have been performed", nil, nil},
+			"checkpoint_write_time": {COUNTER, "Total amount of time that has been spent in the portion of checkpoint processing where files are written to disk, in milliseconds", nil, nil},
+			"checkpoint_sync_time":  {COUNTER, "Total amount of time that has been spent in the portion of checkpoint processing where files are synchronized to disk, in milliseconds", nil, nil},
+			"buffers_checkpoint":    {COUNTER, "Number of buffers written during checkpoints", nil, nil},
+			"buffers_clean":         {COUNTER, "Number of buffers written by the background writer", nil, nil},
+			"maxwritten_clean":      {COUNTER, "Number of times the background writer stopped a cleaning scan because it had written too many buffers", nil, nil},
+			"buffers_backend":       {COUNTER, "Number of buffers written directly by a backend", nil, nil},
+			"buffers_backend_fsync": {COUNTER, "Number of times a backend had to execute its own fsync call (normally the background writer handles those even when the backend does its own write)", nil, nil},
+			"buffers_alloc":         {COUNTER, "Number of buffers allocated", nil, nil},
+			"stats_reset":           {COUNTER, "Time at which these statistics were last reset", nil, nil},
+		},
+		true,
+		0,
+	},
 	"pg_stat_database": {
 		map[string]ColumnMapping{
 			"datid":          {LABEL, "OID of a database", nil, nil},
@@ -212,6 +245,7 @@ var builtinMetricMaps = map[string]intermediateMetricMap{
 			"blk_write_time": {COUNTER, "Time spent writing data file blocks by backends in this database, in milliseconds", nil, nil},
 			"stats_reset":    {COUNTER, "Time at which these statistics were last reset", nil, nil},
 		},
+		true,
 		0,
 	},
 	"pg_stat_database_conflicts": {
@@ -224,6 +258,7 @@ var builtinMetricMaps = map[string]intermediateMetricMap{
 			"confl_bufferpin":  {COUNTER, "Number of queries in this database that have been canceled due to pinned buffers", nil, nil},
 			"confl_deadlock":   {COUNTER, "Number of queries in this database that have been canceled due to deadlocks", nil, nil},
 		},
+		true,
 		0,
 	},
 	"pg_locks": {
@@ -232,6 +267,7 @@ var builtinMetricMaps = map[string]intermediateMetricMap{
 			"mode":    {LABEL, "Type of Lock", nil, nil},
 			"count":   {GAUGE, "Number of locks", nil, nil},
 		},
+		true,
 		0,
 	},
 	"pg_stat_replication": {
@@ -277,6 +313,21 @@ var builtinMetricMaps = map[string]intermediateMetricMap{
 			"flush_lag":                {DISCARD, "Time elapsed between flushing recent WAL locally and receiving notification that this standby server has written and flushed it (but not yet applied it). This can be used to gauge the delay that synchronous_commit level remote_flush incurred while committing if this server was configured as a synchronous standby.", nil, semver.MustParseRange(">=10.0.0")},
 			"replay_lag":               {DISCARD, "Time elapsed between flushing recent WAL locally and receiving notification that this standby server has written, flushed and applied it. This can be used to gauge the delay that synchronous_commit level remote_apply incurred while committing if this server was configured as a synchronous standby.", nil, semver.MustParseRange(">=10.0.0")},
 		},
+		true,
+		0,
+	},
+	"pg_stat_archiver": {
+		map[string]ColumnMapping{
+			"archived_count":     {COUNTER, "Number of WAL files that have been successfully archived", nil, nil},
+			"last_archived_wal":  {DISCARD, "Name of the last WAL file successfully archived", nil, nil},
+			"last_archived_time": {DISCARD, "Time of the last successful archive operation", nil, nil},
+			"failed_count":       {COUNTER, "Number of failed attempts for archiving WAL files", nil, nil},
+			"last_failed_wal":    {DISCARD, "Name of the WAL file of the last failed archival operation", nil, nil},
+			"last_failed_time":   {DISCARD, "Time of the last failed archival operation", nil, nil},
+			"stats_reset":        {DISCARD, "Time at which these statistics were last reset", nil, nil},
+			"last_archive_age":   {GAUGE, "Time in seconds since last WAL segment was successfully archived", nil, nil},
+		},
+		true,
 		0,
 	},
 	"pg_stat_activity": {
@@ -286,6 +337,7 @@ var builtinMetricMaps = map[string]intermediateMetricMap{
 			"count":           {GAUGE, "number of connections in this state", nil, nil},
 			"max_tx_duration": {GAUGE, "max duration in seconds any active transaction has been running", nil, nil},
 		},
+		true,
 		0,
 	},
 }
@@ -356,6 +408,17 @@ var queryOverrides = map[string][]OverrideQuery{
 		},
 	},
 
+	"pg_stat_archiver": {
+		{
+			semver.MustParseRange(">=0.0.0"),
+			`
+			SELECT *,
+				extract(epoch from now() - last_archived_time) AS last_archive_age
+			FROM pg_stat_archiver
+			`,
+		},
+	},
+
 	"pg_stat_activity": {
 		// This query only works
 		{
@@ -445,6 +508,7 @@ func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[str
 			newMetricMap := make(map[string]ColumnMapping)
 			metricMap = intermediateMetricMap{
 				columnMappings: newMetricMap,
+				master:         specs.Master,
 				cacheSeconds:   specs.CacheSeconds,
 			}
 			metricMaps[metric] = metricMap
@@ -615,7 +679,7 @@ func makeDescMap(pgVersion semver.Version, serverLabels prometheus.Labels, metri
 			}
 		}
 
-		metricMap[namespace] = MetricMapNamespace{variableLabels, thisMap, intermediateMappings.cacheSeconds}
+		metricMap[namespace] = MetricMapNamespace{variableLabels, thisMap, intermediateMappings.master, intermediateMappings.cacheSeconds}
 	}
 
 	return metricMap
@@ -858,7 +922,7 @@ func (s *Server) Scrape(ch chan<- prometheus.Metric, disableSettingsMetrics bool
 
 	var err error
 
-	if (!disableSettingsMetrics && !*autoDiscoverDatabases) || (!disableSettingsMetrics && *autoDiscoverDatabases && s.master) {
+	if !disableSettingsMetrics && s.master {
 		if err = querySettings(ch, s); err != nil {
 			err = fmt.Errorf("error retrieving settings: %s", err)
 		}
@@ -1258,6 +1322,12 @@ func queryNamespaceMappings(ch chan<- prometheus.Metric, server *Server) map[str
 
 	for namespace, mapping := range server.metricMap {
 		log.Debugln("Querying namespace: ", namespace)
+
+		if mapping.master && !server.master {
+			log.Debugln("Query skipped...")
+			continue
+		}
+
 		scrapeMetric := false
 		// Check if the metric is cached
 		server.cacheMtx.Lock()
@@ -1336,12 +1406,13 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 		log.Infof("Semantic Version Changed on %q: %s -> %s", server, server.lastMapVersion, semanticVersion)
 		server.mappingMtx.Lock()
 
-		if e.disableDefaultMetrics || (!e.disableDefaultMetrics && e.autoDiscoverDatabases && !server.master) {
-			server.metricMap = make(map[string]MetricMapNamespace)
-			server.queryOverrides = make(map[string]string)
-		} else {
+		// Get Default Metrics only for master database
+		if !e.disableDefaultMetrics && server.master {
 			server.metricMap = makeDescMap(semanticVersion, server.labels, e.builtinMetricMaps)
 			server.queryOverrides = makeQueryOverrideMap(semanticVersion, queryOverrides)
+		} else {
+			server.metricMap = make(map[string]MetricMapNamespace)
+			server.queryOverrides = make(map[string]string)
 		}
 
 		server.lastMapVersion = semanticVersion
@@ -1371,11 +1442,11 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 		server.mappingMtx.Unlock()
 	}
 
-	// Output the version as a special metric
+	// Output the version as a special metric only for master database
 	versionDesc := prometheus.NewDesc(fmt.Sprintf("%s_%s", namespace, staticLabelName),
 		"Version string as reported by postgres", []string{"version", "short_version"}, server.labels)
 
-	if !e.disableDefaultMetrics && (server.master && e.autoDiscoverDatabases) {
+	if !e.disableDefaultMetrics && server.master {
 		ch <- prometheus.MustNewConstMetric(versionDesc,
 			prometheus.UntypedValue, 1, versionString, semanticVersion.String())
 	}
@@ -1440,6 +1511,7 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 			continue
 		}
 
+		// If autoDiscoverDatabases is true, set first dsn as master database (Default: false)
 		server.master = true
 
 		databaseNames, err := queryDatabases(server)
@@ -1468,10 +1540,16 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 
 func (e *Exporter) scrapeDSN(ch chan<- prometheus.Metric, dsn string) error {
 	server, err := e.servers.GetServer(dsn)
+
 	if err != nil {
 		return &ErrorConnectToServer{fmt.Sprintf("Error opening connection to database (%s): %s", loggableDSN(dsn), err.Error())}
 	}
 
+	// Check if autoDiscoverDatabases is false, set dsn as master database (Default: false)
+	if !e.autoDiscoverDatabases {
+		server.master = true
+	}
+
 	// Check if map versions need to be updated
 	if err := e.checkMapVersions(ch, server); err != nil {
 		log.Warnln("Proceeding with outdated query maps, as the Postgres version could not be determined:", err)
@@ -1522,6 +1600,7 @@ func getDataSources() []string {
 	if len(dsn) == 0 {
 		var user string
 		var pass string
+		var uri string
 
 		if len(os.Getenv("DATA_SOURCE_USER_FILE")) != 0 {
 			fileContents, err := ioutil.ReadFile(os.Getenv("DATA_SOURCE_USER_FILE"))
@@ -1559,7 +1638,17 @@ func getDataSources() []string {
 		}
 
 		ui := url.UserPassword(user, pass).String()
-		uri := os.Getenv("DATA_SOURCE_URI")
+
+		if len(os.Getenv("DATA_SOURCE_URI_FILE")) != 0 {
+			fileContents, err := ioutil.ReadFile(os.Getenv("DATA_SOURCE_URI_FILE"))
+			if err != nil {
+				panic(err)
+			}
+			uri = strings.TrimSpace(string(fileContents))
+		} else {
+			uri = os.Getenv("DATA_SOURCE_URI")
+		}
+
 		dsn = "postgresql://" + ui + "@" + uri
 
 		return []string{dsn}
@@ -1614,6 +1703,13 @@ func main() {
 		exporter.servers.Close()
 	}()
 
+	// Setup build info metric.
+	version.Branch = Branch
+	version.BuildDate = BuildDate
+	version.Revision = Revision
+	version.Version = VersionShort
+	prometheus.MustRegister(version.NewCollector("postgres_exporter"))
+
 	prometheus.MustRegister(exporter)
 
 	http.Handle(*metricPath, promhttp.Handler())

cmd/postgres_exporter/postgres_exporter_integration_test.go

@@ -117,6 +117,7 @@ func (s *IntegrationSuite) TestUnknownMetricParsingDoesntCrash(c *C) {
 	for k := range exporter.builtinMetricMaps {
 		emptyMaps[k] = intermediateMetricMap{
 			map[string]ColumnMapping{},
+			true,
 			0,
 		}
 	}

cmd/postgres_exporter/postgres_exporter_test.go

@@ -32,6 +32,7 @@ func (s *FunctionalSuite) TestSemanticVersionColumnDiscard(c *C) {
 				"metric_which_stays":    {COUNTER, "This metric should not be eliminated", nil, nil},
 				"metric_which_discards": {COUNTER, "This metric should be forced to DISCARD", nil, nil},
 			},
+			true,
 			0,
 		},
 	}