Merge pull request prometheus-community#491 from roidelapluie/switch-to-go-kit

Switch to go-kit log and enable TLS/Basic auth

Author: SuperQ

README.md

@@ -36,10 +36,6 @@ To build the Docker image:
 
 This will build the docker image as `prometheuscommunity/postgres_exporter:${branch}`.
 
-### Vendoring
-
-Package vendoring is handled with Go modules.
-
 ### Flags
 
 * `help`
@@ -78,11 +74,14 @@ Package vendoring is handled with Go modules.
  A list of databases to remove when autoDiscoverDatabases is enabled.
 
 * `log.level`
- Set logging level: one of `debug`, `info`, `warn`, `error`, `fatal`
+ Set logging level: one of `debug`, `info`, `warn`, `error`.
 
 * `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`.
+ Set the log format: one of `logfmt`, `json`.
+
+* `web.config.file`
+ Configuration file to use TLS and/or basic authentication. The format of the
+ file is described [in the exporter-toolkit repository](https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md).
 
 ### Environment Variables
 

cmd/postgres_exporter/pg_setting.go

@@ -19,13 +19,13 @@ import (
 "strconv"
 "strings"
 
+"github.com/go-kit/kit/log/level"
 "github.com/prometheus/client_golang/prometheus"
-"github.com/prometheus/common/log"
 )
 
 // Query the pg_settings view containing runtime variables
 func querySettings(ch chan<- prometheus.Metric, server *Server) error {
-log.Debugf("Querying pg_setting view on %q", server)
+level.Debug(logger).Log("msg", "Querying pg_setting view", "server", server)
 
 // pg_settings docs: https://www.postgresql.org/docs/current/static/view-pg-settings.html
 //

cmd/postgres_exporter/postgres_exporter.go

@@ -31,11 +31,16 @@ import (
 "time"
 
 "github.com/blang/semver"
+"github.com/go-kit/kit/log"
+"github.com/go-kit/kit/log/level"
 "github.com/lib/pq"
 "github.com/prometheus/client_golang/prometheus"
 "github.com/prometheus/client_golang/prometheus/promhttp"
-"github.com/prometheus/common/log"
+"github.com/prometheus/common/promlog"
+"github.com/prometheus/common/promlog/flag"
 "github.com/prometheus/common/version"
+"github.com/prometheus/exporter-toolkit/web"
+webflag "github.com/prometheus/exporter-toolkit/web/kingpinflag"
 "gopkg.in/alecthomas/kingpin.v2"
 "gopkg.in/yaml.v2"
 )
@@ -58,6 +63,7 @@ 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()
+webConfig = webflag.AddFlags(kingpin.CommandLine)
 metricPath = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").Envar("PG_EXPORTER_WEB_TELEMETRY_PATH").String()
 disableDefaultMetrics = kingpin.Flag("disable-default-metrics", "Do not include default metrics.").Default("false").Envar("PG_EXPORTER_DISABLE_DEFAULT_METRICS").Bool()
 disableSettingsMetrics = kingpin.Flag("disable-settings-metrics", "Do not include pg_settings metrics.").Default("false").Envar("PG_EXPORTER_DISABLE_SETTINGS_METRICS").Bool()
@@ -67,6 +73,7 @@ var (
 constantLabelsList = kingpin.Flag("constantLabels", "A list of label=value separated by comma(,).").Default("").Envar("PG_EXPORTER_CONSTANT_LABELS").String()
 excludeDatabases = kingpin.Flag("exclude-databases", "A list of databases to remove when autoDiscoverDatabases is enabled").Default("").Envar("PG_EXPORTER_EXCLUDE_DATABASES").String()
 metricPrefix = kingpin.Flag("metric-prefix", "A metric prefix can be used to have non-default (not \"pg\") prefixes for each of the metrics").Default("pg").Envar("PG_EXPORTER_METRIC_PREFIX").String()
+logger = log.NewNopLogger()
 )
 
 // Metric name parts.
@@ -516,7 +523,7 @@ func makeQueryOverrideMap(pgVersion semver.Version, queryOverrides map[string][]
 }
 }
 if !matched {
-log.Warnln("No query matched override for", name, "- disabling metric space.")
+level.Warn(logger).Log("msg", "No query matched override, disabling metric space", "name", name)
 resultMap[name] = ""
 }
 }
@@ -537,7 +544,7 @@ func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[str
 newQueryOverrides := make(map[string]string)
 
 for metric, specs := range userQueries {
-log.Debugln("New user metric namespace from YAML:", metric, "Will cache results for:", specs.CacheSeconds)
+level.Debug(logger).Log("msg", "New user metric namespace from YAML metric", "metric", metric, "cache_seconds", specs.CacheSeconds)
 newQueryOverrides[metric] = specs.Query
 metricMap, ok := metricMaps[metric]
 if !ok {
@@ -589,9 +596,9 @@ func addQueries(content []byte, pgVersion semver.Version, server *Server) error
 for k, v := range partialExporterMap {
 _, found := server.metricMap[k]
 if found {
-log.Debugln("Overriding metric", k, "from user YAML file.")
+level.Debug(logger).Log("msg", "Overriding metric from user YAML file", "metric", k)
 } else {
-log.Debugln("Adding new metric", k, "from user YAML file.")
+level.Debug(logger).Log("msg", "Adding new metric from user YAML file", "metric", k)
 }
 server.metricMap[k] = v
 }
@@ -600,9 +607,9 @@ func addQueries(content []byte, pgVersion semver.Version, server *Server) error
 for k, v := range newQueryOverrides {
 _, found := server.queryOverrides[k]
 if found {
-log.Debugln("Overriding query override", k, "from user YAML file.")
+level.Debug(logger).Log("msg", "Overriding query override from user YAML file", "query_override", k)
 } else {
-log.Debugln("Adding new query override", k, "from user YAML file.")
+level.Debug(logger).Log("msg", "Adding new query override from user YAML file", "query_override", k)
 }
 server.queryOverrides[k] = v
 }
@@ -633,7 +640,7 @@ func makeDescMap(pgVersion semver.Version, serverLabels prometheus.Labels, metri
 if !columnMapping.supportedVersions(pgVersion) {
 // It's very useful to be able to see what columns are being
 // rejected.
-log.Debugln(columnName, "is being forced to discard due to version incompatibility.")
+level.Debug(logger).Log("msg", "Column is being forced to discard due to version incompatibility", "column", columnName)
 thisMap[columnName] = MetricMap{
 discard: true,
 conversion: func(_ interface{}) (float64, bool) {
@@ -720,7 +727,7 @@ func makeDescMap(pgVersion semver.Version, serverLabels prometheus.Labels, metri
 case string:
 durationString = t
 default:
-log.Errorln("DURATION conversion metric was not a string")
+level.Error(logger).Log("msg", "Duration conversion metric was not a string")
 return math.NaN(), false
 }
 
@@ -730,7 +737,7 @@ func makeDescMap(pgVersion semver.Version, serverLabels prometheus.Labels, metri
 
 d, err := time.ParseDuration(durationString)
 if err != nil {
-log.Errorln("Failed converting result to metric:", columnName, in, err)
+level.Error(logger).Log("msg", "Failed converting result to metric", "column", columnName, "in", in, "err", err)
 return math.NaN(), false
 }
 return float64(d / time.Millisecond), true
@@ -793,14 +800,14 @@ func dbToFloat64(t interface{}) (float64, bool) {
 strV := string(v)
 result, err := strconv.ParseFloat(strV, 64)
 if err != nil {
-log.Infoln("Could not parse []byte:", err)
+level.Info(logger).Log("msg", "Could not parse []byte", "err", err)
 return math.NaN(), false
 }
 return result, true
 case string:
 result, err := strconv.ParseFloat(v, 64)
 if err != nil {
-log.Infoln("Could not parse string:", err)
+level.Info(logger).Log("msg", "Could not parse string", "err", err)
 return math.NaN(), false
 }
 return result, true
@@ -833,14 +840,14 @@ func dbToUint64(t interface{}) (uint64, bool) {
 strV := string(v)
 result, err := strconv.ParseUint(strV, 10, 64)
 if err != nil {
-log.Infoln("Could not parse []byte:", err)
+level.Info(logger).Log("msg", "Could not parse []byte", "err", err)
 return 0, false
 }
 return result, true
 case string:
 result, err := strconv.ParseUint(v, 10, 64)
 if err != nil {
-log.Infoln("Could not parse string:", err)
+level.Info(logger).Log("msg", "Could not parse string", "err", err)
 return 0, false
 }
 return result, true
@@ -980,7 +987,7 @@ func NewServer(dsn string, opts ...ServerOpt) (*Server, error) {
 db.SetMaxOpenConns(1)
 db.SetMaxIdleConns(1)
 
-log.Infof("Established new database connection to %q.", fingerprint)
+level.Info(logger).Log("msg", "Established new database connection", "fingerprint", fingerprint)
 
 s := &Server{
 db: db,
@@ -1007,7 +1014,7 @@ func (s *Server) Close() error {
 func (s *Server) Ping() error {
 if err := s.db.Ping(); err != nil {
 if cerr := s.Close(); cerr != nil {
-log.Errorf("Error while closing non-pinging DB connection to %q: %v", s, cerr)
+level.Error(logger).Log("msg", "Error while closing non-pinging DB connection", "server", s, "err", cerr)
 }
 return err
 }
@@ -1093,7 +1100,7 @@ func (s *Servers) Close() {
 defer s.m.Unlock()
 for _, server := range s.servers {
 if err := server.Close(); err != nil {
-log.Errorf("failed to close connection to %q: %v", server, err)
+level.Error(logger).Log("msg", "Failed to close connection", "server", server, "err", err)
 }
 }
 }
@@ -1178,7 +1185,7 @@ func parseConstLabels(s string) prometheus.Labels {
 for _, p := range parts {
 keyValue := strings.Split(strings.TrimSpace(p), "=")
 if len(keyValue) != 2 {
-log.Errorf(`Wrong constant labels format %q, should be "key=value"`, p)
+level.Error(logger).Log(`Wrong constant labels format, should be "key=value"`, "input", p)
 continue
 }
 key := strings.TrimSpace(keyValue[0])
@@ -1457,10 +1464,10 @@ func queryNamespaceMappings(ch chan<- prometheus.Metric, server *Server) map[str
 scrapeStart := time.Now()
 
 for namespace, mapping := range server.metricMap {
-log.Debugln("Querying namespace: ", namespace)
+level.Debug(logger).Log("msg", "Querying namespace", "namespace", namespace)
 
 if mapping.master && !server.master {
-log.Debugln("Query skipped...")
+level.Debug(logger).Log("msg", "Query skipped...")
 continue
 }
 
@@ -1469,7 +1476,7 @@ func queryNamespaceMappings(ch chan<- prometheus.Metric, server *Server) map[str
 serVersion, _ := semver.Parse(server.lastMapVersion.String())
 runServerRange, _ := semver.ParseRange(server.runonserver)
 if !runServerRange(serVersion) {
-log.Debugln("Query skipped for database version: ", server.lastMapVersion.String(), " as it should be run on database server version: ", server.runonserver)
+level.Debug(logger).Log("msg", "Query skipped for this database version", "version", server.lastMapVersion.String(), "target_version", server.runonserver)
 continue
 }
 }
@@ -1500,12 +1507,12 @@ func queryNamespaceMappings(ch chan<- prometheus.Metric, server *Server) map[str
 // Serious error - a namespace disappeared
 if err != nil {
 namespaceErrors[namespace] = err
-log.Infoln(err)
+level.Info(logger).Log("err", err)
 }
 // Non-serious errors - likely version or parsing problems.
 if len(nonFatalErrors) > 0 {
 for _, err := range nonFatalErrors {
-log.Infoln(err.Error())
+level.Info(logger).Log("err", err)
 }
 }
 
@@ -1532,7 +1539,7 @@ func queryNamespaceMappings(ch chan<- prometheus.Metric, server *Server) map[str
 
 // Check and update the exporters query maps if the version has changed.
 func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server) error {
-log.Debugf("Querying Postgres Version on %q", server)
+level.Debug(logger).Log("msg", "Querying PostgreSQL version", "server", server)
 versionRow := server.db.QueryRow("SELECT version();")
 var versionString string
 err := versionRow.Scan(&versionString)
@@ -1544,12 +1551,12 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 return fmt.Errorf("Error parsing version string on %q: %v", server, err)
 }
 if !e.disableDefaultMetrics && semanticVersion.LT(lowestSupportedVersion) {
-log.Warnf("PostgreSQL version is lower on %q then our lowest supported version! Got %s minimum supported is %s.", server, semanticVersion, lowestSupportedVersion)
+level.Warn(logger).Log("msg", "PostgreSQL version is lower than our lowest supported version", "server", server, "version", semanticVersion, "lowest_supported_version", lowestSupportedVersion)
 }
 
 // Check if semantic version changed and recalculate maps if needed.
 if semanticVersion.NE(server.lastMapVersion) || server.metricMap == nil {
-log.Infof("Semantic Version Changed on %q: %s -> %s", server, server.lastMapVersion, semanticVersion)
+level.Info(logger).Log("msg", "Semantic version changed", "server", server, "from", server.lastMapVersion, "to", semanticVersion)
 server.mappingMtx.Lock()
 
 // Get Default Metrics only for master database
@@ -1570,13 +1577,13 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 // Calculate the hashsum of the useQueries
 userQueriesData, err := ioutil.ReadFile(e.userQueriesPath)
 if err != nil {
-log.Errorln("Failed to reload user queries:", e.userQueriesPath, err)
+level.Error(logger).Log("msg", "Failed to reload user queries", "path", e.userQueriesPath, "err", err)
 e.userQueriesError.WithLabelValues(e.userQueriesPath, "").Set(1)
 } else {
 hashsumStr := fmt.Sprintf("%x", sha256.Sum256(userQueriesData))
 
 if err := addQueries(userQueriesData, semanticVersion, server); err != nil {
-log.Errorln("Failed to reload user queries:", e.userQueriesPath, err)
+level.Error(logger).Log("msg", "Failed to reload user queries", "path", e.userQueriesPath, "err", err)
 e.userQueriesError.WithLabelValues(e.userQueriesPath, hashsumStr).Set(1)
 } else {
 // Mark user queries as successfully loaded
@@ -1618,7 +1625,7 @@ func (e *Exporter) scrape(ch chan<- prometheus.Metric) {
 if err := e.scrapeDSN(ch, dsn); err != nil {
 errorsCount++
 
-log.Errorf(err.Error())
+level.Error(logger).Log("err", err)
 
 if _, ok := err.(*ErrorConnectToServer); ok {
 connectionErrorsCount++
@@ -1656,19 +1663,19 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 var err error
 dsnURI, err = url.Parse(dsn)
 if err != nil {
-log.Errorf("Unable to parse DSN as URI (%s): %v", loggableDSN(dsn), err)
+level.Error(logger).Log("msg", "Unable to parse DSN as URI", "dsn", loggableDSN(dsn), "err", err)
 continue
 }
 } else if connstringRe.MatchString(dsn) {
 dsnConnstring = dsn
 } else {
-log.Errorf("Unable to parse DSN as either URI or connstring (%s)", loggableDSN(dsn))
+level.Error(logger).Log("msg", "Unable to parse DSN as either URI or connstring", "dsn", loggableDSN(dsn))
 continue
 }
 
 server, err := e.servers.GetServer(dsn)
 if err != nil {
-log.Errorf("Error opening connection to database (%s): %v", loggableDSN(dsn), err)
+level.Error(logger).Log("msg", "Error opening connection to database", "dsn", loggableDSN(dsn), "err", err)
 continue
 }
 dsns[dsn] = struct{}{}
@@ -1678,7 +1685,7 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 
 databaseNames, err := queryDatabases(server)
 if err != nil {
-log.Errorf("Error querying databases (%s): %v", loggableDSN(dsn), err)
+level.Error(logger).Log("msg", "Error querying databases", "dsn", loggableDSN(dsn), "err", err)
 continue
 }
 for _, databaseName := range databaseNames {
@@ -1722,7 +1729,7 @@ func (e *Exporter) scrapeDSN(ch chan<- prometheus.Metric, dsn string) error {
 
 // 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)
+level.Warn(logger).Log("msg", "Proceeding with outdated query maps, as the Postgres version could not be determined", "err", err)
 }
 
 return server.Scrape(ch, e.disableSettingsMetrics)
@@ -1790,8 +1797,10 @@ func contains(a []string, x string) bool {
 
 func main() {
 kingpin.Version(fmt.Sprintf("postgres_exporter %s (built with %s)\n", Version, runtime.Version()))
-log.AddFlags(kingpin.CommandLine)
+promlogConfig := &promlog.Config{}
+flag.AddFlags(kingpin.CommandLine, promlogConfig)
 kingpin.Parse()
+logger = promlog.New(promlogConfig)
 
 // landingPage contains the HTML served at '/'.
 // TODO: Make this nicer and more informative.
@@ -1811,11 +1820,13 @@ func main() {
 
 dsn, err := getDataSources()
 if err != nil {
-log.Fatalf("failed reading data sources: %s", err.Error())
+level.Error(logger).Log("msg", "Failed reading data sources", "err", err.Error())
+os.Exit(1)
 }
 
 if len(dsn) == 0 {
-log.Fatal("couldn't find environment variables describing the datasource to use")
+level.Error(logger).Log("msg", "Couldn't find environment variables describing the datasource to use")
+os.Exit(1)
 }
 
 opts := []ExporterOpt{
@@ -1847,6 +1858,10 @@ func main() {
 w.Write(landingPage) // nolint: errcheck
 })
 
-log.Infof("Starting Server: %s", *listenAddress)
-log.Fatal(http.ListenAndServe(*listenAddress, nil))
+level.Info(logger).Log("msg", "Listening on address", "address", *listenAddress)
+srv := &http.Server{Addr: *listenAddress}
+if err := web.ListenAndServe(srv, *webConfig, logger); err != nil {
+level.Error(logger).Log("msg", "Error running HTTP server", "err", err)
+os.Exit(1)
+}
 }

go.mod

@@ -4,10 +4,12 @@ go 1.14
 
 require (
 github.com/blang/semver v3.5.1+incompatible
+github.com/go-kit/kit v0.10.0
 github.com/lib/pq v1.9.0
 github.com/prometheus/client_golang v1.9.0
 github.com/prometheus/client_model v0.2.0
 github.com/prometheus/common v0.17.0
+github.com/prometheus/exporter-toolkit v0.5.1
 gopkg.in/alecthomas/kingpin.v2 v2.2.6
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
 gopkg.in/yaml.v2 v2.4.0