Exporter configuration file (#231)

Signed-off-by: Anders Swanson <[email protected]>

Author: anders-swanson

README.md

@@ -558,6 +558,8 @@ The following command line arguments (flags) can be passed to the exporter (the
 
 ```bash
 Usage of oracledb_exporter:
+      --config.file="example-config.yaml"
+                                 File with metrics exporter configuration.  (env: CONFIG_FILE)
       --web.telemetry-path="/metrics"
                                  Path under which to expose metrics. (env: TELEMETRY_PATH)
       --default.metrics="default-metrics.toml"
@@ -597,6 +599,69 @@ You may provide the connection details using these variables:
 
 The following example puts the logfile in the current location with the filename `alert.log` and loads the default matrics file (`default-metrics,toml`) from the current location.
 
+If you prefer to provide configuration via a [config file](./example-config.yaml), you may do so with the `--config.file` argument. The use of a config file over command line arguments is preferred. If a config file is not provided, the default database connection is managed by command line arguments.
+
+```yaml
+# Example Oracle Database Metrics Exporter Configuration file.
+# Environment variables of the form ${VAR_NAME} will be expanded.
+
+databases:
+  ## Path on which metrics will be served
+  # metricsPath: /metrics
+  ## Database connection information for the "default" database.
+  default:
+    ## Database username
+    username: ${DB_USERNAME}
+    ## Database password
+    password: ${DB_PASSWORD}
+    ## Database connection url
+    url: localhost:1521/freepdb1
+    ## Metrics scrape interval for this database
+    scrapeInterval: 15s
+    ## Metrics query timeout for this database, in seconds
+    queryTimeout: 5
+
+    ## Rely on Oracle Database External Authentication by network or OS
+    # externalAuth: false
+    ## Database role
+    # role: SYSDBA
+    ## Path to Oracle Database wallet, if using wallet
+    # tnsAdmin: /path/to/database/wallet
+
+    ### Connection settings:
+    ### Either the go-sql or Oracle Database connection pool may be used.
+    ### To use the Oracle Database connection pool over the go-sql connection pool,
+    ### set maxIdleConns to zero and configure the pool* settings.
+
+    ### Connection pooling settings for the go-sql connection pool
+    ## Max open connections for this database using go-sql connection pool
+    maxOpenConns: 10
+    ## Max idle connections for this database using go-sql connection pool
+    maxIdleConns: 10
+
+    ### Connection pooling settings for the Oracle Database connection pool
+    ## Oracle Database connection pool increment.
+    # poolIncrement: 1
+    ## Oracle Database Connection pool maximum size
+    # poolMaxConnections: 15
+    ## Oracle Database Connection pool minimum size
+    # poolMinConnections: 15
+
+metrics:
+  default: default-metrics.toml
+  #
+  custom:
+    - custom-metrics-example/custom-metrics.toml
+
+log:
+  # Path of log file
+  destination: /opt/alert.log
+  # Interval of log updates
+  interval: 15s
+  ## Set disable to 1 to disable logging
+  # disable: 0
+```
+
 ```shell
 ./oracledb_exporter --log.destination="./alert.log" --default.metrics="./default-metrics.toml"
 ```

collector/collector.go

@@ -49,14 +49,14 @@ func maskDsn(dsn string) string {
 }
 
 // NewExporter creates a new Exporter instance
-func NewExporter(logger *slog.Logger, cfg *Config) (*Exporter, error) {
+func NewExporter(logger *slog.Logger, m *MetricsConfiguration) (*Exporter, error) {
+	// TODO: support multiple databases
+	var cfg DatabaseConfig
+	for _, v := range m.Databases {
+		cfg = v
+	}
 	e := &Exporter{
-		mu:            &sync.Mutex{},
-		user:          cfg.User,
-		password:      cfg.Password,
-		connectString: cfg.ConnectString,
-		configDir:     cfg.ConfigDir,
-		externalAuth:  cfg.ExternalAuth,
+		mu: &sync.Mutex{},
 		duration: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace: namespace,
 			Subsystem: exporterName,
@@ -91,10 +91,10 @@ func NewExporter(logger *slog.Logger, cfg *Config) (*Exporter, error) {
 			Name:      "dbtype",
 			Help:      "Type of database the exporter is connected to (0=non-CDB, 1=CDB, >1=PDB).",
 		}),
-		logger:         logger,
-		config:         cfg,
-		lastScraped:    map[string]*time.Time{},
-		scrapeInterval: cfg.ScrapeInterval,
+		logger:               logger,
+		databaseConfig:       cfg,
+		metricsConfiguration: m,
+		lastScraped:          map[string]*time.Time{},
 	}
 	e.metricsToScrape = e.DefaultMetrics()
 	err := e.connect()
@@ -133,7 +133,7 @@ func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 	// they are running scheduled scrapes we should only scrape new data
 	// on the interval
-	if e.scrapeInterval != 0 {
+	if e.databaseConfig.ScrapeInterval != 0 {
 		// read access must be checked
 		e.mu.Lock()
 		for _, r := range e.scrapeResults {
@@ -160,7 +160,7 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 func (e *Exporter) RunScheduledScrapes(ctx context.Context) {
 	e.doScrape(time.Now())
 
-	ticker := time.NewTicker(e.scrapeInterval)
+	ticker := time.NewTicker(e.databaseConfig.ScrapeInterval)
 	defer ticker.Stop()
 
 	for {
@@ -236,7 +236,7 @@ func (e *Exporter) scrape(ch chan<- prometheus.Metric, tick *time.Time) {
 
 	e.dbtypeGauge.Set(float64(e.dbtype))
 
-	e.logger.Debug("Successfully pinged Oracle database: " + maskDsn(e.connectString))
+	e.logger.Debug("Successfully pinged Oracle database: " + maskDsn(e.databaseConfig.URL))
 	e.up.Set(1)
 
 	if e.checkIfMetricsChanged() {
@@ -323,43 +323,43 @@ func (e *Exporter) afterScrape(begun time.Time, countMetrics int, errChan chan e
 }
 
 func (e *Exporter) connect() error {
-	e.logger.Debug("Launching connection to " + maskDsn(e.connectString))
+	e.logger.Debug("Launching connection to " + maskDsn(e.databaseConfig.URL))
 
 	var P godror.ConnectionParams
 	// If password is not specified, externalAuth will be true and we'll ignore user input
-	e.externalAuth = e.password == ""
-	e.logger.Debug(fmt.Sprintf("external authentication set to %t", e.externalAuth))
+	e.databaseConfig.ExternalAuth = e.databaseConfig.Password == ""
+	e.logger.Debug(fmt.Sprintf("external authentication set to %t", e.databaseConfig.ExternalAuth))
 	msg := "Using Username/Password Authentication."
-	if e.externalAuth {
+	if e.databaseConfig.ExternalAuth {
 		msg = "Database Password not specified; will attempt to use external authentication (ignoring user input)."
-		e.user = ""
+		e.databaseConfig.Username = ""
 	}
 	e.logger.Info(msg)
 	externalAuth := sql.NullBool{
-		Bool:  e.externalAuth,
+		Bool:  e.databaseConfig.ExternalAuth,
 		Valid: true,
 	}
-	P.Username, P.Password, P.ConnectString, P.ExternalAuth = e.user, godror.NewPassword(e.password), e.connectString, externalAuth
+	P.Username, P.Password, P.ConnectString, P.ExternalAuth = e.databaseConfig.Username, godror.NewPassword(e.databaseConfig.Password), e.databaseConfig.URL, externalAuth
 
-	if e.config.PoolIncrement > 0 {
-		e.logger.Debug(fmt.Sprintf("set pool increment to %d", e.config.PoolIncrement))
-		P.PoolParams.SessionIncrement = e.config.PoolIncrement
+	if e.databaseConfig.PoolIncrement > 0 {
+		e.logger.Debug(fmt.Sprintf("set pool increment to %d", e.databaseConfig.PoolIncrement))
+		P.PoolParams.SessionIncrement = e.databaseConfig.PoolIncrement
 	}
-	if e.config.PoolMaxConnections > 0 {
-		e.logger.Debug(fmt.Sprintf("set pool max connections to %d", e.config.PoolMaxConnections))
-		P.PoolParams.MaxSessions = e.config.PoolMaxConnections
+	if e.databaseConfig.PoolMaxConnections > 0 {
+		e.logger.Debug(fmt.Sprintf("set pool max connections to %d", e.databaseConfig.PoolMaxConnections))
+		P.PoolParams.MaxSessions = e.databaseConfig.PoolMaxConnections
 	}
-	if e.config.PoolMinConnections > 0 {
-		e.logger.Debug(fmt.Sprintf("set pool min connections to %d", e.config.PoolMinConnections))
-		P.PoolParams.MinSessions = e.config.PoolMinConnections
+	if e.databaseConfig.PoolMinConnections > 0 {
+		e.logger.Debug(fmt.Sprintf("set pool min connections to %d", e.databaseConfig.PoolMinConnections))
+		P.PoolParams.MinSessions = e.databaseConfig.PoolMinConnections
 	}
 
 	P.PoolParams.WaitTimeout = time.Second * 5
 
 	// if TNS_ADMIN env var is set, set ConfigDir to that location
-	P.ConfigDir = e.configDir
+	P.ConfigDir = e.databaseConfig.TNSAdmin
 
-	switch e.config.DbRole {
+	switch e.databaseConfig.Role {
 	case "SYSDBA":
 		P.AdminRole = dsn.SysDBA
 	case "SYSOPER":
@@ -381,12 +381,12 @@ func (e *Exporter) connect() error {
 	// note that this just configures the connection, it does not actually connect until later
 	// when we call db.Ping()
 	db := sql.OpenDB(godror.NewConnector(P))
-	e.logger.Debug(fmt.Sprintf("set max idle connections to %d", e.config.MaxIdleConns))
-	db.SetMaxIdleConns(e.config.MaxIdleConns)
-	e.logger.Debug(fmt.Sprintf("set max open connections to %d", e.config.MaxOpenConns))
-	db.SetMaxOpenConns(e.config.MaxOpenConns)
+	e.logger.Debug(fmt.Sprintf("set max idle connections to %d", e.databaseConfig.MaxIdleConns))
+	db.SetMaxIdleConns(e.databaseConfig.MaxIdleConns)
+	e.logger.Debug(fmt.Sprintf("set max open connections to %d", e.databaseConfig.MaxOpenConns))
+	db.SetMaxOpenConns(e.databaseConfig.MaxOpenConns)
 	db.SetConnMaxLifetime(0)
-	e.logger.Debug(fmt.Sprintf("Successfully configured connection to %s", maskDsn(e.connectString)))
+	e.logger.Debug(fmt.Sprintf("Successfully configured connection to %s", maskDsn(e.databaseConfig.URL)))
 	e.db = db
 
 	if _, err := db.Exec(`
@@ -417,7 +417,7 @@ func (e *Exporter) GetDB() *sql.DB {
 }
 
 func (e *Exporter) checkIfMetricsChanged() bool {
-	for i, _customMetrics := range strings.Split(e.config.CustomMetrics, ",") {
+	for i, _customMetrics := range e.metricsConfiguration.Metrics.Custom {
 		if len(_customMetrics) == 0 {
 			continue
 		}
@@ -458,8 +458,8 @@ func (e *Exporter) reloadMetrics() {
 	e.metricsToScrape.Metric = defaultMetrics.Metric
 
 	// If custom metrics, load it
-	if strings.Compare(e.config.CustomMetrics, "") != 0 {
-		for _, _customMetrics := range strings.Split(e.config.CustomMetrics, ",") {
+	if len(e.metricsConfiguration.Metrics.Custom) > 0 {
+		for _, _customMetrics := range e.metricsConfiguration.Metrics.Custom {
 			metrics := &Metrics{}
 			if _, err := toml.DecodeFile(_customMetrics, metrics); err != nil {
 				e.logger.Error("failed to load custom metrics", "error", err)