Add client factory

arunvelsriram · Aug 9, 2020 · 4854e02 · 4854e02
1 parent ee1fd1f
commit 4854e02
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Showing 4 changed files with 68 additions and 39 deletions.
diff --git a/pkg/client/factory.go b/pkg/client/factory.go
@@ -0,0 +1,21 @@
+package client
+
+import "github.com/arunvelsriram/sftp-exporter/pkg/config"
+
+type (
+	Factory interface {
+		SFTPClient() (SFTPClient, error)
+	}
+
+	factory struct {
+		config config.Config
+	}
+)
+
+func (p factory) SFTPClient() (SFTPClient, error) {
+	return newSFTPClient(p.config)
+}
+
+func NewFactory(c config.Config) Factory {
+	return factory{c}
+}
diff --git a/pkg/client/sftp_client.go b/pkg/client/sftp_client.go
@@ -10,18 +10,45 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-type SFTPClient interface {
-	Close()
-	FSStat() (*model.FSStat, error)
+type (
+	SFTPClient interface {
+		Close()
+		FSStat() (*model.FSStat, error)
+	}
+
+	defaultSFTPClient struct {
+		sshClient  *ssh.Client
+		sftpClient *sftp.Client
+		config     config.Config
+	}
+)
+
+func (d defaultSFTPClient) Close() {
+	if err := d.sftpClient.Close(); err != nil {
+		log.WithFields(log.Fields{
+			"event": "closing SFTP connection"},
+		).Error(err)
+	}
+	if err := d.sshClient.Close(); err != nil {
+		log.WithFields(log.Fields{
+			"event": "closing SSH connection"},
+		).Error(err)
+	}
 }
 
-type defaultSFTPClient struct {
-	sshClient  *ssh.Client
-	sftpClient *sftp.Client
-	config     config.Config
+func (d defaultSFTPClient) FSStat() (*model.FSStat, error) {
+	statVFS, err := d.sftpClient.StatVFS("/upload")
+	if err != nil {
+		return nil, err
+	}
+
+	return &model.FSStat{
+		TotalSpace: float64(statVFS.TotalSpace()),
+		FreeSpace:  float64(statVFS.FreeSpace()),
+	}, nil
 }
 
-func NewSFTPClient(cfg config.Config) (SFTPClient, error) {
+func newSFTPClient(cfg config.Config) (SFTPClient, error) {
 	addr := fmt.Sprintf("%s:%d", cfg.GetSFTPHost(), cfg.GetSFTPPort())
 	clientConfig := &ssh.ClientConfig{
 		User: cfg.GetSFTPUser(),
@@ -52,28 +79,3 @@ func NewSFTPClient(cfg config.Config) (SFTPClient, error) {
 		config:     cfg,
 	}, nil
 }
-
-func (d defaultSFTPClient) Close() {
-	if err := d.sftpClient.Close(); err != nil {
-		log.WithFields(log.Fields{
-			"event": "closing SFTP connection"},
-		).Error(err)
-	}
-	if err := d.sshClient.Close(); err != nil {
-		log.WithFields(log.Fields{
-			"event": "closing SSH connection"},
-		).Error(err)
-	}
-}
-
-func (d defaultSFTPClient) FSStat() (*model.FSStat, error) {
-	statVFS, err := d.sftpClient.StatVFS("/upload")
-	if err != nil {
-		return nil, err
-	}
-
-	return &model.FSStat{
-		TotalSpace: float64(statVFS.TotalSpace()),
-		FreeSpace:  float64(statVFS.FreeSpace()),
-	}, nil
-}
diff --git a/pkg/collector/sftp_collector.go b/pkg/collector/sftp_collector.go
@@ -33,15 +33,16 @@ var (
 )
 
 type SFTPCollector struct {
-	config config.Config
+	config        config.Config
+	clientFactory client.Factory
 }
 
 func (s SFTPCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- up
 }
 
 func (s SFTPCollector) Collect(ch chan<- prometheus.Metric) {
-	sftpClient, err := client.NewSFTPClient(s.config)
+	sftpClient, err := s.clientFactory.SFTPClient()
 	if err != nil {
 		ch <- prometheus.MustNewConstMetric(up, prometheus.GaugeValue, 0)
 		log.WithFields(log.Fields{"event": "creating SFTP sftpClient"}).Error(err)
@@ -59,6 +60,9 @@ func (s SFTPCollector) Collect(ch chan<- prometheus.Metric) {
 	ch <- prometheus.MustNewConstMetric(fsFreeSpace, prometheus.GaugeValue, fsStat.FreeSpace)
 }
 
-func NewSFTPCollector(cfg config.Config) prometheus.Collector {
-	return SFTPCollector{cfg}
+func NewSFTPCollector(cfg config.Config, f client.Factory) prometheus.Collector {
+	return SFTPCollector{
+		config:        cfg,
+		clientFactory: f,
+	}
 }
diff --git a/pkg/server/server.go b/pkg/server/server.go
@@ -2,6 +2,7 @@ package server
 
 import (
 	"fmt"
+	"github.com/arunvelsriram/sftp-exporter/pkg/client"
 	"github.com/arunvelsriram/sftp-exporter/pkg/collector"
 	"github.com/arunvelsriram/sftp-exporter/pkg/config"
 	"github.com/prometheus/client_golang/prometheus"
@@ -11,7 +12,8 @@ import (
 )
 
 func Start(cfg config.Config) error {
-	sftpCollector := collector.NewSFTPCollector(cfg)
+	clientFactory := client.NewFactory(cfg)
+	sftpCollector := collector.NewSFTPCollector(cfg, clientFactory)
 	prometheus.MustRegister(sftpCollector)
 
 	r := http.NewServeMux()
@@ -28,4 +30,4 @@ func healthzHandler() http.Handler {
 		_, _ = fmt.Fprintf(w, "healthy")
 	}
 	return http.HandlerFunc(fn)
-}
+}