Merge pull request #2 from simpledotorg/dhis2-single-metric

Using single metric for dhis2 systems info

.gitignore

@@ -1,2 +1,3 @@
 config.yaml
 .DS_Store
+rtsl_exporter

dhis2/client.go

@@ -1,21 +1,22 @@
 package dhis2
 
 import (
-	"context"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
+	"net"
 	"net/http"
 	"time"
 )
 
-const httpTimeOutSec = 1
+const DefaultConnectionTimeout = 1 * time.Second
 
 type Client struct {
-	Username string
-	Password string
-	BaseURL  string
+	Username          string
+	Password          string
+	BaseURL           string
+	ConnectionTimeout time.Duration
 }
 
 type Info struct {
@@ -38,16 +39,12 @@ func (c *Client) GetInfo() (*Info, error) {
 
 // common method to do request
 func (c *Client) doRequest(path string, result interface{}) error {
-	// Create a context with a timeout
-	ctx, cancel := context.WithTimeout(context.Background(), httpTimeOutSec*time.Second)
-	defer cancel()
-
 	url := fmt.Sprintf("%s%s", c.BaseURL, path)
 
 	// Create a new request
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to create request: %w", err)
 	}
 
 	// Encode credentials
@@ -56,21 +53,38 @@ func (c *Client) doRequest(path string, result interface{}) error {
 	// Set Authorization header
 	req.Header.Set("Authorization", "Basic "+credentials)
 
+	// Custom Transport with Connect Timeout
+	transport := &http.Transport{
+		DialContext: (&net.Dialer{
+			Timeout: c.ConnectionTimeout,
+		}).DialContext,
+	}
+
 	// Make the request
-	client := &http.Client{}
+	client := &http.Client{
+		Transport: transport,
+	}
 	resp, err := client.Do(req)
 	if err != nil {
-		return err
+		return fmt.Errorf("request failed: %w", err)
 	}
 	defer resp.Body.Close()
 
+	// Check if the status code is not 200
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("unexpected status code: %d", resp.StatusCode)
+	}
+
 	// Read the body
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to read response body: %w", err)
 	}
 
 	// Unmarshal JSON response into result
 	err = json.Unmarshal(body, result)
-	return err
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal response: %w", err)
+	}
+	return nil
 }

dhis2/exporter.go

@@ -2,37 +2,22 @@ package dhis2
 
 import (
 	"log"
-	"strings"
+	"sync"
 
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-// sanitizeName prepares a valid prometheus metric name from a given URL
-func sanitizeName(url string) string {
-	// Remove the protocol part
-	cleanURL := strings.TrimPrefix(url, "https://")
-	cleanURL = strings.TrimPrefix(cleanURL, "http://")
-
-	// Replace dots and dashes with underscores
-	cleanURL = strings.ReplaceAll(cleanURL, "-", "_")
-	cleanURL = strings.ReplaceAll(cleanURL, ".", "_")
-
-	return cleanURL
-}
-
 type Exporter struct {
-	client *Client
-
-	info *prometheus.GaugeVec
+	clients []*Client
+	info    *prometheus.GaugeVec
 }
 
-func NewExporter(client *Client) *Exporter {
-	dynamicName := "system_info_" + sanitizeName(client.BaseURL)
+func NewExporter(clients []*Client) *Exporter {
 	return &Exporter{
-		client: client,
+		clients: clients,
 		info: prometheus.NewGaugeVec(prometheus.GaugeOpts{
 			Namespace: "dhis2",
-			Name:      dynamicName,
+			Name:      "system_info",
 			Help:      "Information about the DHIS2 system",
 		}, []string{"version", "revision", "contextPath", "buildTime"}),
 	}
@@ -46,14 +31,25 @@ func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 
 // Collect is called by the Prometheus registry when collecting metrics.
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
-	info, err := e.client.GetInfo()
-	if err != nil {
-		log.Printf("Failed to get dhis2 system information: %v\n", err)
-		return // Early return on error to avoid using uninitialized info
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+
+	for _, client := range e.clients {
+		wg.Add(1)
+		go func(client *Client) {
+			defer wg.Done()
+			info, err := client.GetInfo()
+			if err != nil {
+				log.Printf("ERROR: Failed to get system information from %s: %v\n", client.BaseURL, err)
+				return
+			}
+
+			mu.Lock()
+			e.info.WithLabelValues(info.Version, info.Revision, client.BaseURL, info.BuildTime).Set(1)
+			mu.Unlock()
+		}(client)
 	}
 
-	// Set the version and revision as labels; gauge value is less meaningful here, just set to 1
-	e.info.WithLabelValues(info.Version, info.Revision, info.ContextPath, info.BuildTime).Set(1)
-
+	wg.Wait()
 	e.info.Collect(ch)
 }

main.go

@@ -2,12 +2,13 @@ package main
 
 import (
 	"context"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
 	"os/signal"
-	"io/ioutil"
 	"time"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/simpledotorg/rtsl_exporter/alphasms"
@@ -17,7 +18,7 @@ import (
 )
 
 type Config struct {
-	ALPHASMSAPIKey string `yaml:"alphasms_api_key"`
+	ALPHASMSAPIKey   string `yaml:"alphasms_api_key"`
 	SendGridAccounts []struct {
 		AccountName string `yaml:"account_name"`
 		APIKey      string `yaml:"api_key"`
@@ -73,22 +74,27 @@ func main() {
 		log.Fatalf("Error reading config file: %v", err)
 	}
 
+	// Alphasms
 	if config.ALPHASMSAPIKey == "" {
 		log.Fatalf("ALPHASMS_API_KEY not provided in config file")
 	}
 	alphasmsClient := alphasms.Client{APIKey: config.ALPHASMSAPIKey}
 	alphasmsExporter := alphasms.NewExporter(&alphasmsClient)
 	prometheus.MustRegister(alphasmsExporter)
 
+	// DHIS2
+	dhis2Clients := []*dhis2.Client{}
 	for _, endpoint := range config.DHIS2Endpoints {
 		dhis2Client := dhis2.Client{
-			Username: endpoint.Username,
-			Password: endpoint.Password,
-			BaseURL:  endpoint.BaseURL,
+			Username:          endpoint.Username,
+			Password:          endpoint.Password,
+			BaseURL:           endpoint.BaseURL,
+			ConnectionTimeout: dhis2.DefaultConnectionTimeout,
 		}
-		dhis2Exporter := dhis2.NewExporter(&dhis2Client)
-		prometheus.MustRegister(dhis2Exporter)
+		dhis2Clients = append(dhis2Clients, &dhis2Client)
 	}
+	dhis2Exporter := dhis2.NewExporter(dhis2Clients)
+	prometheus.MustRegister(dhis2Exporter)
 
 	// Register SendGrid exporters
 	apiKeys := make(map[string]string)