Add main.go

main.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"bytes"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"html/template"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+)
+
+type K8sList struct {
+	Items []json.RawMessage `json:"items"`
+}
+
+func getEnv(key, fallback string) string {
+	if val, exists := os.LookupEnv(key); exists && val != "" {
+		return val
+	}
+	return fallback
+}
+
+func getTemplate(path string) (*template.Template, error) {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return template.New("haproxy").Parse(string(content))
+}
+
+func getK8sResources(k8sHost, token string, verifySSL bool, resource string) ([]json.RawMessage, error) {
+	url := fmt.Sprintf("%s/api/v1/%s", k8sHost, resource)
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Accept", "application/json")
+
+	client := &http.Client{}
+	if !verifySSL {
+		tr := &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+		}
+		client.Transport = tr
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("HTTP %d: %s", resp.StatusCode, string(body))
+	}
+
+	var list K8sList
+	if err := json.NewDecoder(resp.Body).Decode(&list); err != nil {
+		return nil, err
+	}
+	return list.Items, nil
+}
+
+func main() {
+	k8sHost := getEnv("KUBERNETES_HOST", "")
+	k8sToken := getEnv("KUBERNETES_TOKEN", "")
+	verifySSLStr := getEnv("KUBERNETES_VERIFYSSL", "false")
+	templatePath := getEnv("HAPROXY_TEMPLATE", "haproxy.tmpl")
+
+	if k8sHost == "" || k8sToken == "" {
+		log.Fatal("KUBERNETES_HOST and KUBERNETES_TOKEN must be set")
+	}
+
+	verifySSL, err := strconv.ParseBool(verifySSLStr)
+	if err != nil {
+		log.Fatalf("Invalid KUBERNETES_VERIFYSSL value: %v", err)
+	}
+
+	services, err := getK8sResources(k8sHost, k8sToken, verifySSL, "services")
+	if err != nil {
+		log.Fatalf("Failed to get services: %v", err)
+	}
+	endpoints, err := getK8sResources(k8sHost, k8sToken, verifySSL, "endpoints")
+	if err != nil {
+		log.Fatalf("Failed to get endpoints: %v", err)
+	}
+
+	tmplAbsPath, _ := filepath.Abs(templatePath)
+	tmpl, err := getTemplate(tmplAbsPath)
+	if err != nil {
+		log.Fatalf("Failed to parse template: %v", err)
+	}
+
+	var buf bytes.Buffer
+	err = tmpl.Execute(&buf, map[string]interface{}{
+		"services":  services,
+		"endpoints": endpoints,
+	})
+	if err != nil {
+		log.Fatalf("Failed to render template: %v", err)
+	}
+
+	fmt.Println(buf.String())
+}