feat: add support for https

cmd/hp_healthcheck/hp_healthcheck.go

@@ -1,18 +1,36 @@
 package main
 
 import (
+	"crypto/tls"
 	"fmt"
 	"net/http"
 	"os"
 	"time"
 )
 
+// hp_healthcheck pings the Headplane /healthz endpoint. It's invoked
+// from the Docker HEALTHCHECK directive, so it must work whether the
+// container is serving plain HTTP or has TLS termination enabled.
+//
+// Configuration (via env, all optional):
+//   - HEADPLANE_HEALTHCHECK_URL   full URL, takes precedence over the
+//     pieces below (default: http://localhost:3000/admin/healthz)
+//   - HEADPLANE_HEALTHCHECK_TLS   "true" to use https://
+//   - HEADPLANE_HEALTHCHECK_HOST  default: localhost
+//   - HEADPLANE_HEALTHCHECK_PORT  default: 3000
+//   - HEADPLANE_HEALTHCHECK_PATH  default: /admin/healthz
 func main() {
+	url := healthcheckURL()
+
 	client := http.Client{
 		Timeout: 5 * time.Second,
+		Transport: &http.Transport{
+			// We just care that the server is alive and with us
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+		},
 	}
 
-	resp, err := client.Get("http://localhost:3000/admin/healthz")
+	resp, err := client.Get(url)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Health check failed: %v\n", err)
 		os.Exit(1)
@@ -27,3 +45,31 @@ func main() {
 	fmt.Println("Health check passed.")
 	os.Exit(0)
 }
+
+func healthcheckURL() string {
+	if v := os.Getenv("HEADPLANE_HEALTHCHECK_URL"); v != "" {
+		return v
+	}
+
+	scheme := "http"
+	if os.Getenv("HEADPLANE_HEALTHCHECK_TLS") == "true" {
+		scheme = "https"
+	}
+
+	host := os.Getenv("HEADPLANE_HEALTHCHECK_HOST")
+	if host == "" {
+		host = "localhost"
+	}
+
+	port := os.Getenv("HEADPLANE_HEALTHCHECK_PORT")
+	if port == "" {
+		port = "3000"
+	}
+
+	path := os.Getenv("HEADPLANE_HEALTHCHECK_PATH")
+	if path == "" {
+		path = "/admin/healthz"
+	}
+
+	return fmt.Sprintf("%s://%s:%s%s", scheme, host, port, path)
+}