From 6c264e7a9758dcd19ff1eb34cb91c1729a94e961 Mon Sep 17 00:00:00 2001
From: Ulric Qin <ulric.qin@gmail.com>
Date: Sun, 15 Oct 2023 13:52:30 +0800
Subject: [PATCH] add tcpx.WaitHosts

---
 net/tcpx/tcpx.go | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 net/tcpx/tcpx.go

diff --git a/net/tcpx/tcpx.go b/net/tcpx/tcpx.go
new file mode 100644
index 0000000..2b76126
--- /dev/null
+++ b/net/tcpx/tcpx.go
@@ -0,0 +1,38 @@
+package tcpx
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strings"
+	"time"
+)
+
+func WaitHosts() {
+	hosts := os.Getenv("WAIT_HOSTS")
+	if len(hosts) == 0 {
+		return
+	}
+
+	hosts = strings.ReplaceAll(hosts, ",", " ")
+	array := strings.Fields(hosts)
+
+	for _, host := range array {
+		waitHost(host)
+	}
+}
+
+func waitHost(host string) {
+	for {
+		fmt.Printf("[%s] Waiting for host: %s\n", time.Now(), host)
+
+		conn, err := net.DialTimeout("tcp", host, time.Second)
+		if err == nil {
+			conn.Close()
+			fmt.Printf("[%s] Host is ready: %s\n", time.Now(), host)
+			return
+		}
+
+		time.Sleep(time.Second)
+	}
+}