jeessy2/ddns-go · warning

interface %s not found: %v

Error message

interface %s not found: %v

What it means

Returned by getLocalAddrFromInterfaceByNetwork (util/http_client_util.go:15) when net.InterfaceByName(ifaceName) fails, i.e. the configured network interface name does not exist on this machine. CreateBoundNoProxyHTTPClient calls it to bind an HTTP client to a specific interface; on failure it logs and silently falls back to the default (no-proxy) client, so callers usually only see the log line, not a hard error.

Source

Thrown at util/http_client_util.go:15

package util

import (
	"context"
	"crypto/tls"
	"fmt"
	"net"
	"net/http"
	"time"
)

func getLocalAddrFromInterfaceByNetwork(ifaceName, network string) (string, error) {
	iface, err := net.InterfaceByName(ifaceName)
	if err != nil {
		return "", fmt.Errorf("interface %s not found: %v", ifaceName, err)
	}
	addrs, err := iface.Addrs()
	if err != nil {
		return "", fmt.Errorf("get interface %s addresses failed: %v", ifaceName, err)
	}

	hasGlobalUnicast := false
	for _, addr := range addrs {
		ipNet, ok := addr.(*net.IPNet)
		if !ok || !ipNet.IP.IsGlobalUnicast() {
			continue
		}
		hasGlobalUnicast = true
		if isIPMatchedNetwork(ipNet.IP, network) {
			return ipNet.IP.String(), nil
		}
	}
	if hasGlobalUnicast && (network == "tcp4" || network == "tcp6") {

View on GitHub (pinned to 5874c2e666)

Solutions

1. Check the actual interface name with `ip link` (Linux), `ifconfig` (macOS) or `ipconfig` (Windows) and fix the configured name
2. Remove/clear the interface binding setting to fall back to the default client
3. If in a container, use the container's own interface (usually eth0) instead of the host's
4. Re-check after NIC renames or driver updates on the host

Example fix

// before
client := util.CreateBoundNoProxyHTTPClient("tcp4", "eth0")
// after
// run `ip link` first; if the NIC is enp3s0:
client := util.CreateBoundNoProxyHTTPClient("tcp4", "enp3s0")

// Go: check the interface exists before configuring the binding
ifaceName := "eth0" // value from your config
if _, err := net.InterfaceByName(ifaceName); err != nil {
    log.Printf("interface %q not available, using default client", ifaceName)
    // fall back to util.CreateNoProxyHTTPClient(network)
}

func interfaceExists(name string) bool {
    _, err := net.InterfaceByName(name)
    return err == nil
}

// Go: the library already falls back internally; guard your own binding path
client, err := bindToInterface(cfg.IfaceName, cfg.Network) // wrapper you control
if err != nil {
    log.Printf("binding to %q failed (%v), using default client", cfg.IfaceName, err)
    client = util.CreateNoProxyHTTPClient(cfg.Network)
}

When it happens

Trigger: Calling CreateBoundNoProxyHTTPClient(network, ifaceName) with an interface name that is absent or misspelled (e.g. "eth0" on a system using "enp0s3" or "ens192", or "en0" on Linux); interface removed/renamed after config was written; running in a container that only has eth0 while config references a host NIC.

Common situations: Config copied from another machine; Windows/macOS interface names ("Ethernet", "en0") used on Linux or vice versa; Docker/Kubernetes environments where the host NIC is not visible; NIC renamed by predictable-network-interface-names after a kernel update.

Related errors

• get interface %s addresses failed: %v
• 找不到网卡 %s: %v
• 监听端口发生异常, 请检查端口是否被占用! %s
• 请求 dnsla 失败: %w
• 读取 dnsla 响应失败: %w

AI-assisted analysis of jeessy2/ddns-go@5874c2e666 (2026-09-03). Data as JSON: /api/errors/49caadb96b76507b. Report an issue: GitHub.