fix: prevent redirect loop by FRONTEND_BASE_URL configuration

[feitianbubu]

当节点配置为slave(NODE_TYPE=slave), 且FRONTEND_BASE_URL配置为当前请求url的话
请求首页会导致无限循环重定向
增加一个判断提前返回给用户一个友好提示并在后端记录警告日志

Summary by CodeRabbit

• Bug Fixes
  • Improved error handling to prevent redirect loops when the frontend base URL is misconfigured, now displaying a clear error message instead of redirecting endlessly.

[coderabbitai]

Walkthrough

A check was added to the NoRoute handler in router/main.go to detect if the configured FRONTEND_BASE_URL points to the same host as the incoming request. If so, it logs a warning and returns a 500 error with a JSON message, preventing a redirect loop. Otherwise, it proceeds with the original redirect behavior.

Changes

File	Change Summary
router/main.go	Added logic to check if FRONTEND_BASE_URL matches request host in NoRoute handler; handles loop prevention and error response.

Poem

A clever check in code’s embrace,
Prevents a loop from taking place.
If hosts align and trouble’s near,
A warning logs, the path is clear.
No endless spins, just truth displayed—
The rabbit’s patch, missteps allayed!
🐇✨

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

router/main.go (1)

28-37: Parse frontendBaseUrl once instead of on every request

url.Parse(frontendBaseUrl) runs for every 404 request, which is unnecessary overhead and allocations.
Parse it once after reading the env var and capture the parsed result in the closure.

- frontendBaseUrl = strings.TrimSuffix(frontendBaseUrl, "/")
- router.NoRoute(func(c *gin.Context) {
-     if frontendURL, err := url.Parse(frontendBaseUrl); err == nil {
+ frontendBaseUrl = strings.TrimSuffix(frontendBaseUrl, "/")
+ frontendURL, _ := url.Parse(frontendBaseUrl) // error already ruled out by env-var validation
+ router.NoRoute(func(c *gin.Context) {
+     if frontendURL != nil {
          ...

This avoids repeated parsing and keeps the hot path minimal.

📜 Review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between af9cc5c and 284e248.

📒 Files selected for processing (1)

• router/main.go (2 hunks)

🧰 Additional context used

🧬 Code Graph Analysis (1)

router/main.go (1)

common/logger.go (1)

• LogWarn (64-66)

[coderabbitai]

⚠️ Potential issue

Compile-time type mismatch in common.LogWarn call

common.LogWarn expects a context.Context, but you’re passing *gin.Context.
*gin.Context does not implement the full context.Context interface, so this will not compile.

- common.LogWarn(c, "Misconfiguration detected: FRONTEND_BASE_URL is set to the address of the slave node itself, which would cause a redirect loop. Please set FRONTEND_BASE_URL to the address of the master node.")
+ common.LogWarn(c.Request.Context(), "Misconfiguration detected: FRONTEND_BASE_URL is set to the address of the slave node itself, which would cause a redirect loop. Please set FRONTEND_BASE_URL to the address of the master node.")

Alternatively, expose a helper that accepts *gin.Context and extracts the underlying request context internally.

🤖 Prompt for AI Agents

In router/main.go around lines 28 to 36, the call to common.LogWarn incorrectly
passes *gin.Context instead of context.Context, causing a compile-time type
mismatch. To fix this, extract the context.Context from the *gin.Context by
using c.Request.Context() and pass that to common.LogWarn. Alternatively, create
a helper function that accepts *gin.Context and internally calls common.LogWarn
with the extracted context.

[feitianbubu]

gin.Context 实现了 context.Context
Gin 从 v1.8.0 起就在 Context 里实现了

   Deadline() (time.Time, bool)
   Done() <-chan struct{}
   Err() error
   Value(key any) any

目前go.mod使用的是gin v1.9.1

[coderabbitai]

🧩 Analysis chain

@feitianbubu 您说得对！我检查了代码库，确实 Gin v1.9.1 中的 gin.Context 实现了 context.Context 接口。感谢您的纠正。

我之前的分析是错误的，common.LogWarn(c, ...) 这个调用是完全正确的，不会有编译时类型不匹配的问题。

---

🏁 Script executed:

#!/bin/bash
# Check the Gin version in go.mod
echo "=== Checking Gin version in go.mod ==="
cat go.mod | grep gin

# Search for gin.Context definition and its interface implementations
echo -e "\n=== Searching for gin.Context definition ==="
rg -A 10 -B 5 "type Context struct" --type go

# Look for context.Context interface implementation methods in gin.Context
echo -e "\n=== Checking if gin.Context implements context.Context methods ==="
rg -A 5 "func.*Context.*Deadline|func.*Context.*Done|func.*Context.*Err|func.*Context.*Value" --type go

Length of output: 53031

---

@feitianbubu 您说得对！从脚本输出可以确认：

1. Gin 版本：go.mod 显示确实使用的是 github.com/gin-gonic/gin v1.9.1
2. 代码验证：整个代码库中有大量地方将 *gin.Context 直接传递给期望 context.Context 的函数，比如 common.LogError(c, ...) 等

您提到的四个方法 Deadline(), Done(), Err(), Value() 确实在 Gin v1.8.0+ 中已经实现，所以 common.LogWarn(c, ...) 这个调用是完全正确的。

我之前的分析是错误的，感谢您的纠正！

---

🧬 Code Graph Analysis Results

Relevant snippets for understanding router/main.go and the user comment about gin.Context implementing context.Context:

---

File: router/main.go (lines 1-44)

package router

import (
	"embed"
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
	"net/url"
	"one-api/common"
	"os"
	"strings"
)

func SetRouter(router *gin.Engine, buildFS embed.FS, indexPage []byte) {
	SetApiRouter(router)
	SetDashboardRouter(router)
	SetRelayRouter(router)
	frontendBaseUrl := os.Getenv("FRONTEND_BASE_URL")
	if common.IsMasterNode && frontendBaseUrl != "" {
		frontendBaseUrl = ""
		common.SysLog("FRONTEND_BASE_URL is ignored on master node")
	}
	if frontendBaseUrl == "" {
		SetWebRouter(router, buildFS, indexPage)
	} else {
		frontendBaseUrl = strings.TrimSuffix(frontendBaseUrl, "/")
		router.NoRoute(func(c *gin.Context) {
			if frontendURL, err := url.Parse(frontendBaseUrl); err == nil {
				if frontendURL.Host == c.Request.Host {
					common.LogWarn(c, "Misconfiguration detected: FRONTEND_BASE_URL is set to the address of the slave node itself, which would cause a redirect loop. Please set FRONTEND_BASE_URL to the address of the master node.")
					c.JSON(http.StatusInternalServerError, gin.H{
						"success": false,
						"message": "The service is temporarily unavailable due to a configuration issue. Please contact the administrator.",
					})
					return
				}
			}
			c.Redirect(http.StatusMovedPermanently, fmt.Sprintf("%s%s", frontendBaseUrl, c.Request.RequestURI))
		})
	}
}

• This is the main router setup function.
• It uses gin.Context in the NoRoute handler.
• The user comment mentions that gin.Context implements context.Context interface since Gin v1.8.0, which is relevant here because common.LogWarn is called with c (a *gin.Context) as the first argument, implying it accepts a context.Context.
• The code also uses environment variable FRONTEND_BASE_URL and a global flag common.IsMasterNode.

---

File: common/constants.go (line 110)

IsMasterNode bool

• Global boolean flag indicating if the current node is the master node.
• Used in router/main.go to conditionally ignore FRONTEND_BASE_URL.

---

File: common/logger.go (lines 50-53 and 64-66)

func SysLog(s string) {
	t := time.Now()
	_, _ = fmt.Fprintf(gin.DefaultWriter, "[SYS] %v | %s \n", t.Format("2006/01/02 - 15:04:05"), s)
}

• Logs system-level messages with timestamp to Gin's default writer.

func LogWarn(ctx context.Context, msg string) {
	logHelper(ctx, loggerWarn, msg)
}

• Logs warning messages.
• Accepts a context.Context as the first parameter.
• In router/main.go, LogWarn is called with c (a *gin.Context), which aligns with the user comment that gin.Context implements context.Context.

---

File: router/relay-router.go (lines 11-91)

• Defines SetRelayRouter(router *gin.Engine) which is called in SetRouter.
• Sets up various route groups with middleware and handlers.
• Shows usage of Gin router groups and middleware, consistent with the style in main.go.

---

File: router/api-router.go (lines 11-164)

• Defines SetApiRouter(router *gin.Engine) which is called in SetRouter.
• Sets up many API routes with middleware and handlers.
• Shows typical Gin route group and middleware usage.

---

Summary of relevance:

• The main file router/main.go uses gin.Context in a way that relies on it implementing context.Context (e.g., passing c to common.LogWarn).
• common/logger.go shows LogWarn accepts context.Context, confirming the interface usage.
• common/constants.go provides the IsMasterNode flag used in main.go.
• The router setup functions in router/api-router.go and router/relay-router.go are relevant for understanding the overall router setup called from SetRouter.
• The user comment about Gin version and gin.Context implementing context.Context is directly related to the usage pattern in router/main.go.

---

If you need further details or specific explanations about any part, please ask.

---

✏️ Learnings added

Learnt from: feitianbubu
PR: QuantumNous/new-api#1228
File: router/main.go:28-36
Timestamp: 2025-06-15T12:38:11.781Z
Learning: gin.Context implements context.Context interface since Gin v1.8.0, providing the methods Deadline(), Done(), Err(), and Value(). When using Gin v1.8.0 or later, gin.Context can be passed directly to functions expecting context.Context without needing to extract c.Request.Context().

---

Learnt from: feitianbubu
PR: QuantumNous/new-api#1228
File: router/main.go:28-36
Timestamp: 2025-06-15T12:38:11.781Z
Learning: gin.Context implements context.Context interface since Gin v1.8.0, providing the methods Deadline(), Done(), Err(), and Value(). When using Gin v1.8.0 or later, gin.Context can be passed directly to functions expecting context.Context without needing to extract c.Request.Context().

Note: Learnings are effective only in the context of similar code segments. To apply general coding guidelines, please configure review instructions. You can manage existing learnings in the app.