Implement a simple 'strip prefix' feature for http locations

[cayspekko]

WHY

Though frpproxy isn't meant to be a full blown L7 reverse proxy, this particular feature is useful if you use multiple dynamic paths on the server, but you don't want to hassle with url prefix logic on your http client. Especially useful for http clients that serve pure json apis. In my particular case, I cannot use domain based identifiers. Fit's naturally with the "locations" setting, and thus it only strips those particularly prefixes as they are defined.

Example:

serverAddr = "example.com"
serverPort = 7000

[[proxies]]
name = "fast"
type = "http"
localIP = "127.0.0.1"
localPort = 5000
customDomains = ["example.com"]
locations = ["/example"]
stripPrefix = true

relates to #4981

[kilo-code-bot]

Code Review Summary

Status: 1 Issue Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	1
SUGGESTION	0

Issue Details (click to expand)

WARNING

File	Line	Issue
pkg/util/vhost/http.go	77	Prefix stripping also rewrites paths like /apiv1, so a route registered for /api can unexpectedly forward unrelated requests as /v1.

Other Observations (not in diff)

Issues found in unchanged code that cannot receive inline comments:

File	Line	Issue
pkg/util/vhost/router.go	113	Route matching also uses a raw HasPrefix, so /api currently matches /apiv1; the new strip behavior amplifies that existing ambiguity by rewriting the request path before forwarding.

Files Reviewed (8 files)

• .github/workflows/build-and-push-image.yml - 0 issues
• pkg/config/v1/proxy.go - 0 issues
• pkg/msg/msg.go - 0 issues
• pkg/util/vhost/http.go - 1 issue
• pkg/util/vhost/http_test.go - 0 issues
• pkg/util/vhost/vhost.go - 0 issues
• server/proxy/http.go - 0 issues
• test/e2e/v1/basic/http.go - 0 issues

---

_{Reviewed by gpt-5.4-20260305 · 291,463 tokens}