The WebTransport proxy path in serveWebTransport duplicated the
dynamic-upstream-fallback block and the {http.reverse_proxy.upstream.*}
replacer-variable block from proxyLoopIteration. Francis flagged this
as a maintenance burden in review of #7669.
Extract two helpers:
* resolveUpstreams(r) returns the candidate upstream set — dynamic
when configured (with provisioning + fallback-on-error), static
otherwise. Caller runs the LB selection policy, since the two call
sites diverge on how selection failure is reported (retry loop vs.
fast 502 for long-lived WT sessions).
* setUpstreamReplacerVars(repl, up, di) publishes the seven
placeholders describing the selected upstream.
Both are used by proxyLoopIteration and serveWebTransport with
identical semantics to the inlined code they replace. No behavior
change for either path.
Extends the http reverse-proxy transport with a webtransport boolean
that opts the upstream into WebTransport passthrough. Must be combined
with versions: ["3"]; WebTransport rides on HTTP/3 exclusively.
When enabled, Handler.ServeHTTP detects Extended CONNECT with
:protocol=webtransport early — before any of the normal round-trip
machinery — and branches to serveWebTransport, which:
1. Pulls the *webtransport.Server off caddyhttp.Server (via
WebTransportServer()) and errors out cleanly if HTTP/3 isn't
enabled on the frontend.
2. Picks a single upstream through the configured load-balancer.
No retries: a failed dial closes the client session and returns.
3. Walks the response-writer Unwrap() chain to reach the raw http3
writer and calls webtransport.Server.Upgrade to terminate the
incoming session.
4. Uses dialUpstreamWebTransport to open a session to the selected
upstream, forwarding request headers on the Extended CONNECT.
5. Runs runWebTransportPump between the two sessions and blocks
until both close.
The transport's wtTLSConfig is built at Provision time from the
existing TLS config (same path h3Transport already uses) and reused
for every session.
Tests: adds TestWebTransport_ReverseProxyEndToEnd which spins up a
single Caddy instance with two HTTP/3 servers — one proxy on :9443,
one terminating echo upstream on :9444 — and drives a real
webtransport.Dialer through the proxy to assert end-to-end
bidirectional-stream echo.
* reverseproxy: Add ability to clear dynamic upstreams cache during retries
This is an optional interface for dynamic upstream modules to implement if they cache results.
TODO: More documentation; this is an experiment.
* Add some godoc
* Export interface; update godoc
This refactors the initial approach in PR #7281, replacing the UsagePool
with a dedicated package-level sync.Map and atomic.Int64 to track
in-flight requests without global lock contention.
It also introduces a lookup map in the admin API to fix a potential
O(n^2) iteration over upstreams, ensuring that draining upstreams
are correctly exposed across config reloads without leaking memory.
Co-authored-by: Y.Horie <u5.horie@gmail.com>
reverseproxy: optimize in-flight tracking and admin API
- Replaced sync.RWMutex with sync.Map and atomic.Int64 to avoid lock contention under high RPS.
- Introduced a lookup map in the admin API to fix a potential O(n^2) iteration over upstreams.
When a request arrives via a Unix domain socket (RemoteAddr == "@"),
net.SplitHostPort fails, causing addForwardedHeaders to strip all
X-Forwarded-* headers even when the connection is trusted via
trusted_proxies_unix.
Handle Unix socket connections before parsing RemoteAddr: if untrusted,
strip headers for security; if trusted, let clientIP remain empty (no
peer IP for a Unix socket hop) and fall through to the shared header
logic, preserving the existing XFF chain without appending a spurious
entry.
Amp-Thread-ID: https://ampcode.com/threads/T-019c4225-a0ad-7283-ac56-e2c01eae1103
Co-authored-by: Amp <amp@ampcode.com>
* capture the buffered body once, then reset clonedReq.Body before each retry
* no copy
* keep receiver name
* set the buf to nil after extraction and only return it to pool if not nil
---------
Co-authored-by: WeidiDeng <weidi_deng@icloud.com>
* chore: upgrade .golangci.yml and workflow to v2
run `golangci-lint fmt`
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* run `golangci-lint run --fix`
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* more lint fixes
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* bring back comments to .golangci.yml
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* appease the linter some more
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* oops
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* use embedded structs
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* use embedded structs where they were used before
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* disable rule `-QF1006`
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* missed a spot
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
---------
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
Currently if we extract the DialInfo from a Request Context during an active health check, then the Upstream in the DialInfo is nil.
This PR attempts to set the Upstream to a sensible value, based on wether or not the Upstream has been overriden in the active health check's config.
* reverse_proxy: re-add healthy upstreams metric
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* lint
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
---------
Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* buffer requests for fastcgi by default
* fix import cycle
* fix the return value of bufferedBody
* more comments about fastcgi buffering
---------
Co-authored-by: Matt Holt <mholt@users.noreply.github.com>
* reverse proxy: rewrite requests and responses for websocket over http2
* delete protocol pseudo-header
* modify cloned requests
* set request variable to track if it's a h2 websocket
* use request bodu
* rewrite request body
* use WebSocket instead of Websocket in the headers
* use logger check for zap loggers
* fix lint
i.e. Revert commit f5dce84a70
Two years ago, the patch in #4952 was a seemingly necessary way to fix an issue (sort of an edge case), but it broke other more common use cases (see #6666).
Now, as of #6669, it seems like the original issue can no longer be replicated, so we are reverting that patch, because it was incorrect anyway.
If it turns out the original issue returns, a more proper patch may be in #6669 (even if used as a baseline for a future fix). A potential future fix could be an opt-in setting.
* caddyhttp: Add `MatchWithError` to replace SetVar hack
* Error in IP matchers on TLS handshake not complete
* Use MatchWithError everywhere possible
* Move implementations to MatchWithError versions
* Looser interface checking to allow fallback
* CEL factories can return RequestMatcherWithError
* Clarifying comment since it's subtle that an err is returned
* Return 425 Too Early status in IP matchers
* Keep AnyMatch signature the same for now
* Apparently Deprecated can't be all-uppercase to get IDE linting
* Linter
Most of the errors that can be seen here are write errors due to clients
aborting the request from their side. Often seen ones include:
* writing: ... write: broken pipe
* writing: ... connection timed out
* writing: http2: stream closed
* writing: timeout...
* writing: h3 error...
Most of these errors are beyond of the control of caddy on the client side,
probably nothing can be done on the server side. It still warrants
researching when these errors occur very often, so a change in level from
error to warn is better here to not polute the logs with errors in the
normal case.
* caddyhttp: Reject 0-RTT early data in IP matchers and set Early-Data header when proxying
See RFC 8470: https://httpwg.org/specs/rfc8470.html
Thanks to Michael Wedl (@MWedl) at the University of Applied Sciences St. Poelten for reporting this.
* Don't return value for {remote} placeholder in early data
* Add Caddyfile support
Before this change, a read of size (let's say) < 10, into a buffer of size 10, will return EOF because we're using CopyN to limit to the size of the buffer. That resulted in the body being read from later, which should only happen if it couldn't fit in the buffer.
With this change, the body is properly NOT set when it can all fit in the buffer.
* reverseproxy: Add more debug logs
This makes debug logging very noisy when reverse proxying, but I guess
that's the point.
This has shown to be useful in troubleshooting infrastructure issues.
* Update modules/caddyhttp/reverseproxy/streaming.go
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* Update modules/caddyhttp/reverseproxy/streaming.go
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* Add opt-in `trace_logs` option
* Rename to VerboseLogs
---------
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
