Files
LocalAI/pkg/downloader/response_header_timeout_test.go
mudler's LocalAI [bot] 16033d562a fix(downloader): bound the wait for response headers so a wedged origin cannot hang an install forever (#11053)
A gallery model install hung for 94 minutes with zero bytes transferred, no
error, no retry and no abort, leaving a partial tree frozen at 18G. The last
log line was the download starting, then silence:

    14:06:19 INFO Downloading url=".../LongCat-Video-Avatar-1.5/resolve/<rev>/base_model/diffusion_pytorch_model-000..."

The retry machinery from #10985 was working (two retries fired at 14:05:01 and
14:06:14); the third attempt simply never returned. The install never
completed, the model config was never written, and nothing surfaced the
failure.

The stall watchdog added earlier wraps the response *body*, so it only starts
guarding once downloadClient.Do() has returned. The transport had no
ResponseHeaderTimeout, so a peer that completes the dial and TLS handshake,
reads the request, and then never sends a status line parks Do() for the
process lifetime. IdleConnTimeout governs pooled idle connections, not an
in-flight request. Both the body request and the HEAD that probes for Range
support were unguarded.

Bound the header wait at the transport, not the client: a client-level Timeout
would also bound the body and truncate multi-tens-of-GB downloads. The knob is
opt-in (WithResponseHeaderTimeout) rather than a default in HardenedTransport,
because a streaming endpoint may legitimately withhold headers until it has
something to say, and capping that would break the streaming clients that share
this constructor.

Also fix a classification trap this exposed: net/http reports a
ResponseHeaderTimeout as an error satisfying errors.Is(err,
context.DeadlineExceeded), which IsRetryable read as "the caller gave up" and
refused to retry. An explicit transient marking now outranks the cancellation
sentinels; a caller who genuinely gave up is still caught by the ctx.Err()
check. The resume probe's error is likewise marked transient, so a momentarily
wedged origin no longer turns a resumable download into a hard install failure.

Third defect found in this download path, after #10985 (read vs write errors
conflated) and #11026 (hash verification emitted no progress and an expired
deadline returned success).


Assisted-by: Claude Code:claude-opus-4-8[1m] [Read] [Edit] [Bash]

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
2026-07-22 18:28:51 +02:00

152 lines
4.7 KiB
Go

package downloader_test
import (
"context"
"net/http"
"net/http/httptest"
"os"
"time"
. "github.com/mudler/LocalAI/pkg/downloader"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
)
var _ = Describe("Download response header timeout", func() {
var filePath string
var savedHeaderTimeout time.Duration
BeforeEach(func() {
dir, err := os.Getwd()
Expect(err).ToNot(HaveOccurred())
filePath = dir + "/respheader_model"
savedHeaderTimeout = DownloadResponseHeaderTimeout
})
AfterEach(func() {
DownloadResponseHeaderTimeout = savedHeaderTimeout
_ = os.Remove(filePath)
_ = os.Remove(filePath + ".partial")
})
It("aborts a request whose response headers never arrive instead of hanging forever", func() {
// The server accepts the connection and reads the request, then never
// writes a status line. The stall watchdog cannot help here: it wraps
// the response body, and there is no response yet. Without a
// ResponseHeaderTimeout on the transport, Do() parks forever and the
// whole install freezes with zero bytes transferred.
release := make(chan struct{})
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
<-release // never write headers
}))
defer server.Close()
defer close(release)
DownloadResponseHeaderTimeout = 300 * time.Millisecond
done := make(chan error, 1)
go func() {
done <- URI(server.URL).DownloadFileWithContext(
context.Background(), filePath, "", 1, 1,
func(s1, s2, s3 string, f float64) {})
}()
var err error
Eventually(done, "5s").Should(Receive(&err))
Expect(err).To(HaveOccurred())
Expect(err.Error()).To(ContainSubstring("timeout awaiting response headers"))
})
It("classifies a response header timeout as retryable so the plan resumes", func() {
release := make(chan struct{})
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
<-release
}))
defer server.Close()
defer close(release)
DownloadResponseHeaderTimeout = 300 * time.Millisecond
done := make(chan error, 1)
go func() {
done <- URI(server.URL).DownloadFileWithContext(
context.Background(), filePath, "", 1, 1,
func(s1, s2, s3 string, f float64) {})
}()
var err error
Eventually(done, "5s").Should(Receive(&err))
Expect(err).To(HaveOccurred())
Expect(IsRetryable(context.Background(), err)).To(BeTrue(),
"a wedged origin must be retried, not treated as a permanent failure")
})
It("aborts a resume probe whose response headers never arrive", func() {
// The HEAD that probes for Range support runs before the body request
// and uses the same client, so it is a second unguarded wait. A
// leftover .partial is what puts that probe on the path.
release := make(chan struct{})
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
<-release
}))
defer server.Close()
defer close(release)
Expect(os.WriteFile(filePath+".partial", make([]byte, 128), 0600)).To(Succeed())
DownloadResponseHeaderTimeout = 300 * time.Millisecond
done := make(chan error, 1)
go func() {
done <- URI(server.URL).DownloadFileWithContext(
context.Background(), filePath, "", 1, 1,
func(s1, s2, s3 string, f float64) {})
}()
var err error
Eventually(done, "5s").Should(Receive(&err))
Expect(err).To(HaveOccurred())
Expect(err.Error()).To(ContainSubstring("timeout awaiting response headers"))
Expect(IsRetryable(context.Background(), err)).To(BeTrue(),
"a wedged resume probe must be retried, not aborted permanently")
})
It("does not bound the body once headers have arrived, so long downloads are not truncated", func() {
// The deliberate "no body deadline" property must survive: headers come
// back promptly, then the body trickles for longer than the header
// timeout. This must succeed.
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if r.Method == "HEAD" {
w.WriteHeader(http.StatusOK)
return
}
w.Header().Set("Content-Length", "4")
w.WriteHeader(http.StatusOK)
for i := 0; i < 4; i++ {
_, _ = w.Write([]byte{byte('a' + i)})
if f, ok := w.(http.Flusher); ok {
f.Flush()
}
time.Sleep(150 * time.Millisecond)
}
}))
defer server.Close()
DownloadResponseHeaderTimeout = 300 * time.Millisecond
done := make(chan error, 1)
go func() {
done <- URI(server.URL).DownloadFileWithContext(
context.Background(), filePath, "", 1, 1,
func(s1, s2, s3 string, f float64) {})
}()
var err error
Eventually(done, "10s").Should(Receive(&err))
Expect(err).ToNot(HaveOccurred())
content, readErr := os.ReadFile(filePath)
Expect(readErr).ToNot(HaveOccurred())
Expect(string(content)).To(Equal("abcd"))
})
})