smarthttp: optionally follow info/refs redirects into Endpoint

39e0654→main·

nodo·2mo ago·2 files·+84 added/-0 removed

Adds Conn.FollowInfoRefsRedirect (off by default). When set, RequestInfoRefs rewrites Endpoint.Scheme + Endpoint.Host to the final URL after HTTP redirects, so subsequent PostRPC* calls target the redirected node instead of the originally-configured entry point.

Matches vanilla git's smart-HTTP behaviour for discovery-aware servers that 307 /info/refs to a hosting replica (the entiredb info/refs discovery design). Endpoint.Path is never modified — it still holds the repo path.

Co-Authored-By: Claude Opus 4.7 (1M context) noreply@anthropic.com

Changes

2

• internal/gitproto

• Msmarthttp.go+17

  • Msmarthttp_test.go+67

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Transport transport.Transport
    HTTP      *http.Client
    Auth      transport.AuthMethod

// FollowInfoRefsRedirect, when true, rewrites Endpoint.Scheme and
    // Endpoint.Host to the final URL returned by RequestInfoRefs after
    // HTTP redirects. Subsequent PostRPC* calls then target the
    // redirected host directly, matching vanilla git's smart-HTTP
    // behaviour for discovery-aware servers that 307 /info/refs to a
    // hosting replica. Endpoint.Path is never modified — it still
    // contains the repo path. Off by default to preserve behaviour for
    // callers that rely on Endpoint being stable.
    FollowInfoRefsRedirect bool
}

// NewConn creates a new connection to the given endpoint.
58 unmodified lines

if err := httpError(res); err != nil {
        return nil, err
    }
    if conn.FollowInfoRefsRedirect && res.Request != nil && res.Request.URL != nil {
        final := res.Request.URL
        if final.Host != conn.Endpoint.Host || final.Scheme != conn.Endpoint.Scheme {
            conn.Endpoint.Scheme = final.Scheme
            conn.Endpoint.Host = final.Host
        }
    }
    // Bound the read to prevent unbounded memory allocation (issue #9).
    const maxInfoRefsSize = 64 * 1024 * 1024 // 64 MiB
    lr := io.LimitReader(res.Body, maxInfoRefsSize+1)

Minternal/gitproto/smarthttp.go+17

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"errors"
    "io"
    "net/http"
    "net/http/httptest"
    "strings"
    "testing"
    "time"

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}

// TestRequestInfoRefs_FollowInfoRefsRedirect verifies that when the flag is
// set, a 307 on /info/refs rewrites Conn.Endpoint.Host so subsequent PostRPC
// calls target the redirected node. Matches vanilla git's smart-HTTP
// behaviour and lets clients use a cluster entry domain for info/refs while
// packs land on the hosting replica.
func TestRequestInfoRefs_FollowInfoRefsRedirect(t *testing.T) {
    node := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        w.Header().Set("Content-Type", "application/x-git-upload-pack-advertisement")
        _, _ = w.Write([]byte("001e# service=git-upload-pack\n0000"))
    }))
    defer node.Close()

entry := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        http.Redirect(w, r, node.URL+r.URL.Path+"?"+r.URL.RawQuery, http.StatusTemporaryRedirect)
    }))
    defer entry.Close()

ep, err := transport.NewEndpoint(entry.URL + "/repo.git")
    if err != nil {
        t.Fatalf("parse endpoint: %v", err)
    }
    conn := NewConn(ep, "test", nil, http.DefaultTransport)
    conn.FollowInfoRefsRedirect = true

if _, err := RequestInfoRefs(t.Context(), conn, transport.UploadPackService, ""); err != nil {
        t.Fatalf("RequestInfoRefs: %v", err)
    }

nodeURL := strings.TrimPrefix(node.URL, "http://")
    if conn.Endpoint.Host != nodeURL {
        t.Errorf("Endpoint.Host = %q, want %q (endpoint should follow the 307)", conn.Endpoint.Host, nodeURL)
    }
}

// TestRequestInfoRefs_DoesNotFollowByDefault confirms the default behaviour
// is unchanged: Endpoint is stable even if the server 307s.
func TestRequestInfoRefs_DoesNotFollowByDefault(t *testing.T) {
    node := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        w.Header().Set("Content-Type", "application/x-git-upload-pack-advertisement")
        _, _ = w.Write([]byte("001e# service=git-upload-pack\n0000"))
    }))
    defer node.Close()

ep, err := transport.NewEndpoint(entry.URL + "/repo.git")
    if err != nil {
        t.Fatalf("parse endpoint: %v", err)
    }
    entryHost := ep.Host
    conn := NewConn(ep, "test", nil, http.DefaultTransport)
    // FollowInfoRefsRedirect intentionally not set.

if _, err := RequestInfoRefs(t.Context(), conn, transport.UploadPackService, ""); err != nil {
        t.Fatalf("RequestInfoRefs: %v", err)
    }

if conn.Endpoint.Host != entryHost {
        t.Errorf("Endpoint.Host = %q, want %q (endpoint should be unchanged by default)", conn.Endpoint.Host, entryHost)
    }
}

func TestHTTPErrorBoundsBodyRead(t *testing.T) {
    req, err := http.NewRequestWithContext(t.Context(), http.MethodGet, "https://example.com/repo.git", nil)
    if err != nil {  
          
    }