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Monorepo for Tangled
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import ( "context" "errors" "fmt" "log/slog" "net" "net/http" "net/url" "strings" "time"
"github.com/mdlayher/vsock")
type UploadCacheBackend interface { http.Handler Close() error}
type UploadCacheProxy struct { port uint32
ln *vsock.Listener server *http.Server backend UploadCacheBackend}
func StartUploadCacheProxy(ctx context.Context, cid uint32, uploadURL string, readUpstreams []CacheUpstream, stagingDir string, logger *slog.Logger) (*UploadCacheProxy, error) { if strings.TrimSpace(uploadURL) == "" { return nil, nil }
if logger == nil { logger = slog.Default() } logger = logger.With("where", "upload_cache_proxy", "cid", cid, "uploadURL", uploadURL)
backend, err := newUploadCacheBackend(uploadURL, readUpstreams, stagingDir, logger) if err != nil { return nil, err }
ln, port, err := listenRandomVsockUploadPort(ctx) if err != nil { return nil, fmt.Errorf("listen for cache upload proxy: %w", err) }
proxy := &UploadCacheProxy{ port: port, ln: ln, backend: backend, } proxy.server = &http.Server{ Handler: backend, Protocols: cacheProxyProtocols(), ReadHeaderTimeout: 30 * time.Second, }
filtered := &cidFilteredVsockListener{ Listener: ln, cid: cid, logger: logger, } go func() { if err := proxy.server.Serve(filtered); err != nil && !errors.Is(err, http.ErrServerClosed) && !errors.Is(err, net.ErrClosed) { logger.Warn("upload cache proxy stopped", "port", port, "error", err) } }()
logger.Info("started upload cache proxy", "port", port, "target", uploadURL, "readUpstreams", len(readUpstreams)) return proxy, nil}
func newUploadCacheBackend(uploadURL string, readUpstreams []CacheUpstream, stagingDir string, logger *slog.Logger) (UploadCacheBackend, error) { if strings.TrimSpace(uploadURL) == "" { return nil, nil }
target, err := url.Parse(uploadURL) if err != nil { return nil, fmt.Errorf("parse upload URL %q: %w", uploadURL, err) }
switch target.Scheme { case "http", "https": if target.Host == "" { return nil, fmt.Errorf("upload URL %q is missing host", uploadURL) } return newHTTPUploadProxyBackend(target, readUpstreams, logger), nil
case "ssh", "ssh-ng": return newNixStoreUploadBackend(target.String(), stagingDir, readUpstreams, logger, nil)
case "": switch uploadURL { case "daemon", "local": return newNixStoreUploadBackend(uploadURL, stagingDir, readUpstreams, logger, nil) default: return nil, fmt.Errorf("unsupported upload URL %q", uploadURL) }
default: return nil, fmt.Errorf("upload URL %q uses unsupported scheme %q", uploadURL, target.Scheme) }}
func (p *UploadCacheProxy) Port() uint32 { if p == nil { return 0 } return p.port}
func (p *UploadCacheProxy) Close() error { if p == nil { return nil }
var closeErr error if p.server != nil { ctx, cancel := context.WithTimeout(context.Background(), time.Second) closeErr = errors.Join(closeErr, p.server.Shutdown(ctx)) cancel() p.server = nil } if p.ln != nil { closeErr = errors.Join(closeErr, p.ln.Close()) p.ln = nil } if p.backend != nil { closeErr = errors.Join(closeErr, p.backend.Close()) } return closeErr}
func listenRandomVsockUploadPort(ctx context.Context) (*vsock.Listener, uint32, error) { var lastErr error for range 32 { port, err := randomVsockPort() if err != nil { return nil, 0, err } ln, err := vsock.Listen(port, nil) if err == nil { return ln, port, nil } lastErr = err
select { case <-ctx.Done(): return nil, 0, ctx.Err() default: } } return nil, 0, fmt.Errorf("listen on random vsock upload port: %w", lastErr)}