Add subscription manager

app/subscription/documentfetcher/httpfetcher/http.go

@@ -0,0 +1,60 @@
+package httpfetcher
+
+import (
+	"context"
+	"io"
+	gonet "net"
+	"net/http"
+
+	"github.com/v2fly/v2ray-core/v5/common"
+	"github.com/v2fly/v2ray-core/v5/common/net"
+
+	"github.com/v2fly/v2ray-core/v5/app/subscription"
+	"github.com/v2fly/v2ray-core/v5/app/subscription/documentfetcher"
+	"github.com/v2fly/v2ray-core/v5/common/environment"
+	"github.com/v2fly/v2ray-core/v5/common/environment/envctx"
+)
+
+//go:generate go run github.com/v2fly/v2ray-core/v5/common/errors/errorgen
+
+func newHTTPFetcher() *httpFetcher {
+	return &httpFetcher{}
+}
+
+func init() {
+	common.Must(documentfetcher.RegisterFetcher("http", newHTTPFetcher()))
+}
+
+type httpFetcher struct{}
+
+func (h *httpFetcher) DownloadDocument(ctx context.Context, source *subscription.ImportSource, opts ...documentfetcher.FetcherOptions) ([]byte, error) {
+	instanceNetwork := envctx.EnvironmentFromContext(ctx).(environment.InstanceNetworkCapabilitySet)
+	outboundDialer := instanceNetwork.OutboundDialer()
+	var httpRoundTripper http.RoundTripper //nolint: gosimple
+	httpRoundTripper = &http.Transport{
+		DialContext: func(ctx_ context.Context, network string, addr string) (gonet.Conn, error) {
+			dest, err := net.ParseDestination(network + ":" + addr)
+			if err != nil {
+				return nil, newError("unable to parse destination")
+			}
+			return outboundDialer(ctx, dest, source.ImportNetworkTag)
+		},
+	}
+	request, err := http.NewRequest("GET", source.Url, nil)
+	if err != nil {
+		return nil, newError("unable to generate request").Base(err)
+	}
+	resp, err := httpRoundTripper.RoundTrip(request)
+	if err != nil {
+		return nil, newError("unable to send request").Base(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, newError("unexpected http status ", resp.StatusCode, "=", resp.Status)
+	}
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, newError("unable to read response").Base(err)
+	}
+	return data, nil
+}