Improve loading large replays. Fix Docker image build.

Dockerfile

@@ -1,12 +1,13 @@
-FROM golang:1.20-alpine as builder
+FROM golang:1.20 as builder
 WORKDIR /go/pkg/ocap
 COPY . .
 ARG build_commit
-RUN apk add --no-cache alpine-sdk && go build -ldflags "-X github.com/OCAP2/web/server.BuildDate=`date -u +'%Y-%m-%dT%H:%M:%SZ'` -X github.com/OCAP2/web/server.BuildCommit=$build_commit" -a -o app ./cmd
+RUN go build -ldflags "-X github.com/OCAP2/web/server.BuildDate=`date -u +'%Y-%m-%dT%H:%M:%SZ'` -X github.com/OCAP2/web/server.BuildCommit=$build_commit" -a -o app ./cmd
 
-FROM alpine:3.14
+FROM debian:bookworm-slim
 WORKDIR /usr/local/ocap
-RUN mkdir -p /etc/ocap /usr/local/ocap/data /var/lib/ocap/db /var/lib/ocap/maps /var/lib/ocap/data && \
+RUN apt-get update && apt-get install -y ca-certificates && rm -rf /var/lib/apt/lists/* && \
+    mkdir -p /etc/ocap /usr/local/ocap/data /var/lib/ocap/db /var/lib/ocap/maps /var/lib/ocap/data && \
     echo '{}' > /etc/ocap/setting.json
 
 ENV OCAP_MARKERS /usr/local/ocap/markers

cmd/main.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"log"
 	"os"
+	"time"
 
 	"github.com/OCAP2/web/server"
 	"github.com/labstack/echo/v4"
@@ -40,6 +41,11 @@ func app() error {
 
 	e := echo.New()
 
+	// Configure server timeouts for large file transfers
+	// Increased idle timeout to support full-length replay viewing
+	e.Server.ReadTimeout = 0 // No read timeout for large files
+	e.Server.WriteTimeout = 0 // No write timeout for large files
+	e.Server.IdleTimeout = 60 * time.Minute
 	loggerConfig := middleware.DefaultLoggerConfig
 	if setting.Logger {
 		flog, err := os.OpenFile("ocap.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)

server/handler.go

@@ -226,10 +226,26 @@ func (h *Handler) GetCapture(c echo.Context) error {
 
 	upath := filepath.Join(h.setting.Data, filepath.Base(name+".gz"))
 
-	c.Response().Header().Set("Content-Encoding", "gzip")
-	c.Response().Header().Set("Content-Type", "application/json")
+	// Check if file exists
+	fileInfo, statErr := os.Stat(upath)
+	if statErr != nil {
+		return statErr
+	}
 
-	return c.File(upath)
+	// Set appropriate headers for large file transfer with better browser compatibility
+	c.Response().Header().Set("Content-Type", "application/json")
+	c.Response().Header().Set("Content-Encoding", "gzip")
+	c.Response().Header().Set("Content-Length", fmt.Sprintf("%d", fileInfo.Size()))
+	c.Response().Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	c.Response().Header().Set("Pragma", "no-cache")
+	c.Response().Header().Set("Expires", "0")
+	c.Response().Header().Set("Connection", "keep-alive")
+
+	// Remove Transfer-Encoding header to let Go handle it automatically
+	// This can help with browser compatibility issues
+
+	// Use streaming instead of loading entire file into memory
+	return h.streamFile(c, upath)
 }
 
 func (h *Handler) GetCaptureFile(c echo.Context) error {
@@ -321,6 +337,46 @@ func (h *Handler) GetAmmo(c echo.Context) error {
 	return c.File(upath)
 }
 
+func (h *Handler) streamFile(c echo.Context, filepath string) error {
+	// Open the file
+	file, err := os.Open(filepath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// Get file info for Content-Length header
+	fileInfo, err := file.Stat()
+	if err != nil {
+		return err
+	}
+
+	// Set Content-Length header
+	c.Response().Header().Set("Content-Length", fmt.Sprintf("%d", fileInfo.Size()))
+
+	// Stream the file with better buffer control for browser compatibility
+	buffer := make([]byte, 32*1024) // 32KB buffer
+	for {
+		n, err := file.Read(buffer)
+		if err != nil && err != io.EOF {
+			return err
+		}
+		if n == 0 {
+			break
+		}
+
+		// Write to response
+		if _, writeErr := c.Response().Write(buffer[:n]); writeErr != nil {
+			return writeErr
+		}
+
+		// Flush the response to ensure data is sent immediately
+		c.Response().Flush()
+	}
+
+	return nil
+}
+
 func paramPath(c echo.Context, param string) (string, error) {
 	urlPath, err := url.PathUnescape(c.Param(param))
 	if err != nil {