Basic proxy interaction with downloader

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

Author: afbjorklund

Diff for: pkg/hostagent/proxy/proxy.go

@@ -4,13 +4,19 @@ package proxy
 
 import (
 	"bufio"
+	"bytes"
 	"context"
+	"io"
 	"net"
 	"net/http"
+	"os"
+	"path/filepath"
 	"regexp"
 	"strconv"
 	"time"
 
+	"github.com/lima-vm/lima/pkg/downloader"
+
 	"github.com/elazarl/goproxy"
 	"github.com/sirupsen/logrus"
 )
@@ -47,11 +53,51 @@ func Start(opts ServerOptions) (*Server, error) {
 	return server, nil
 }
 
+func sendFile(req *http.Request, path string) (*http.Response, error) {
+	resp := &http.Response{}
+	resp.Request = req
+	resp.TransferEncoding = req.TransferEncoding
+	resp.Header = make(http.Header)
+	status := http.StatusOK
+	resp.StatusCode = status
+	resp.Status = http.StatusText(status)
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	resp.Body = io.NopCloser(bytes.NewBuffer(b))
+	resp.Header.Set("Content-Type", "application/octet-stream")
+	//resp.Header.Set("Last-Modified", ")
+	resp.ContentLength = int64(len(b))
+	return resp, nil
+}
+
 func listenAndServe(opts ServerOptions) (*http.Server, error) {
+	ucd, err := os.UserCacheDir()
+	if err != nil {
+		return nil, err
+	}
+	cacheDir := filepath.Join(ucd, "lima")
+	downloader.HideProgress = true
+
 	addr := net.JoinHostPort(opts.Address, strconv.Itoa(opts.TCPPort))
 	proxy := goproxy.NewProxyHttpServer()
 	proxy.OnRequest(goproxy.ReqHostMatches(regexp.MustCompile("^.*$"))).
 		HandleConnect(goproxy.AlwaysMitm)
+	proxy.OnRequest().DoFunc(func(req *http.Request, ctx *goproxy.ProxyCtx) (*http.Request, *http.Response) {
+		url := req.URL.String()
+		if res, err := downloader.Cached(url, downloader.WithCacheDir(cacheDir)); err == nil {
+			if resp, err := sendFile(req, res.CachePath); err == nil {
+				return nil, resp
+			}
+		}
+		if res, err := downloader.Download(context.Background(), "", url, downloader.WithCacheDir(cacheDir)); err == nil {
+			if resp, err := sendFile(req, res.CachePath); err == nil {
+				return nil, resp
+			}
+		}
+		return req, nil
+	})
 	proxy.OnRequest(goproxy.ReqHostMatches(regexp.MustCompile("^.*:80$"))).
 		HijackConnect(func(req *http.Request, client net.Conn, ctx *goproxy.ProxyCtx) {
 			defer func() {
@@ -61,8 +107,6 @@ func listenAndServe(opts ServerOptions) (*http.Server, error) {
 				}
 				client.Close()
 			}()
-			url := req.URL.String()
-			ctx.Logf("URL: %s", url)
 			clientBuf := bufio.NewReadWriter(bufio.NewReader(client), bufio.NewWriter(client))
 			remote, err := net.Dial("tcp", req.URL.Host)
 			if err != nil {