CLI: use global image version field

- Restructure config by removing CSP-specific image references
- Add global image field
- Download image lookup table on create
- Download QEMU image on QEMU create

internal/image/raw.go

@@ -0,0 +1,139 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package image
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+
+	"github.com/schollz/progressbar/v3"
+	"github.com/spf13/afero"
+)
+
+// Downloader downloads raw images.
+type Downloader struct {
+	httpc httpc
+	fs    *afero.Afero
+}
+
+// NewDownloader creates a new Downloader.
+func NewDownloader() *Downloader {
+	return &Downloader{
+		httpc: http.DefaultClient,
+		fs:    &afero.Afero{Fs: afero.NewOsFs()},
+	}
+}
+
+// Download downloads the raw image from source.
+func (d *Downloader) Download(ctx context.Context, errWriter io.Writer, showBar bool, source, version string) (string, error) {
+	url, err := url.Parse(source)
+	if err != nil {
+		return "", fmt.Errorf("parsing image source URL: %w", err)
+	}
+	version = filepath.Base(version)
+	var partfile, destination string
+	switch url.Scheme {
+	case "http", "https":
+		cwd, err := os.Getwd()
+		if err != nil {
+			return "", fmt.Errorf("getting current working directory: %w", err)
+		}
+		partfile = filepath.Join(cwd, version+".raw.part")
+		destination = filepath.Join(cwd, version+".raw")
+	case "file":
+		return url.Path, nil
+	default:
+		return "", fmt.Errorf("unsupported image source URL scheme: %s", url.Scheme)
+	}
+	if !d.shouldDownload(destination) {
+		return destination, nil
+	}
+	if err := d.downloadWithProgress(ctx, errWriter, showBar, source, partfile); err != nil {
+		return "", err
+	}
+	return destination, d.fs.Rename(partfile, destination)
+}
+
+// shouldDownload checks if the image should be downloaded.
+func (d *Downloader) shouldDownload(destination string) bool {
+	_, err := d.fs.Stat(destination)
+	return errors.Is(err, fs.ErrNotExist)
+}
+
+// downloadWithProgress downloads the raw image from source to the destination.
+func (d *Downloader) downloadWithProgress(ctx context.Context, errWriter io.Writer, showBar bool, source, destination string) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, source, nil)
+	if err != nil {
+		return fmt.Errorf("creating request: %w", err)
+	}
+
+	resp, err := d.httpc.Do(req)
+	if err != nil {
+		return fmt.Errorf("doing request: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("downloading from %q: %s", source, resp.Status)
+	}
+
+	f, err := d.fs.OpenFile(destination, os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	var bar io.WriteCloser
+	if showBar {
+		bar = prepareBar(errWriter, resp.ContentLength)
+	} else {
+		bar = &nopWriteCloser{}
+	}
+	defer bar.Close()
+
+	_, err = io.Copy(io.MultiWriter(f, bar), resp.Body)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func prepareBar(writer io.Writer, total int64) io.WriteCloser {
+	return progressbar.NewOptions64(
+		total,
+		progressbar.OptionSetWriter(writer),
+		progressbar.OptionShowBytes(true),
+		progressbar.OptionSetPredictTime(true),
+		progressbar.OptionFullWidth(),
+		progressbar.OptionSetTheme(progressbar.Theme{
+			Saucer:        "=",
+			SaucerHead:    ">",
+			SaucerPadding: " ",
+			BarStart:      "[",
+			BarEnd:        "]",
+		}),
+		progressbar.OptionClearOnFinish(),
+		progressbar.OptionOnCompletion(func() { fmt.Fprintf(writer, "Done.\n\n") }),
+	)
+}
+
+type nopWriteCloser struct{}
+
+func (*nopWriteCloser) Write(p []byte) (int, error) {
+	return len(p), nil
+}
+
+func (*nopWriteCloser) Close() error {
+	return nil
+}