clonepack/internal/clone/apt/scanner.go
GnomeZworc c4776d81dd
add apt gestion
Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>
2026-04-25 19:03:26 +02:00

145 lines
3.9 KiB
Go

package apt
import (
"compress/gzip"
"context"
"fmt"
"io"
"net/http"
"os"
"path/filepath"
"strings"
"time"
)
// NewPackage is a package present upstream but absent from the local mirror.
type NewPackage struct {
Package string
Version string
Architecture string
Filename string // relative path, e.g. pool/main/c/curl/curl_7.88_amd64.deb
SHA256 string
Size int64
Component string
}
// Scanner compares an upstream APT repository against a local mirror and
// returns packages that are present upstream but missing on disk.
type Scanner struct {
SourceURL string
LocalDir string
Config Config
HTTPClient *http.Client
}
// NewScanner creates a Scanner with a 5-minute HTTP timeout.
func NewScanner(sourceURL, localDir string, cfg Config) *Scanner {
return &Scanner{
SourceURL: strings.TrimRight(sourceURL, "/"),
LocalDir: localDir,
Config: cfg,
HTTPClient: &http.Client{Timeout: 5 * time.Minute},
}
}
// Scan fetches the upstream package lists and returns packages not on disk.
func (sc *Scanner) Scan(ctx context.Context) ([]NewPackage, error) {
suite := sc.Config.Suite
// 1. Fetch InRelease.
inReleaseURL := sc.SourceURL + "/dists/" + suite + "/InRelease"
inReleaseData, err := fetchBytes(ctx, sc.HTTPClient, inReleaseURL)
if err != nil {
return nil, fmt.Errorf("fetch InRelease: %w", err)
}
rf, err := ParseRelease(inReleaseData)
if err != nil {
return nil, fmt.Errorf("parse InRelease: %w", err)
}
// 2 & 3. Fetch Packages.gz for each component/arch, save it, then filter.
var missing []NewPackage
for _, component := range sc.Config.Components {
for _, arch := range sc.Config.Architectures {
if err := ctx.Err(); err != nil {
return nil, err
}
pkgs, err := sc.fetchAndSavePackages(ctx, suite, component, arch, rf)
if err != nil {
return nil, fmt.Errorf("fetch packages for %s/%s: %w", component, arch, err)
}
// 4. Filter: only return packages whose Filename is NOT on disk.
checker := diskPresenceChecker(sc.LocalDir)
for _, pkg := range pkgs {
if !checker(pkg.Filename) {
missing = append(missing, NewPackage{
Package: pkg.Package,
Version: pkg.Version,
Architecture: pkg.Architecture,
Filename: pkg.Filename,
SHA256: pkg.SHA256,
Size: pkg.Size,
Component: component,
})
}
}
}
}
return missing, nil
}
// fetchAndSavePackages fetches Packages.gz for a component/arch, saves it as
// .upstream-Packages.gz (so RegenerateMetadata can use it), and returns parsed packages.
func (sc *Scanner) fetchAndSavePackages(ctx context.Context, suite, component, arch string, rf *ReleaseFile) ([]DebPackage, error) {
wantPath := component + "/binary-" + arch + "/Packages.gz"
// Check that this path is listed in the upstream SHA256 section.
var found bool
for _, e := range rf.SHA256 {
if e.Path == wantPath {
found = true
break
}
}
if !found {
return nil, nil
}
pkgGzURL := sc.SourceURL + "/dists/" + suite + "/" + wantPath
data, err := fetchBytes(ctx, sc.HTTPClient, pkgGzURL)
if err != nil {
return nil, fmt.Errorf("fetch %s: %w", pkgGzURL, err)
}
// Save as .upstream-Packages.gz.
destDir := filepath.Join(sc.LocalDir, "dists", suite, component, "binary-"+arch)
if err := os.MkdirAll(destDir, 0o755); err != nil {
return nil, err
}
upstreamPath := filepath.Join(destDir, upstreamPackagesGz)
if err := atomicWrite(upstreamPath, data); err != nil {
return nil, fmt.Errorf("save %s: %w", upstreamPath, err)
}
// Decompress and parse.
gz, err := gzip.NewReader(strings.NewReader(string(data)))
if err != nil {
return nil, fmt.Errorf("open gzip: %w", err)
}
defer gz.Close()
raw, err := io.ReadAll(gz)
if err != nil {
return nil, fmt.Errorf("decompress: %w", err)
}
pkgs, err := ParsePackages(raw)
if err != nil {
return nil, fmt.Errorf("parse Packages: %w", err)
}
return pkgs, nil
}