package pkg import ( "archive/tar" "bufio" "crypto/sha256" "fmt" "io" "io/ioutil" "log" "net/http" "os" "os/exec" "path/filepath" "strings" "github.com/pkg/errors" "mcquay.me/fs" "mcquay.me/pm" "mcquay.me/pm/db" "mcquay.me/pm/keyring" ) const cache = "var/cache/pm" const installed = "var/lib/pm/installed" // Install fetches and installs pkgs from appropriate remotes. func Install(root string, pkgs []string) error { av, err := db.LoadAvailable(root) if err != nil { return errors.Wrap(err, "loading available db") } ms, err := av.Installable(pkgs) if err != nil { return errors.Wrap(err, "checking ability to install") } cacheDir := filepath.Join(root, cache) if !fs.Exists(cacheDir) { if err := os.MkdirAll(cacheDir, 0755); err != nil { return errors.Wrap(err, "creating non-existent cache dir") } } if !fs.IsDir(cacheDir) { return errors.Errorf("%q is not a directory!", cacheDir) } installedDir := filepath.Join(root, installed) if !fs.Exists(installedDir) { if err := os.MkdirAll(installedDir, 0755); err != nil { return errors.Wrap(err, "creating non-existent cache dir") } } if !fs.IsDir(cacheDir) { return errors.Errorf("%q is not a directory!", cacheDir) } if err := download(cacheDir, ms); err != nil { return errors.Wrap(err, "downloading") } for _, m := range ms { log.Printf("%+v", m) if err := verifyManifestIntegrity(root, m); err != nil { return errors.Wrap(err, "verifying pkg integrity") } if err := expandPkgContents(root, m); err != nil { if err := os.RemoveAll(filepath.Join(root, installed, string(m.Name))); err != nil { err = errors.Wrap(err, "cleaning up") } return errors.Wrap(err, "verifying pkg contents") } if err := script(root, m, "pre-install"); err != nil { return errors.Wrap(err, "pre-install") } if err := script(root, m, "post-install"); err != nil { return errors.Wrap(err, "pre-install") } } return errors.New("NYI") } func download(cache string, ms pm.Metas) error { // TODO (sm): concurrently fetch for _, m := range ms { resp, err := http.Get(m.URL()) if err != nil { return errors.Wrap(err, "http get") } fn := filepath.Join(cache, m.Pkg()) f, err := os.Create(fn) if err != nil { return errors.Wrap(err, "creating") } if n, err := io.Copy(f, resp.Body); err != nil { return errors.Wrapf(err, "copy %q to disk after %d bytes", m.URL(), n) } if err := resp.Body.Close(); err != nil { return errors.Wrap(err, "closing resp body") } } return nil } func verifyManifestIntegrity(root string, m pm.Meta) error { pn := filepath.Join(root, cache, m.Pkg()) man, err := getReadCloser(pn, "manifest.sha256") if err != nil { return errors.Wrap(err, "getting manifest reader") } sig, err := getReadCloser(pn, "manifest.sha256.asc") if err != nil { return errors.Wrap(err, "getting manifest reader") } if err := keyring.Verify(root, man, sig); err != nil { return errors.Wrap(err, "verifying manifest") } if err := man.Close(); err != nil { return errors.Wrap(err, "closing manifest reader") } if err := sig.Close(); err != nil { return errors.Wrap(err, "closing manifest signature reader") } return nil } func expandPkgContents(root string, m pm.Meta) error { pn := filepath.Join(root, cache, m.Pkg()) man, err := getReadCloser(pn, "manifest.sha256") if err != nil { return errors.Wrap(err, "getting manifest reader") } ip := filepath.Join(root, installed, string(m.Name)) if err := os.MkdirAll(ip, 0755); err != nil { return errors.Wrapf(err, "making install dir for %q", m.Name) } cs := map[string]string{} s := bufio.NewScanner(man) for s.Scan() { elems := strings.Split(s.Text(), "\t") if len(elems) != 2 { return errors.Errorf("manifest format error; got %d elements, want 2", len(elems)) } cs[elems[1]] = elems[0] } if err := man.Close(); err != nil { return errors.Wrap(err, "closing manifest reader") } if err := s.Err(); err != nil { return errors.Wrap(err, "scanning manifest") } pf, err := os.Open(pn) if err != nil { return errors.Wrap(err, "opening pkg file") } tr := tar.NewReader(pf) for { hdr, err := tr.Next() if err == io.EOF { break } if err != nil { return errors.Wrap(err, "tar traversal") } if hdr.Name == "manifest.sha256" || hdr.Name == "manifest.sha256.asc" { continue } if hdr.FileInfo().IsDir() { if hdr.Name != "bin" { return errors.Errorf("%v is unexpected", hdr.Name) } if err := os.MkdirAll(filepath.Join(ip, hdr.Name), hdr.FileInfo().Mode()); err != nil { return errors.Wrapf(err, "mkdir for %v", hdr.Name) } continue } sha, ok := cs[hdr.Name] if !ok { return errors.Errorf("extra file %q found in tarfile!", hdr.Name) } name := filepath.Join(ip, hdr.Name) sr := sha256.New() var o io.WriteCloser o = close{ioutil.Discard} if hdr.Name != "root.tar.bz2" { f, err := os.OpenFile(filepath.Join(ip, hdr.Name), os.O_WRONLY|os.O_CREATE, hdr.FileInfo().Mode()) if err != nil { return errors.Wrap(err, "open file in install dir") } o = f } w := io.MultiWriter(o, sr) if n, err := io.Copy(w, tr); err != nil { return errors.Wrapf(err, "copying file %q after %v bytes", hdr.Name, n) } if sha != fmt.Sprintf("%x", sr.Sum(nil)) { return errors.Errorf("%q checksum was incorrect", hdr.Name) } if err := o.Close(); err != nil { return errors.Wrapf(err, "closing %v", name) } } return nil } type tarSlurper struct { f *os.File tr *tar.Reader } func (ts *tarSlurper) Close() error { return ts.f.Close() } func (ts *tarSlurper) Read(p []byte) (int, error) { return ts.tr.Read(p) } func getReadCloser(tn, fn string) (io.ReadCloser, error) { pf, err := os.Open(tn) if err != nil { return nil, errors.Wrap(err, "opening pkg file") } tr := tar.NewReader(pf) for { hdr, err := tr.Next() if err == io.EOF { break } if err != nil { return nil, errors.Wrap(err, "tar traversal") } if hdr.Name == fn { return &tarSlurper{pf, tr}, nil } } return nil, errors.Errorf("%q not found", fn) } // close should be used to wrap ioutil.Discard to give it a noop Close method. type close struct { io.Writer } func (close) Close() error { return nil } func script(root string, m pm.Meta, name string) error { bin := filepath.Join(root, installed, string(m.Name), "bin", name) if !fs.Exists(bin) { return nil } cmd := exec.Command(bin) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr return cmd.Run() }