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|
package objectpool
import (
"bufio"
"bytes"
"context"
"fmt"
"io/ioutil"
"os/exec"
"path/filepath"
"strconv"
"strings"
"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
"github.com/sirupsen/logrus"
"gitlab.com/gitlab-org/gitaly/internal/command"
"gitlab.com/gitlab-org/gitaly/internal/git"
"gitlab.com/gitlab-org/gitaly/internal/git/housekeeping"
"gitlab.com/gitlab-org/gitaly/internal/git/repository"
"gitlab.com/gitlab-org/gitaly/internal/git/updateref"
"gitlab.com/gitlab-org/gitaly/internal/helper"
"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
)
const (
sourceRemote = "origin"
sourceRefNamespace = "refs/remotes/" + sourceRemote
)
// FetchFromOrigin initializes the pool and fetches the objects from its origin repository
func (o *ObjectPool) FetchFromOrigin(ctx context.Context, origin *gitalypb.Repository) error {
if err := o.Init(ctx); err != nil {
return err
}
originPath, err := o.locator.GetPath(origin)
if err != nil {
return err
}
if err := housekeeping.Perform(ctx, o.poolRepo); err != nil {
return err
}
remote := o.poolRepo.Remote()
remoteExists, err := remote.Exists(ctx, sourceRemote)
if err != nil {
return err
}
if remoteExists {
if err := remote.SetURL(ctx, sourceRemote, originPath, git.SetURLOpts{}); err != nil {
return err
}
} else {
if err := remote.Add(ctx, sourceRemote, originPath, git.RemoteAddOpts{}); err != nil {
return err
}
}
if err := o.logStats(ctx, "before fetch"); err != nil {
return err
}
refSpec := fmt.Sprintf("+refs/*:%s/*", sourceRefNamespace)
var stderr bytes.Buffer
if err := o.poolRepo.ExecAndWait(ctx,
git.SubCmd{
Name: "fetch",
Flags: []git.Option{
git.Flag{Name: "--quiet"},
git.Flag{Name: "--atomic"},
},
Args: []string{sourceRemote, refSpec},
},
git.WithRefTxHook(ctx, o.poolRepo, o.cfg),
git.WithStderr(&stderr),
); err != nil {
return helper.ErrInternalf("fetch into object pool: %w, stderr: %q", err,
stderr.String())
}
if err := o.rescueDanglingObjects(ctx); err != nil {
return err
}
if err := o.logStats(ctx, "after fetch"); err != nil {
return err
}
if err := o.poolRepo.ExecAndWait(ctx, git.SubCmd{
Name: "pack-refs",
Flags: []git.Option{git.Flag{Name: "--all"}},
}); err != nil {
return err
}
return o.repackPool(ctx, o)
}
const danglingObjectNamespace = "refs/dangling/"
// rescueDanglingObjects creates refs for all dangling objects if finds
// with `git fsck`, which converts those objects from "dangling" to
// "not-dangling". This guards against any object ever being deleted from
// a pool repository. This is a defense in depth against accidental use
// of `git prune`, which could remove Git objects that a pool member
// relies on. There is currently no way for us to reliably determine if
// an object is still used anywhere, so the only safe thing to do is to
// assume that every object _is_ used.
func (o *ObjectPool) rescueDanglingObjects(ctx context.Context) error {
fsck, err := o.poolRepo.Exec(ctx, git.SubCmd{
Name: "fsck",
Flags: []git.Option{git.Flag{Name: "--connectivity-only"}, git.Flag{Name: "--dangling"}},
})
if err != nil {
return err
}
updater, err := updateref.New(ctx, o.cfg, o.poolRepo, updateref.WithDisabledTransactions())
if err != nil {
return err
}
scanner := bufio.NewScanner(fsck)
for scanner.Scan() {
split := strings.SplitN(scanner.Text(), " ", 3)
if len(split) != 3 {
continue
}
if split[0] != "dangling" {
continue
}
ref := git.ReferenceName(danglingObjectNamespace + split[2])
if err := updater.Create(ref, split[2]); err != nil {
return err
}
}
if err := scanner.Err(); err != nil {
return err
}
if err := fsck.Wait(); err != nil {
return fmt.Errorf("git fsck: %v", err)
}
return updater.Wait()
}
func (o *ObjectPool) repackPool(ctx context.Context, pool repository.GitRepo) error {
config := []git.ConfigPair{
{Key: "pack.island", Value: sourceRefNamespace + "/he(a)ds"},
{Key: "pack.island", Value: sourceRefNamespace + "/t(a)gs"},
{Key: "pack.islandCore", Value: "a"},
{Key: "pack.writeBitmapHashCache", Value: "true"},
}
if err := o.poolRepo.ExecAndWait(ctx, git.SubCmd{
Name: "repack",
Flags: []git.Option{git.Flag{Name: "-aidb"}},
}, git.WithConfig(config...)); err != nil {
return err
}
return nil
}
func (o *ObjectPool) logStats(ctx context.Context, when string) error {
fields := logrus.Fields{
"when": when,
}
for key, dir := range map[string]string{
"poolObjectsSize": "objects",
"poolRefsSize": "refs",
} {
var err error
fields[key], err = sizeDir(ctx, filepath.Join(o.FullPath(), dir))
if err != nil {
return err
}
}
forEachRef, err := o.poolRepo.Exec(ctx, git.SubCmd{
Name: "for-each-ref",
Flags: []git.Option{git.Flag{Name: "--format=%(objecttype)%00%(refname)"}},
Args: []string{"refs/"},
})
if err != nil {
return err
}
danglingRefsByType := make(map[string]int)
normalRefsByType := make(map[string]int)
scanner := bufio.NewScanner(forEachRef)
for scanner.Scan() {
line := bytes.SplitN(scanner.Bytes(), []byte{0}, 2)
if len(line) != 2 {
continue
}
objectType := string(line[0])
refname := string(line[1])
if strings.HasPrefix(refname, danglingObjectNamespace) {
danglingRefsByType[objectType]++
} else {
normalRefsByType[objectType]++
}
}
if err := scanner.Err(); err != nil {
return err
}
if err := forEachRef.Wait(); err != nil {
return err
}
for _, key := range []string{"blob", "commit", "tag", "tree"} {
fields["dangling."+key+".ref"] = danglingRefsByType[key]
fields["normal."+key+".ref"] = normalRefsByType[key]
}
ctxlogrus.Extract(ctx).WithFields(fields).Info("pool dangling ref stats")
return nil
}
func sizeDir(ctx context.Context, dir string) (int64, error) {
// du -k reports size in KB
cmd, err := command.New(ctx, exec.Command("du", "-sk", dir), nil, nil, nil)
if err != nil {
return 0, err
}
sizeLine, err := ioutil.ReadAll(cmd)
if err != nil {
return 0, err
}
if err := cmd.Wait(); err != nil {
return 0, err
}
sizeParts := bytes.Split(sizeLine, []byte("\t"))
if len(sizeParts) != 2 {
return 0, fmt.Errorf("malformed du output: %q", sizeLine)
}
size, err := strconv.ParseInt(string(sizeParts[0]), 10, 0)
if err != nil {
return 0, err
}
// Convert KB to B
return size * 1024, nil
}
|