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|
package objectpool
import (
"bufio"
"context"
"fmt"
"strings"
grpc_logrus "github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus"
"gitlab.com/gitlab-org/gitaly/internal/command"
"gitlab.com/gitlab-org/gitaly/internal/git"
"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 := helper.GetPath(origin)
if err != nil {
return err
}
getRemotes, err := git.Command(ctx, o, "remote")
if err != nil {
return err
}
remoteReader := bufio.NewScanner(getRemotes)
var originExists bool
for remoteReader.Scan() {
if remoteReader.Text() == sourceRemote {
originExists = true
}
}
if err := getRemotes.Wait(); err != nil {
return err
}
var setOriginCmd *command.Command
if originExists {
setOriginCmd, err = git.Command(ctx, o, "remote", "set-url", sourceRemote, originPath)
if err != nil {
return err
}
} else {
setOriginCmd, err = git.Command(ctx, o, "remote", "add", sourceRemote, originPath)
if err != nil {
return err
}
}
if err := setOriginCmd.Wait(); err != nil {
return err
}
if err := logDanglingRefs(ctx, o, "before fetch"); err != nil {
return err
}
refSpec := fmt.Sprintf("+refs/*:%s/*", sourceRefNamespace)
fetchCmd, err := git.Command(ctx, o, "fetch", "--quiet", sourceRemote, refSpec)
if err != nil {
return err
}
if err := fetchCmd.Wait(); err != nil {
return err
}
if err := rescueDanglingObjects(ctx, o); err != nil {
return err
}
if err := logDanglingRefs(ctx, o, "after fetch"); err != nil {
return err
}
packRefs, err := git.Command(ctx, o, "pack-refs", "--all")
if err != nil {
return err
}
if err := packRefs.Wait(); err != nil {
return err
}
return 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 rescueDanglingObjects(ctx context.Context, repo repository.GitRepo) error {
fsck, err := git.Command(ctx, repo, "fsck", "--connectivity-only", "--dangling")
if err != nil {
return err
}
updater, err := updateref.New(ctx, repo)
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 := 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 repackPool(ctx context.Context, pool repository.GitRepo) error {
repackArgs := []string{
"-c", "pack.island=" + sourceRefNamespace + "/heads",
"-c", "pack.island=" + sourceRefNamespace + "/tags",
"-c", "pack.writeBitmapHashCache=true",
"repack", "-aidb",
}
repackCmd, err := git.Command(ctx, pool, repackArgs...)
if err != nil {
return err
}
if err := repackCmd.Wait(); err != nil {
return err
}
return nil
}
func logDanglingRefs(ctx context.Context, pool repository.GitRepo, when string) error {
forEachRef, err := git.SafeCmd(ctx, pool, nil, git.SubCmd{
Name: "for-each-ref",
Flags: []git.Option{git.Flag{"--format=%(objecttype)"}},
Args: []string{danglingObjectNamespace},
})
if err != nil {
return err
}
counts := make(map[string]int)
scanner := bufio.NewScanner(forEachRef)
for scanner.Scan() {
counts[scanner.Text()]++
}
if err := scanner.Err(); err != nil {
return err
}
if err := forEachRef.Wait(); err != nil {
return err
}
entry := grpc_logrus.Extract(ctx).WithField("when", when)
for _, field := range []string{"blob", "commit", "tag", "tree"} {
key := "dangling." + field + ".ref"
entry = entry.WithField(key, counts[field])
}
entry.Info("pool dangling ref stats")
return nil
}
|
