git-lfs/commands/command_pre_push.go
brian m. carlson 92e7a27137
pre-push: find named remote for URL if possible
Some users use tools like JGit, which use URLs instead of named remotes
when invoking the pre-push hook.  This is problematic because we use
remote-tracking branches to optimize our ref walk and when a user is
using a URL, we can't apply that optimization since we don't know which
named remote is being used.

However, if we have a named remote with only one URL, we can apply this
optimization by looking up the remote name and using that as our remote
instead.  We do this only in the pre-push hook, since this is the major
time that we need to walk the history.

Add some unit and integration tests for this and also update one of the
existing integration tests which was relying on the previous behavior by
switching it to use an equivalent URL instead of the actual remote URL.
2020-05-04 17:13:19 +00:00

111 lines
3.0 KiB
Go

package commands
import (
"bufio"
"io"
"os"
"strings"
"github.com/git-lfs/git-lfs/git"
"github.com/rubyist/tracerx"
"github.com/spf13/cobra"
)
var (
prePushDryRun = false
prePushDeleteBranch = strings.Repeat("0", 40)
)
// prePushCommand is run through Git's pre-push hook. The pre-push hook passes
// two arguments on the command line:
//
// 1. Name of the remote to which the push is being done
// 2. URL to which the push is being done
//
// The hook receives commit information on stdin in the form:
// <local ref> <local sha1> <remote ref> <remote sha1>
//
// In the typical case, prePushCommand will get a list of git objects being
// pushed by using the following:
//
// git rev-list --objects <local sha1> ^<remote sha1>
//
// If any of those git objects are associated with Git LFS objects, those
// objects will be pushed to the Git LFS API.
//
// In the case of pushing a new branch, the list of git objects will be all of
// the git objects in this branch.
//
// In the case of deleting a branch, no attempts to push Git LFS objects will be
// made.
func prePushCommand(cmd *cobra.Command, args []string) {
if len(args) == 0 {
Print("This should be run through Git's pre-push hook. Run `git lfs update` to install it.")
os.Exit(1)
}
requireGitVersion()
// Remote is first arg
remote, _ := git.MapRemoteURL(args[0], true)
if err := cfg.SetValidPushRemote(remote); err != nil {
Exit("Invalid remote name %q: %s", args[0], err)
}
ctx := newUploadContext(prePushDryRun)
updates := prePushRefs(os.Stdin)
if err := uploadForRefUpdates(ctx, updates, false); err != nil {
ExitWithError(err)
}
}
// prePushRefs parses commit information that the pre-push git hook receives:
//
// <local ref> <local sha1> <remote ref> <remote sha1>
//
// Each line describes a proposed update of the remote ref at the remote sha to
// the local sha. Multiple updates can be received on multiple lines (such as
// from 'git push --all'). These updates are typically received over STDIN.
func prePushRefs(r io.Reader) []*git.RefUpdate {
scanner := bufio.NewScanner(r)
refs := make([]*git.RefUpdate, 0, 1)
// We can be passed multiple lines of refs
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
if len(line) == 0 {
continue
}
tracerx.Printf("pre-push: %s", line)
left, right := decodeRefs(line)
if left.Sha == prePushDeleteBranch {
continue
}
refs = append(refs, git.NewRefUpdate(cfg.Git, cfg.PushRemote(), left, right))
}
return refs
}
// decodeRefs pulls the sha1s out of the line read from the pre-push
// hook's stdin.
func decodeRefs(input string) (*git.Ref, *git.Ref) {
refs := strings.Split(strings.TrimSpace(input), " ")
for len(refs) < 4 {
refs = append(refs, "")
}
leftRef := git.ParseRef(refs[0], refs[1])
rightRef := git.ParseRef(refs[2], refs[3])
return leftRef, rightRef
}
func init() {
RegisterCommand("pre-push", prePushCommand, func(cmd *cobra.Command) {
cmd.Flags().BoolVarP(&prePushDryRun, "dry-run", "d", false, "Do everything except actually send the updates")
})
}