Implement reference pruning on push.

Author: chrisgavin

internal/push/push.go

@@ -14,6 +14,8 @@ import (
 "path/filepath"
 "strings"
 
+"github.com/go-git/go-git/v5/plumbing"
+
 "github.com/github/codeql-action-sync/internal/githubapiutil"
 
 log "github.com/sirupsen/logrus"
@@ -22,6 +24,7 @@ import (
 "github.com/github/codeql-action-sync/internal/version"
 "github.com/go-git/go-git/v5"
 "github.com/go-git/go-git/v5/config"
+"github.com/go-git/go-git/v5/plumbing/transport"
 githttp "github.com/go-git/go-git/v5/plumbing/transport/http"
 "github.com/google/go-github/v32/github"
 "github.com/mitchellh/ioprogress"
@@ -142,35 +145,53 @@ func (pushService *pushService) pushGit(repository *github.Repository, initialPu
 }
 
 refSpecBatches := [][]config.RefSpec{}
+remoteReferences, err := remote.List(&git.ListOptions{Auth: credentials})
+if err != nil && err != transport.ErrEmptyRemoteRepository {
+return errors.Wrap(err, "Error listing remote references.")
+}
+deleteRefSpecs := []config.RefSpec{}
+for _, remoteReference := range remoteReferences {
+_, err := gitRepository.Reference(remoteReference.Name(), false)
+if err != nil && err != plumbing.ErrReferenceNotFound {
+return errors.Wrapf(err, "Error finding local reference %s.", remoteReference.Name())
+}
+if err == plumbing.ErrReferenceNotFound {
+deleteRefSpecs = append(deleteRefSpecs, config.RefSpec(":"+remoteReference.Name().String()))
+}
+}
+refSpecBatches = append(refSpecBatches, deleteRefSpecs)
+
 if initialPush {
 releasePathStats, err := ioutil.ReadDir(pushService.cacheDirectory.ReleasesPath())
 if err != nil {
 return errors.Wrap(err, "Error reading releases.")
 }
-refSpecBatches = append(refSpecBatches, []config.RefSpec{})
+initialRefSpecs := []config.RefSpec{}
 for _, releasePathStat := range releasePathStats {
-refSpecBatches[0] = append(refSpecBatches[0], config.RefSpec("+refs/tags/"+releasePathStat.Name()+":refs/tags/"+releasePathStat.Name()))
+initialRefSpecs = append(initialRefSpecs, config.RefSpec("+refs/tags/"+releasePathStat.Name()+":refs/tags/"+releasePathStat.Name()))
 }
+refSpecBatches = append(refSpecBatches, initialRefSpecs)
 } else {
 // We've got to push `main` on its own, so that it will be made the default branch if the repository has just been created. We then push everything else afterwards.
-refSpecBatches = [][]config.RefSpec{
+refSpecBatches = append(refSpecBatches,
 []config.RefSpec{
 config.RefSpec("+refs/heads/main:refs/heads/main"),
 },
 []config.RefSpec{
 config.RefSpec("+refs/*:refs/*"),
 },
-}
+)
 }
 for _, refSpecs := range refSpecBatches {
-err = remote.PushContext(pushService.ctx, &git.PushOptions{
-RefSpecs: refSpecs,
-Auth: credentials,
-Progress: os.Stderr,
-Force: true,
-})
-if err != nil && errors.Cause(err) != git.NoErrAlreadyUpToDate {
-return errors.Wrap(err, "Error pushing Action to GitHub Enterprise Server.")
+if len(refSpecs) != 0 {
+err = remote.PushContext(pushService.ctx, &git.PushOptions{
+RefSpecs: refSpecs,
+Auth: credentials,
+Progress: os.Stderr,
+})
+if err != nil && errors.Cause(err) != git.NoErrAlreadyUpToDate {
+return errors.Wrap(err, "Error pushing Action to GitHub Enterprise Server.")
+}
 }
 }
 

internal/push/push_test.go

@@ -150,6 +150,35 @@ func TestPushGit(t *testing.T) {
 "bd82b85707bc13904e3526517677039d4da4a9bb refs/heads/very-ignored-branch",
 "bd82b85707bc13904e3526517677039d4da4a9bb refs/tags/an-ignored-tag-too",
 "26936381e619a01122ea33993e3cebc474496805 refs/tags/v2",
+"26936381e619a01122ea33993e3cebc474496805 refs/heads/a-ref-that-will-need-pruning",
+})
+
+pushService = getTestPushService(t, "./push_test/action-cache-modified/", "")
+err = pushService.pushGit(&repository, true)
+require.NoError(t, err)
+test.CheckExpectedReferencesInRepository(t, destinationPath, []string{
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/codeql-bundle-20200101",
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/codeql-bundle-20200630",
+"b9f01aa2c50f49898d4c7845a66be8824499fe9d refs/heads/main",
+"26936381e619a01122ea33993e3cebc474496805 refs/heads/v1",
+"e529a54fad10a936308b2220e05f7f00757f8e7c refs/heads/v3",
+"bd82b85707bc13904e3526517677039d4da4a9bb refs/heads/very-ignored-branch",
+"bd82b85707bc13904e3526517677039d4da4a9bb refs/tags/an-ignored-tag-too",
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/v2",
+})
+
+err = pushService.pushGit(&repository, false)
+require.NoError(t, err)
+test.CheckExpectedReferencesInRepository(t, destinationPath, []string{
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/codeql-bundle-20200101",
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/codeql-bundle-20200630",
+"b9f01aa2c50f49898d4c7845a66be8824499fe9d refs/heads/main",
+"26936381e619a01122ea33993e3cebc474496805 refs/heads/v1",
+"e529a54fad10a936308b2220e05f7f00757f8e7c refs/heads/v3",
+"bd82b85707bc13904e3526517677039d4da4a9bb refs/heads/very-ignored-branch",
+"bd82b85707bc13904e3526517677039d4da4a9bb refs/tags/an-ignored-tag-too",
+"26936381e619a01122ea33993e3cebc474496805 refs/tags/v2",
+"26936381e619a01122ea33993e3cebc474496805 refs/heads/a-ref-that-will-need-pruning/because-it-now-has-this-extra-bit",
 })
 }
 

internal/push/push_test/action-cache-initial/git/packed-refs

@@ -1,4 +1,5 @@
 # pack-refs with: peeled fully-peeled sorted 
+26936381e619a01122ea33993e3cebc474496805 refs/heads/a-ref-that-will-need-pruning
 b9f01aa2c50f49898d4c7845a66be8824499fe9d refs/heads/main
 26936381e619a01122ea33993e3cebc474496805 refs/heads/v1
 e529a54fad10a936308b2220e05f7f00757f8e7c refs/heads/v3

internal/push/push_test/action-cache-modified/git/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

internal/push/push_test/action-cache-modified/git/config

@@ -0,0 +1,4 @@
+[core]
+repositoryformatversion = 0
+filemode = true
+bare = true