[v0.15] - Adds a temporary fix to avoid race conditions when processing webhooks (#4854)

* [v0.15] - Adds a temporary fix to avoid race conditions when processing webhooks

Looks like after a recent Github API upgrade commits in a ref are updating slower. We're hitting a race condition between the commit received from a webhook and the commit we get from the ref (because in the ref we get sometimes the previous commit - it takes longer to be reflected)

This is a temporary workaround to give time to the ref to be updated.

Refers to: #4853
Signed-off-by: Xavi Garcia <xavi.garcia@suse.com>

* Add context cancelled verification

Signed-off-by: Xavi Garcia <xavi.garcia@suse.com>

---------

Signed-off-by: Xavi Garcia <xavi.garcia@suse.com>

Author: 0xavi0

pkg/git/remote.go

@@ -138,17 +138,6 @@ func (r *Remote) LatestBranchCommit(ctx context.Context, branch string) (string,
 		return "", err
 	}
 
-	// check if the url is one of the supported for getting the last commit with a specific commits url
-	commitsURL := getVendorCommitsURL(r.URL, branch)
-	if commitsURL != "" {
-		// it is supported. Get the last commit with the vendor's url
-		// (this is faster than running a whole ls-remote like operation)
-		if commit, err := latestCommitFromCommitsURL(ctx, commitsURL, r.Options); err == nil {
-			// in case of error it tries the full List operation
-			return commit, nil
-		}
-	}
-
 	refBranch := formatRefForBranch(branch)
 
 	refs, err := r.Lister.List(false)

pkg/webhook/webhook.go

@@ -166,6 +166,18 @@ func (w *Webhook) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 					w.logAndReturn(rw, err)
 					return
 				}
+				if gitRepoFromCluster.Spec.DisablePolling {
+					// if polling is disabled, we add a small sleep to avoid potential race conditions between
+					// the webhook processing and the reconciliation that happens after the gitrepo update
+					// Refers to: https://github.com/rancher/fleet/issues/4837
+					select {
+					case <-time.After(1 * time.Second):
+					case <-ctx.Done():
+						// stop waiting if the request context has been canceled
+						w.logAndReturn(rw, ctx.Err())
+						return
+					}
+				}
 				orig := gitRepoFromCluster.DeepCopy()
 				gitRepoFromCluster.Status.WebhookCommit = revision
 				// if PollingInterval is not set and webhook is configured, set it to 1 hour