GitHub API rate limit exceeded

[ShotaKitazawa]

GitHub API の rate limit に引っかがってしまったので、以下あたりを見直す

• busy wait でめちゃくちゃ GitHub API を叩いてしまっていないか
• resync period の値を延ばせるか

2021-12-26T03:29:37.963Z        ERROR   controller.reviewapp    Reconciler error        {"reconciler group": "dreamkast.cloudnativedays.jp", "reconciler kind": "ReviewApp", "name": "dreamkast-dk-cloudnativedaysjp-dreamkast-1055", "namespace": "reviewapp-operator-system", "error": "GET https://api.github.com/users/showks-containerdaysjp: 403 API rate limit exceeded for user ID 44684172. [rate reset in 5m28s]: GET https://api.github.com/users/showks-containerdaysjp: 403 API rate limit exceeded for user ID 44684172. [rate reset in 5m28s]", "errorVerbose": "GET https://api.github.com/users/showks-containerdaysjp: 403 API rate limit exceeded for user ID 44684172. [rate reset in 5m28s]:\n    github.com/cloudnativedaysjp/reviewapp-operator/gateways.(*GitHub).WithCredential\n        /workspace/gateways/github.go:66\n  - GET https://api.github.com/users/showks-containerdaysjp: 403 API rate limit exceeded for user ID 44684172. [rate reset in 5m28s]"}
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func2.2
        /go/pkg/mod/sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:227

[ShotaKitazawa]

golang.org/x/sync/singleflight を使って、「n秒以内の同様の API リクエストは singleflight させる」ようにしたほうがいいかも

[ShotaKitazawa]

In version v0.1.2, I implemented with below policy.

• prepare ReviewApp object's Status.Sync.SyncedPullRequest to store PullRequest information
• ReviewAppManager controller update to ReviewApp object's Status.Sync.SyncedPullRequest
  • I tried to decrease request to GitHub API by ReviewApp controller (hooked each ReviewApp objects).

However, above "updating by ReviewAppManager controller-side" implementation causes the action of updating all of ReviewApp object's status, which has below problems.

• Because ReviewAppManager controller own ReviewApp, ReviewAppManager reconciler was hooked every patched ReviewApp object from ReviewAppManager controller. (It is busy loop!)
• conflict in process of patching ReviewApp object's status between ReviewAppManager and ReviewApp controllers.
  • cf.
    1. ReviewAppManager controller get ReviewApp object.
    2. ReviewApp controller update ReviewApp object's status.
    3. ReviewAppManager controller update ReviewApp object's status.
       • Because ReviewAppManager controller calculate difference at "sequence 1" in controller-side, updation in "sequence 2" is lost.

approach

I will declare new CR: PullRequestCache.
ReviewAppManager and ReviewApp controller will refer to PullRequestChace object. This object's update don't cause to hook any Reconciler.