Git Webhook Configuration

Overview

Argo CD polls Git repositories every three minutes to detect changes to the manifests. To eliminate this delay from polling, the API server can be configured to receive webhook events. Argo CD supports Git webhook notifications from GitHub, GitLab, Bitbucket, Bitbucket Server and Gogs. The following explains how to configure a Git webhook for GitHub, but the same process should be applicable to other providers.

1. Create The WebHook In The Git Provider

In your Git provider, navigate to the settings page where webhooks can be configured. The payload URL configured in the Git provider should use the /api/webhook endpoint of your Argo CD instance (e.g. [https://argocd.example.com/api/webhook]). If you wish to use a shared secret, input an arbitrary value in the secret. This value will be used when configuring the webhook in the next step.

Add Webhook

2. Configure Argo CD With The WebHook Secret Optional)

Configuring a webhook shared secret is optional, since Argo CD will still refresh applications related to the Git repository, even with unauthenticated webhook events. This is safe to do since the contents of webhook payloads are considered untrusted, and will only result in a refresh of the application (a process which already occurs at three-minute intervals). If Argo CD is publicly accessible, then configuring a webhook secret is recommended to prevent a DDoS attack.

In the argocd-secret kubernetes secret, configure one of the following keys with the Git provider's webhook secret configured in step 1.

Provider K8s Secret Key
GitHub webhook.github.secret
GitLab webhook.gitlab.secret
BitBucket webhook.bitbucket.uuid
BitBucketServer webhook.bitbucketserver.secret
Gogs webhook.gogs.secret

Edit the Argo CD kubernetes secret:

kubectl edit secret argocd-secret -n argocd

TIP: for ease of entering secrets, kubernetes supports inputting secrets in the stringData field, which saves you the trouble of base64 encoding the values and copying it to the data field. Simply copy the shared webhook secret created in step 1, to the corresponding GitHub/GitLab/BitBucket key under the stringData field:

apiVersion: v1
kind: Secret
metadata:
  name: argocd-secret
  namespace: argocd
type: Opaque
data:
...

stringData:
  # github webhook secret
  webhook.github.secret: shhhh! it's a github secret

  # gitlab webhook secret
  webhook.gitlab.secret: shhhh! it's a gitlab secret

  # bitbucket webhook secret
  webhook.bitbucket.uuid: your-bitbucket-uuid

  # bitbucket server webhook secret
  webhook.bitbucketserver.secret: shhhh! it's a bitbucket server secret

  # gogs server webhook secret
  webhook.gogs.secret: shhhh! it's a gogs server secret

After saving, the changes should take effect automatically.