Webhooks

A webhook is a POST request sent to a URL that you define in Docker Hub or another registry. Use webhooks to trigger an action in response to an event such as a repository push.

{% hint style="info" %} This functionality is only available in Portainer Business Edition. {% endhint %}

{% hint style="info" %} Webhooks are only available on non-Edge environments (environments running Portainer Server or Portainer Agent, not the Portainer Edge Agent). This is because the tunnel to the Portainer Edge Agent is only opened on-demand, and therefore would mean there is no way to expose a webhook permanently. {% endhint %}

Enabling a stack webhook

From the menu select Stacks then select the container that you want to configure the webhook for. Then select the Editor tab.

Scroll down to the Webhooks section and toggle the Create a stack webhook option on. When the URL appears, click Copy link. This URL will be used to configure the webhook in your chosen registry.

This example shows how to trigger the webhook using redeploy:

<form action="https://portainer:9443/api/stacks/webhooks/638e6967-ef77-4906-8af8-236800621360" method="post">
  Redeploy stack containers with latest image of same tag <input type="submit" />
</form>

This example shows how to trigger the webhook to update the stack to use a different image tag:

<form action="https://portainer:9443/api/stacks/webhooks/638e6967-ef77-4906-8af8-236800621360?tag=latest" method="post">
  Update stack container images with different tag <input type="submit" />
</form>

Preventing a pull

In some cases you may want to override the pulling of images when using the webhook to do a redeploy. In that scenario, you can specify pullimage=false as a parameter on your webhook to disable pulling of images.

{% hint style="info" %} This option is only available in Portainer Business Edition. {% endhint %}

<form action="https://portainer:9443/api/stacks/webhooks/638e6967-ef77-4906-8af8-236800621360?pullimage=false" method="post">
  Update stack without pulling images <input type="submit" />
</form>

Using environment variables with webhooks

When triggering a webhook, environment variables can be passed through the endpoint and referenced within stacks' compose files.

To specify an environment variable on a webhook, add it as a variable to the URL. For example, to pass a SERVICE_TAG variable with the value development:

https://portainer:9443/api/stacks/webhooks/1d251d96-fb34-4172-a0a1-d0655467b897?SERVICE_TAG=development

To reference the SERVICE_TAG variable in your compose file with a fallback to the value stable:

services:
  my-service:
    image: repository/image:${SERVICE_TAG:-stable}

Configuring the webhook in Docker Hub

To finish the configuration, refer to Docker's own documentation.