DEMO Alerts amp Providers

In this tutorial, you’ll configure the Flux Notification Controller to automatically send GitOps alerts to a Slack channel. By the end, you will have a working Slack App, Flux provider, and alert definitions driving real-time notifications.

1. Prepare Your Slack Workspace and Channel

If you don’t have a Slack workspace yet, create one by following Slack’s Help Center instructions:

The image shows a Slack Help Center webpage with instructions on creating a workspace for a team, including steps for desktop, iOS, and Android.

Once your workspace is ready, create a new channel (public or private) for Flux alerts. In this demo, we’ll use flux-alerts-channel:

The image shows a Slack workspace with a private channel named "flux-alerts-channel" that has just been created. The interface displays the channel's name, a welcome message, and a user who joined the channel.

If you need to customize the channel settings, use the channel-creation pop-up:

2. Create and Configure a Slack App

2.1 Create the Slack App

Go to the Slack API dashboard.
Click Create an App, give it a name (e.g., Flux Alerts Application), and select your workspace.

The image shows a Slack API interface where a user is naming an app "Flux Alert" and choosing a workspace to develop it in. There are options to cancel or create the app.

2.2 Configure OAuth & Permissions

Under Features → OAuth & Permissions, add the following Bot Token Scopes:

Scope	Description
chat:write	Send messages as the app
channels:read	Read public channel information
chat:write.customize	Send messages with a custom avatar

The image shows the Slack API interface, specifically the "OAuth & Permissions" section, where options for advanced token security and OAuth tokens for a workspace are displayed.

After adding the scopes, install the app:

The image shows a Slack API settings page with a list of bot token scopes, including permissions like "chat:write" and "channels:read." There's a success message at the top indicating changes have been saved.

On the authorization screen, click Allow:

The image shows a Slack authorization page where the Flux Alerts Application is requesting permission to access the "mcd-level2" Slack workspace. It includes options to view content and perform actions in channels and conversations, with "Cancel" and "Allow" buttons.

Once installed, copy the Bot User OAuth Token from the OAuth & Permissions page.

The image shows a Slack API settings page focused on OAuth & Permissions, displaying options for token security and an OAuth token for a workspace.

Keep your Bot User OAuth Token secure. Treat it like any sensitive credential.

2.3 Invite the Bot to Your Alert Channel

If your alerts channel is private, you must add the app as a member:

The image shows a Slack workspace interface with a private channel named "flux-alerts-channel" open. A dropdown menu is visible, offering options to notify everyone in the channel.

Once invited, you’ll see a confirmation in the channel:

The image shows a Slack workspace with a private channel named "flux-alerts-channel." It includes messages about a user joining the channel and an application being added.

3. Configure Flux Notification Controller

3.1 Create the Slack Bot Token Secret

Store your Slack Bot Token in the flux-system namespace:

kubectl -n flux-system create secret generic slack-bot-token \
  --from-literal=token=xoxb-xxxxxxxxxxxxxxxxxxxx

Replace xoxb-xxxxxxxxxxxxxxxxxxxx with your actual Bot User OAuth Token.

3.2 Define the Slack Provider

Flux’s Provider API lets you specify how notifications are sent. See Flux Notification Providers:

The image shows a webpage from the Flux documentation listing various notification providers such as Discord, GitHub, Google Chat, and Slack. The left sidebar contains navigation links for different components and guides.

Option A: Apply a YAML manifest
Create notification-provider-slack.yaml:

apiVersion: notification.toolkit.fluxcd.io/v1beta2
kind: Provider
metadata:
  name: notification-provider-slack
  namespace: flux-system
spec:
  type: slack
  channel: flux-alerts-channel
  address: https://slack.com/api/chat.postMessage
  secretRef:
    name: slack-bot-token
  username: flux-bot

Apply it:

kubectl -n flux-system apply -f notification-provider-slack.yaml

Option B: Generate with the Flux CLI

flux create provider notification slack notification-provider-slack \
  --channel flux-alerts-channel \
  --username flux-bot \
  --secret-ref slack-bot-token \
  --address https://slack.com/api/chat.postMessage \
  --export > notification-provider-slack.yaml

3.3 Define an Alert

Alerts let you filter events by severity and resource type before sending them via your provider. Create notification-alert-slack.yaml:

apiVersion: notification.toolkit.fluxcd.io/v1beta2
kind: Alert
metadata:
  name: notification-alert-slack
  namespace: flux-system
spec:
  eventSeverity: info
  eventSources:
    - kind: Kustomization; name: "*"
    - kind: GitRepository; name: "*"
    - kind: Bucket; name: "*"
    - kind: OCIRepository; name: "*"
    - kind: HelmChart; name: "*"
    - kind: HelmRepository; name: "*"
    - kind: HelmRelease; name: "*"
    - kind: ImageRepository; name: "*"
    - kind: ImagePolicy; name: "*"
    - kind: ImageUpdateAutomation; name: "*"
  providerRef:
    name: notification-provider-slack

Or generate with the Flux CLI:

flux create alert notification-alert-slack \
  --event-severity info \
  --provider-ref notification-provider-slack \
  --event-source Kustomization/* \
  --event-source GitRepository/* \
  --event-source Bucket/* \
  --event-source OCIRepository/* \
  --event-source HelmChart/* \
  --event-source HelmRepository/* \
  --event-source HelmRelease/* \
  --event-source ImageRepository/* \
  --event-source ImagePolicy/* \
  --event-source ImageUpdateAutomation/* \
  --export > notification-alert-slack.yaml

Apply your Alert:

kubectl -n flux-system apply -f notification-alert-slack.yaml

4. Confirm Setup

Make sure Flux picks up your changes and that both the provider and alert are READY:

flux reconcile source git flux-system
flux get alert
flux get providers notification

5. Trigger and Observe Notifications

Change something in your Git repository—for example, reduce the replica count in your deployment:

# in bb-app-source/2-demo/deployment.yaml
spec:
  replicas: 1

Commit and push the update. Once Flux reconciles, you will see a notification in flux-alerts-channel:

The image shows a Slack workspace with a channel named "flux-alerts-channel" where users and bots are interacting, including messages about a Flux Alerts Application and a git repository update.

6. Verify the Update in Kubernetes

Confirm that your deployment reflects the new replica count:

kubectl -n 2-demo get pods

Congratulations! You have successfully configured Flux Notification Controller to deliver Slack alerts for all your Flux events.

GitOps Overview

Flux Overview

Source and Kustomize Controller

Helm Controller and OCI Registry

Image Automation Controller

Secret Management & Sign Verification

Notification Controller

Monitoring & User Interface

DEMO Alerts amp Providers

1. Prepare Your Slack Workspace and Channel

2. Create and Configure a Slack App

2.1 Create the Slack App

2.2 Configure OAuth & Permissions

2.3 Invite the Bot to Your Alert Channel

3. Configure Flux Notification Controller

3.1 Create the Slack Bot Token Secret

3.2 Define the Slack Provider

3.3 Define an Alert

4. Confirm Setup

5. Trigger and Observe Notifications

6. Verify the Update in Kubernetes

Links and References

Watch Video

​1. Prepare Your Slack Workspace and Channel

​2. Create and Configure a Slack App

​2.1 Create the Slack App

​2.2 Configure OAuth & Permissions

​2.3 Invite the Bot to Your Alert Channel

​3. Configure Flux Notification Controller

​3.1 Create the Slack Bot Token Secret

​3.2 Define the Slack Provider

​3.3 Define an Alert

​4. Confirm Setup

​5. Trigger and Observe Notifications

​6. Verify the Update in Kubernetes

​Links and References

Watch Video

1. Prepare Your Slack Workspace and Channel

2. Create and Configure a Slack App

2.1 Create the Slack App

2.2 Configure OAuth & Permissions

2.3 Invite the Bot to Your Alert Channel

3. Configure Flux Notification Controller

3.1 Create the Slack Bot Token Secret

3.2 Define the Slack Provider

3.3 Define an Alert

4. Confirm Setup

5. Trigger and Observe Notifications

6. Verify the Update in Kubernetes

Links and References