Slack Trigger¶
The Slack trigger is used to send a custom message to a desired Slack channel in a Slack workspace. The intended use is for notifications for a build pipeline, but can be used for any notification scenario.
Prerequisite¶
-
Deploy the eventbus in the namespace.
-
Make sure to have a Slack workspace setup you wish to send a message to.
-
Create a webhook event-source.
kubectl -n argo-events apply -f https://raw.githubusercontent.com/argoproj/argo-events/stable/examples/event-sources/webhook.yaml -
Set up port-forwarding to expose the http server. We will use port-forwarding here.
kubectl port-forward -n argo-events <event-source-pod-name> 12000:12000
Create a Slack App¶
We need to create a Slack App which will send messages to your Slack Workspace. We will add OAuth Permissions and add the OAuth token to the k8s cluster via a secret.
-
Create a Slack app by clicking
Create New Appat the Slack API Page. Name your app and choose your intended Slack Workspace. -
Navigate to your app, then to
Features > OAuth & Permissions. -
Scroll down to
Scopesand add the scopeschannels:join,channels:read,groups:readandchat:writeto the Bot Token Scopes. -
Scroll to the top of the
OAuth & Permissionspage and clickInstall App to Workspaceand follow the install Wizard. -
You should land back on the
OAuth & Permissionspage. Copy your app's OAuth Access Token. This will allow the trigger to act on behalf of your newly created Slack app. -
Create a kubernetes secret with the OAuth token in your cluster.
kubectl create secret generic slack-secret --from-literal=token=$SLACK_OAUTH_TOKEN
Slack Trigger¶
We will set up a basic slack trigger and send a default message, and then a dynamic custom message.
-
Create a sensor with Slack trigger. We will discuss the trigger details in the following sections.
kubectl -n argo-events apply -f https://raw.githubusercontent.com/argoproj/argo-events/stable/examples/sensors/slack-trigger.yaml -
Send a http request to the event-source-pod to fire the Slack trigger.
curl -d '{"text":"Hello, World!"}' -H "Content-Type: application/json" -X POST http://localhost:12000/exampleNote: The default slack-trigger will send the message "hello world" to the #general channel. You may change the default message and channel in slack-trigger.yaml under triggers.slack.channel and triggers.slack.message.
-
Alternatively, you can dynamically determine the channel and message based on parameterization of your event.
curl -d '{"channel":"random","message":"test message"}' -H "Content-Type: application/json" -X POST http://localhost:12000/example -
Great! But, how did the sensor use the event to customize the message and channel from the http request? We will see that in next section.
Parameterization¶
The slack trigger parameters have the following structure,
parameters:
- src:
dependencyName: test-dep
dataKey: body.channel
dest: slack.channel
- src:
dependencyName: test-dep
contextKey: body.message
dest: slack.message
The src is the source of event. It contains,
dependencyName: name of the event dependency to extract the event from.dataKey: to extract a particular key-value from event's data.contextKey: to extract a particular key-value from event' context.
The dest is the destination key within the result payload.
So, the above trigger parameters will generate a request payload as,
{
"channel": "channel_to_send_message",
"message": "message_to_send_to_channel"
}
Note: If you define both the contextKey and dataKey within a parameter item, then
the dataKey takes the precedence.
You can create any parameter structure you want. To get more info on how to generate complex event payloads, take a look at this library.
Other Capabilities¶
Configuring the sender of the Slack message:¶
- template:
name: slack-trigger
slack:
sender:
username: "Cool Robot"
icon: ":robot_face:" # emoji or url, e.g. https://example.com/image.png
Sending messages to Slack threads:¶
- template:
name: slack-trigger
slack:
thread:
messageAggregationKey: "abcdefg" # aggregate message by some key to send them to the same Slack thread
broadcastMessageToChannel: true # also broadcast the message from the thread to the channel
Sending attachments using Slack Attachments API:¶
- template:
name: slack-trigger
slack:
message: "hello world!"
attachments: |
[{
"title": "Attachment1!",
"title_link": "https://argoproj.github.io/argo-events/sensors/triggers/slack-trigger/",
"color": "#18be52",
"fields": [{
"title": "Hello1",
"value": "Hello World1",
"short": true
}, {
"title": "Hello2",
"value": "Hello World2",
"short": true
}]
}, {
"title": "Attachment2!",
"title_link": "https://argoproj.github.io/argo-events/sensors/triggers/slack-trigger/",
"color": "#18be52",
"fields": [{
"title": "Hello1",
"value": "Hello World1",
"short": true
}, {
"title": "Hello2",
"value": "Hello World2",
"short": true
}]
}]
Sending blocks using Slack Blocks API:¶
- template:
name: slack-trigger
slack:
blocks: |
[{
"type": "actions",
"block_id": "actionblock789",
"elements": [{
"type": "datepicker",
"action_id": "datepicker123",
"initial_date": "1990-04-28",
"placeholder": {
"type": "plain_text",
"text": "Select a date"
}
},
{
"type": "overflow",
"options": [{
"text": {
"type": "plain_text",
"text": "*this is plain_text text*"
},
"value": "value-0"
},
{
"text": {
"type": "plain_text",
"text": "*this is plain_text text*"
},
"value": "value-1"
},
{
"text": {
"type": "plain_text",
"text": "*this is plain_text text*"
},
"value": "value-2"
},
{
"text": {
"type": "plain_text",
"text": "*this is plain_text text*"
},
"value": "value-3"
},
{
"text": {
"type": "plain_text",
"text": "*this is plain_text text*"
},
"value": "value-4"
}
],
"action_id": "overflow"
},
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Click Me"
},
"value": "click_me_123",
"action_id": "button"
}
]
}]
The complete specification of Slack trigger is available here.