Slack webhook Cloud Functions for Google Cloud Container Builder

index.js

const IncomingWebhook = require("@slack/client").IncomingWebhook
const SLACK_WEBHOOK_URL = "SLACK_WEBHOOK_URL"

const webhook = new IncomingWebhook(SLACK_WEBHOOK_URL)

// subscribe is the main function called by Cloud Functions.
module.exports.slackSubscribe = (event, callback) => {
    const build = eventToBuild(event.data.data)

    // Skip if the current status is not in the status list.
    // Add additional statues to list if you'd like:
    // QUEUED, WORKING, SUCCESS, FAILURE,
    // INTERNAL_ERROR, TIMEOUT, CANCELLED
    const status = ["SUCCESS", "FAILURE", "INTERNAL_ERROR", "TIMEOUT"]
    if (status.indexOf(build.status) === -1) {
        return callback()
    }

    // Send message to Slack.
    const message = createSlackMessage(build)
    webhook.send(message, callback)
}

// eventToBuild transforms pubsub event message to a build object.
const eventToBuild = data => {
    return JSON.parse(new Buffer(data, "base64").toString())
}

const buildColor = status => {
    switch (status) {
        case "SUCCESS":
            return "good"
        case "FAILURE":
            return "danger"
        case "INTERNAL_ERROR":
            return "danger"
        default:
            return "#999999"
    }
}

// createSlackMessage create a message from a build object.
const createSlackMessage = build => {
    var message = {
        unfurl_links: false,
        unfurl_media: false
    }
    if (build.status == "SUCCESS") {
        message.text = `Service was deployed: <${
            build.logUrl
        }|${build.sourceProvenance.resolvedRepoSource.commitSha.substring(0, 7)}>`
    } else {
        message.text = `Failed to deploy: <${
            build.logUrl
        }|${build.sourceProvenance.resolvedRepoSource.commitSha.substring(0, 7)}>`
    }
    return message
}

package.json

{
    "name": "google-container-slack",
    "version": "0.0.1",
    "description":
        "Slack integration for Google Cloud Container Builder, using Google Cloud Functions",
    "main": "index.js",
    "dependencies": {
        "@slack/client": "3.9.0"
    }
}

setup.txt

Setup Slack Webhook

0/  Create a new Slack app: "YOUR_APP_NAME Deploy"
    https://api.slack.com/apps?new_app=1

1/  Add 'Incoming Webhook' and Activate it. Then click 'Add New Webhook to Workspace'
    and pick the channel you want to post to. Copy the webhook URL to use in step 4.

2/  Create Cloud Storage bucket:

    $ gsutil mb gs://[STAGING_BUCKET_NAME] Creating
    gs://[PROJECT-ID]_cloudbuilds/[STAGING_BUCKET_NAME]...

3/  Create a directory on local system for the function code:

    $ mkdir ~/gcb_slack $ cd ~/gcb_slack

4/  Add files to directory: index.js and package.json. Replace [SLACK-WEBHOOK]
    with the Slack webhook URL.

5/  Deploy the subscribe function with a Cloud Pub/Sub trigger, run the following
    command in the gcb_slack directory:

    $ gcloud beta functions deploy slackSubscribe --stage-bucket [STAGING_BUCKET_NAME] --trigger-topic cloud-builds