CI Notifier

A Slack slash command that sends you a personal DM when a CircleCI pipeline on any branch completes.

/ci-notify Hydra main
/ci-notify Atlas my-feature-branch

You get an immediate confirmation in Slack, then a DM when the pipeline finishes — pass, fail, or cancel.

Architecture

Slack /ci-notify command
        │
        ▼
  Cloud Run /slash          ← validates Slack signature, ACKs within 3s
        │
        ▼
  Cloud Tasks queue         ← schedules poll tasks every 30s
        │
        ▼
  Cloud Run /poll           ← queries CircleCI API v2 for workflow status
        │
        ├── still running → reschedule poll
        │
        └── complete → Slack DM to the user who invoked the command

Services involved:

Service	Role
Slack CI Notifier app	Receives slash commands, sends DMs
GCP Cloud Run (ci-notifier)	Python/Flask service hosting /slash and /poll
GCP Cloud Tasks (ci-pipeline-poller)	Schedules polling tasks
CircleCI API v2	Source of pipeline and workflow status

Prerequisites

• GCP project with Cloud Run and Cloud Tasks APIs enabled
• Slack app with a /ci-notify slash command and chat:write + im:write bot scopes
• CircleCI personal API token

Setup

1. Enable GCP APIs

gcloud services enable run.googleapis.com cloudtasks.googleapis.com cloudbuild.googleapis.com \
  --project=<your-gcp-project>

2. Create the Cloud Tasks queue

gcloud tasks queues create ci-pipeline-poller \
  --location=us-central1 \
  --project=<your-gcp-project>

3. Create a Slack app

1. Go to api.slack.com/apps → Create New App → From scratch
2. Under OAuth & Permissions, add bot scopes: chat:write, im:write
3. Install the app to your workspace and copy the Bot User OAuth Token (xoxb-...)
4. Under Basic Information → App Credentials, copy the Signing Secret
5. Under Slash Commands, create /ci-notify pointing at <your-cloud-run-url>/slash

4. Deploy

Copy deploy.sh.example to deploy.sh, fill in the values, then run:

bash deploy.sh

After the first deploy, update the SERVICE_URL env var with the Cloud Run URL:

gcloud run services update ci-notifier \
  --region us-central1 \
  --project <your-gcp-project> \
  --update-env-vars SERVICE_URL=<your-cloud-run-url>

Environment variables

Variable	Description
CIRCLECI_TOKEN	CircleCI personal API token
SLACK_BOT_TOKEN	Bot User OAuth Token (xoxb-...)
SLACK_SIGNING_SECRET	Slack app signing secret
INTERNAL_TOKEN	Shared secret for Cloud Tasks → Cloud Run auth (generate with openssl rand -hex 32)
GCP_PROJECT	GCP project ID
GCP_LOCATION	GCP region (default: us-central1)
TASKS_QUEUE	Cloud Tasks queue name
SERVICE_URL	Public Cloud Run URL
ORG_PREFIX	Default CircleCI org prefix (default: github/outputinc)
POLL_INTERVAL_SECONDS	How often to poll CircleCI in seconds (default: 30)

Notification format

Success:

✅ Hydra pipeline #10437 on `main` — success

Failure:

❌ Hydra pipeline #10438 on `main` — failed
Failed workflows: `main_flow`

Redeploying

cd ~/repos/ci-notifier && bash deploy.sh