# Slack Notifications Architecture for CI/CD Pipeline Failures

**Document Version**: 1.0
**Date**: 2026-01-31
**Architect**: Morgan (Solution Architect)
**Requester**: Alessandro
**Status**: DESIGN APPROVED

---

## Executive Summary

Architecture for reliable Slack notifications when GitHub Actions CI/CD pipeline fails, using GitHub native integration with Slack webhooks. This design prioritizes reliability, security, minimal maintenance, and rich failure context.

**Recommended Solution**: GitHub Actions marketplace action `slackapi/slack-github-action@v2.0.0` with Incoming Webhook integration.

**Key Benefits**:
- Zero infrastructure overhead (serverless)
- Officially maintained by Slack (high reliability)
- Native GitHub Secrets integration (secure)
- Rich context (commit, branch, logs, failure reason)
- Simple configuration (< 20 lines YAML)

---

## 1. Requirements Analysis

### Functional Requirements
- **FR-1**: Notify Slack when CI/CD pipeline fails
- **FR-2**: Include commit SHA, branch, committer, failure reason, workflow run URL
- **FR-3**: Support multiple notification channels (e.g., team channel, individual DMs)
- **FR-4**: Distinguish between different failure stages (fast checks, tests, build, release)

### Non-Functional Requirements
- **NFR-1 Reliability**: 99.9% notification delivery (every failure must notify)
- **NFR-2 Security**: No secrets exposed in code or logs
- **NFR-3 Maintenance**: Zero maintenance overhead (use managed service)
- **NFR-4 Latency**: Notification within 30 seconds of failure
- **NFR-5 Cost**: Zero additional infrastructure cost

### Constraints
- Must use GitHub Actions (existing CI/CD platform)
- Must use existing Slack workspace
- Cannot introduce new infrastructure (no servers, databases)
- Must follow GitHub security best practices (secrets management)

---

## 2. Architecture Decision Record (ADR-001): Slack Integration Approach

### Status
**ACCEPTED** (2026-01-31)

### Context
Three primary integration approaches evaluated:

**Option A: GitHub Actions Marketplace - slackapi/slack-github-action**
- Official Slack action maintained by Slack team
- Uses Slack Incoming Webhooks or Bot Token
- MIT license, 4.2k GitHub stars, actively maintained
- Last release: December 2024
- Built-in GitHub context integration

**Option B: Custom webhook POST with curl**
- Direct HTTP POST to Slack webhook URL
- No dependencies on third-party actions
- Requires manual JSON formatting
- Less GitHub context integration

**Option C: Slack App with GitHub integration**
- Full Slack app with OAuth
- Rich interactive features
- Significantly more complex setup
- Requires app installation and permission management

### Decision
**Selected: Option A (slackapi/slack-github-action@v2.0.0)**

### Rationale

**Why Option A is Optimal**:

1. **Reliability (NFR-1)**:
   - Officially maintained by Slack (high SLA)
   - Battle-tested (4.2k+ stars, used by thousands)
   - Automatic retries built-in
   - GitHub Actions runtime ensures execution

2. **Security (NFR-2)**:
   - Native GitHub Secrets integration
   - Webhook URL never exposed in logs
   - Follows GitHub security best practices
   - No third-party secret management needed

3. **Maintenance (NFR-3)**:
   - Zero infrastructure (serverless)
   - Slack team maintains action
   - Automatic security patches
   - Semantic versioning (v2.0.0 pinning)

4. **Developer Experience**:
   - Rich GitHub context (commit, branch, user, logs)
   - JSON template system for custom messages
   - Slack Block Kit support (rich formatting)
   - Excellent documentation

5. **Open Source (Core Principle)**:
   - MIT license
   - Active community (100+ contributors)
   - Transparent codebase (security audit possible)
   - No vendor lock-in (webhook standard)

**Why NOT Option B**:
- More code to maintain (JSON template, error handling)
- Missing built-in GitHub context variables
- No automatic retries
- Higher risk of formatting errors

**Why NOT Option C**:
- Over-engineering for simple notification need
- Requires app installation (organizational overhead)
- More complex secret management (OAuth tokens)
- Higher maintenance burden

### Consequences

**Positive**:
- Simple YAML configuration (< 20 lines)
- Immediate implementation (no infrastructure setup)
- Rich failure context automatically included
- Slack team handles breaking changes

**Negative**:
- Dependency on third-party action (mitigation: pin version, fork if needed)
- Limited to Slack webhook capabilities (acceptable for notification use case)

**Trade-offs Accepted**:
- Slack webhook rate limits (600 messages/minute) - acceptable for CI/CD notifications
- No interactive features (buttons, modals) - not needed for failure notifications

---

## 3. Technology Stack

### GitHub Actions Integration
- **Action**: `slackapi/slack-github-action@v2.0.0` (official Slack action)
- **License**: MIT
- **Maintenance**: Active (last release Dec 2024)
- **GitHub**: https://github.com/slackapi/slack-github-action
- **Community**: 4.2k stars, 100+ contributors

### Slack Integration
- **Method**: Incoming Webhooks
- **Authentication**: Webhook URL (stored in GitHub Secrets)
- **Message Format**: Slack Block Kit (rich formatting)
- **Rate Limits**: 1 message/second per webhook, 600/minute workspace-wide

### Secret Management
- **Storage**: GitHub Secrets (repository or organization level)
- **Access Control**: RBAC via GitHub permissions
- **Rotation**: Manual rotation (webhook URL regeneration)

---

## 4. Component Architecture

### 4.1 High-Level Architecture

```
┌─────────────────────────────────────────────────────┐
│ GitHub Actions CI/CD Pipeline                       │
│                                                      │
│  ┌────────────┐   ┌────────────┐   ┌────────────┐  │
│  │  Stage 1   │   │  Stage 2   │   │  Stage N   │  │
│  │Fast Checks │──>│   Tests    │──>│   Build    │  │
│  └────────────┘   └────────────┘   └────────────┘  │
│         │                │                │         │
│         └────────────────┴────────────────┘         │
│                      │                              │
│                   FAILURE                            │
│                      │                              │
│         ┌────────────▼────────────┐                 │
│         │ notify-slack Job        │                 │
│         │ (if: failure())         │                 │
│         └────────────┬────────────┘                 │
└──────────────────────┼──────────────────────────────┘
                       │
                       │ GitHub Secret:
                       │ SLACK_WEBHOOK_URL
                       │
          ┌────────────▼────────────┐
          │ Slack API               │
          │ Incoming Webhook        │
          └────────────┬────────────┘
                       │
          ┌────────────▼────────────┐
          │ Slack Workspace         │
          │ #engineering-alerts     │
          └─────────────────────────┘
```

### 4.2 Notification Flow Sequence

```
┌──────────┐      ┌──────────┐      ┌─────────┐      ┌─────────┐
│ Pipeline │      │ Notify   │      │ Slack   │      │ Slack   │
│  Stage   │      │  Job     │      │  API    │      │ Channel │
└────┬─────┘      └────┬─────┘      └────┬────┘      └────┬────┘
     │                 │                  │                │
     │ FAILURE         │                  │                │
     ├────────────────>│                  │                │
     │                 │                  │                │
     │                 │ Extract context  │                │
     │                 │ (commit, branch, │                │
     │                 │  user, logs URL) │                │
     │                 │──────┐           │                │
     │                 │      │           │                │
     │                 │<─────┘           │                │
     │                 │                  │                │
     │                 │ POST /services/  │                │
     │                 │  {webhook_id}    │                │
     │                 │  (JSON payload)  │                │
     │                 ├─────────────────>│                │
     │                 │                  │                │
     │                 │                  │ Format message │
     │                 │                  │ (Block Kit)    │
     │                 │                  ├───────────────>│
     │                 │                  │                │
     │                 │                  │                │
     │                 │<─────────────────┤  200 OK        │
     │                 │                  │                │
     │                 │ Log success      │                │
     │                 │──────┐           │                │
     │                 │      │           │                │
     │                 │<─────┘           │                │
     │                 │                  │                │
```

### 4.3 Error Handling Flow

```
┌─────────────────────┐
│ Pipeline Failure    │
└──────────┬──────────┘
           │
           ▼
┌─────────────────────┐
│ notify-slack Job    │
│ if: failure()       │
└──────────┬──────────┘
           │
           ▼
     ┌────────────┐
     │ Retrieve   │
     │ WEBHOOK_URL│
     │ from Secret│
     └─────┬──────┘
           │
           ▼
    ┌──────────────┐      ┌──────────────────┐
    │ POST to Slack│─────>│ Slack API        │
    │ with retry   │      │ Returns 200 OK   │
    └──────┬───────┘      └──────────────────┘
           │
           │
           ▼
      SUCCESS
           │
           └─────> Pipeline marked complete

FAILURE SCENARIOS:

Scenario 1: Webhook URL invalid
  ├─> Slack returns 404 Not Found
  ├─> GitHub Actions logs error
  ├─> Job fails (red X in Actions UI)
  └─> Manual investigation required

Scenario 2: Network timeout
  ├─> slackapi action retries (3 attempts)
  ├─> If all fail: Job marked failed
  └─> GitHub Actions logs error

Scenario 3: Rate limit exceeded
  ├─> Slack returns 429 Too Many Requests
  ├─> slackapi action waits and retries
  └─> Notification eventually delivered

Fallback Strategy:
  - GitHub Actions UI always shows failure (primary visibility)
  - Email notifications (GitHub native, if enabled)
  - Slack notification is ENHANCEMENT, not single point of visibility
```

---

## 5. Security Architecture

### 5.1 Secret Management

**GitHub Secrets Configuration**:

```yaml
# Stored in: Repository Settings > Secrets and variables > Actions

SLACK_WEBHOOK_URL:
  Value: "https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXX"
  Access: Actions only (not accessible in PR from forks)
  Encryption: GitHub AES-256 encryption at rest
  Transmission: TLS 1.3 in transit
```

**Security Best Practices**:

1. **Principle of Least Privilege**:
   - Use Incoming Webhook (read-only to specific channel)
   - NOT Bot Token (broader permissions)
   - Webhook tied to single channel only

2. **Secret Rotation**:
   - Regenerate webhook URL quarterly
   - Revoke old webhook immediately after rotation
   - Document rotation procedure

3. **Access Control**:
   - Repository secrets accessible only to repo admins
   - Actions cannot expose secrets in logs (GitHub sanitizes)
   - Forks cannot access secrets (GitHub security model)

4. **Audit Logging**:
   - GitHub audit log tracks secret access
   - Slack audit log tracks webhook usage
   - Monitor for unauthorized access attempts

### 5.2 Webhook URL Protection

**GitHub Security Features**:
- Automatic secret sanitization in logs (replaces with `***`)
- Secrets unavailable in pull requests from forks
- API rate limiting prevents brute force attacks

**Slack Security Features**:
- Webhook URL is unguessable (cryptographically random)
- Scoped to single channel (cannot post elsewhere)
- Can be revoked instantly via Slack admin panel

**Risk Mitigation**:

| Risk | Likelihood | Impact | Mitigation |
|------|------------|--------|------------|
| Secret exposure in logs | Very Low | Medium | GitHub automatic sanitization |
| Webhook URL leaked | Low | Medium | Quarterly rotation, instant revocation |
| Rate limit abuse | Very Low | Low | Slack rate limiting (600/min) |
| Unauthorized access | Very Low | Low | Repository RBAC, audit logs |

---

## 6. Notification Content Design

### 6.1 Message Structure

**Required Information** (per FR-2):
- Commit SHA (short: 7 chars)
- Branch name
- Committer name and email
- Failure reason (job name + stage)
- Workflow run URL (direct link to logs)
- Timestamp of failure

**Enhanced Information**:
- Commit message (first line)
- Repository name
- Workflow name
- Failure emoji for quick visual recognition

### 6.2 Slack Block Kit Template

```json
{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "🚨 CI/CD Pipeline Failed",
        "emoji": true
      }
    },
    {
      "type": "section",
      "fields": [
        {
          "type": "mrkdwn",
          "text": "*Repository:*\n<https://github.com/${{ github.repository }}|${{ github.repository }}>"
        },
        {
          "type": "mrkdwn",
          "text": "*Branch:*\n`${{ github.ref_name }}`"
        },
        {
          "type": "mrkdwn",
          "text": "*Commit:*\n<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|${{ github.sha }}>"
        },
        {
          "type": "mrkdwn",
          "text": "*Author:*\n${{ github.actor }}"
        },
        {
          "type": "mrkdwn",
          "text": "*Workflow:*\n${{ github.workflow }}"
        },
        {
          "type": "mrkdwn",
          "text": "*Failed Job:*\n${{ github.job }}"
        }
      ]
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*Commit Message:*\n${{ github.event.head_commit.message }}"
      }
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "View Logs",
            "emoji": true
          },
          "url": "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}",
          "style": "danger"
        },
        {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "View Commit",
            "emoji": true
          },
          "url": "https://github.com/${{ github.repository }}/commit/${{ github.sha }}"
        }
      ]
    },
    {
      "type": "context",
      "elements": [
        {
          "type": "mrkdwn",
          "text": "⏰ Failed at: <!date^${{ github.event.head_commit.timestamp }}^{date_num} {time_secs}|timestamp>"
        }
      ]
    }
  ]
}
```

**Message Preview**:

```
🚨 CI/CD Pipeline Failed

Repository: nWave-ai/nwave-dev
Branch: master

Commit: a1b2c3d
Author: Alessandro

Workflow: CI/CD Pipeline
Failed Job: test

Commit Message:
feat(agents): add new capability

[View Logs] [View Commit]

⏰ Failed at: 2026-01-31 14:23:45
```

### 6.3 Notification Targeting Strategy

**Primary Notification Channel**: `#engineering-alerts`
- All pipeline failures posted here
- Visible to entire engineering team
- Searchable history

**Conditional Notifications** (future enhancement):
- Critical failures (master branch): `#critical-alerts` + `@channel`
- Pull request failures: Mention PR author `@username`
- Deployment failures: `#devops-alerts`

---

## 7. Implementation Design

### 7.1 GitHub Actions YAML Configuration

**File**: `.github/workflows/ci-cd.yml`

**New Job**: `notify-slack` (added after all stages)

```yaml
# ===========================================================================
# NOTIFICATION: SLACK ALERTS - Always run on failure
# ===========================================================================

notify-slack:
  name: "Slack Notification"
  runs-on: ubuntu-latest
  timeout-minutes: 2
  # Run ONLY if any previous job failed AND on master/develop branches
  if: |
    failure() &&
    (github.ref == 'refs/heads/master' || github.ref == 'refs/heads/develop')
  needs: [commitlint, code-quality, file-quality, security-checks, framework-validation, test, agent-sync, build, release]

  steps:
    - name: Send Slack notification
      uses: slackapi/slack-github-action@v2.0.0
      with:
        webhook-url: ${{ secrets.SLACK_WEBHOOK_URL }}
        payload: |
          {
            "blocks": [
              {
                "type": "header",
                "text": {
                  "type": "plain_text",
                  "text": "🚨 CI/CD Pipeline Failed",
                  "emoji": true
                }
              },
              {
                "type": "section",
                "fields": [
                  {
                    "type": "mrkdwn",
                    "text": "*Repository:*\n<https://github.com/${{ github.repository }}|${{ github.repository }}>"
                  },
                  {
                    "type": "mrkdwn",
                    "text": "*Branch:*\n`${{ github.ref_name }}`"
                  },
                  {
                    "type": "mrkdwn",
                    "text": "*Commit:*\n<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|`${{ github.sha }}`>"
                  },
                  {
                    "type": "mrkdwn",
                    "text": "*Author:*\n${{ github.actor }}"
                  },
                  {
                    "type": "mrkdwn",
                    "text": "*Workflow:*\n${{ github.workflow }}"
                  },
                  {
                    "type": "mrkdwn",
                    "text": "*Event:*\n${{ github.event_name }}"
                  }
                ]
              },
              {
                "type": "section",
                "text": {
                  "type": "mrkdwn",
                  "text": "*Commit Message:*\n${{ github.event.head_commit.message }}"
                }
              },
              {
                "type": "actions",
                "elements": [
                  {
                    "type": "button",
                    "text": {
                      "type": "plain_text",
                      "text": "View Logs",
                      "emoji": true
                    },
                    "url": "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}",
                    "style": "danger"
                  },
                  {
                    "type": "button",
                    "text": {
                      "type": "plain_text",
                      "text": "View Commit",
                      "emoji": true
                    },
                    "url": "https://github.com/${{ github.repository }}/commit/${{ github.sha }}"
                  }
                ]
              },
              {
                "type": "context",
                "elements": [
                  {
                    "type": "mrkdwn",
                    "text": "⏰ Failed at: <!date^${{ github.event.repository.updated_at }}^{date_num} {time_secs}|timestamp>"
                  }
                ]
              }
            ]
          }
      env:
        SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
```

### 7.2 Configuration Steps

**Step 1: Create Slack Incoming Webhook**

1. Go to Slack workspace: https://api.slack.com/apps
2. Create new app: "GitHub CI/CD Alerts"
3. Enable "Incoming Webhooks"
4. Click "Add New Webhook to Workspace"
5. Select channel: `#engineering-alerts`
6. Copy webhook URL (format: `https://hooks.slack.com/services/T.../B.../XXX`)

**Step 2: Store Webhook URL in GitHub Secrets**

1. Navigate to: `https://github.com/nWave-ai/nwave-dev/settings/secrets/actions`
2. Click "New repository secret"
3. Name: `SLACK_WEBHOOK_URL`
4. Value: Paste webhook URL
5. Click "Add secret"

**Step 3: Update CI/CD Workflow**

1. Add `notify-slack` job to `.github/workflows/ci-cd.yml`
2. Commit and push changes
3. Test by intentionally breaking a test

**Step 4: Verify Notification**

1. Trigger pipeline failure (modify test to fail)
2. Check Slack `#engineering-alerts` for notification
3. Verify all fields populated correctly
4. Click "View Logs" button to confirm URL works

---

## 8. Testing Strategy

### 8.1 Test Scenarios

**Test 1: Fast Checks Failure**
- Break ruff formatting
- Push to master
- Verify Slack notification with correct job name

**Test 2: Test Suite Failure**
- Modify test to fail
- Push to master
- Verify notification includes commit message and logs link

**Test 3: Build Failure (tags only)**
- Create tag with version mismatch
- Verify build fails and notification sent

**Test 4: Branch Filtering**
- Break test on feature branch
- Verify NO notification (only master/develop trigger)

**Test 5: Secret Sanitization**
- Check GitHub Actions logs
- Verify webhook URL appears as `***`

**Test 6: Network Failure Simulation**
- Temporarily revoke webhook URL
- Trigger failure
- Verify job fails gracefully with error log

### 8.2 Validation Criteria

| Criteria | Validation Method | Pass/Fail |
|----------|-------------------|-----------|
| Notification delivered | Check Slack channel | PASS if message appears |
| Correct information | Verify all fields populated | PASS if all data correct |
| Logs link works | Click "View Logs" button | PASS if redirects to Actions run |
| Secret protected | Check Actions logs | PASS if URL is `***` |
| Branch filtering | Trigger on feature branch | PASS if no notification |
| Error handling | Revoke webhook, trigger failure | PASS if job logs error |

---

## 9. Operational Considerations

### 9.1 Monitoring and Alerting

**Monitoring Points**:
- GitHub Actions job success rate (notify-slack job)
- Slack message delivery rate (Slack audit logs)
- Webhook URL access attempts (GitHub audit logs)

**Alerting Thresholds**:
- Alert if `notify-slack` job fails > 2 consecutive times
- Alert if no Slack notifications for > 24 hours (may indicate secret issue)

### 9.2 Maintenance Procedures

**Quarterly Maintenance**:
1. Review Slack audit logs for unauthorized webhook usage
2. Rotate webhook URL (regenerate and update GitHub Secret)
3. Verify notification format still renders correctly
4. Check for slackapi action updates (pin to new version if needed)

**Incident Response**:

| Incident | Detection | Response | SLA |
|----------|-----------|----------|-----|
| Notification not received | Manual check | Verify webhook URL valid, check GitHub logs | 1 hour |
| Secret exposed | GitHub alert | Revoke webhook, regenerate, update secret | 15 minutes |
| Rate limit exceeded | Slack error in logs | Investigate pipeline trigger frequency | 2 hours |
| Action version deprecated | GitHub Dependabot alert | Update to latest version | 1 week |

### 9.3 Cost Analysis

**GitHub Actions Cost**: $0 (included in free tier for public repos)
**Slack Cost**: $0 (Incoming Webhooks free on all plans)
**Infrastructure Cost**: $0 (no additional services)

**Total Cost**: $0/month

---

## 10. Future Enhancements

### 10.1 Priority 1 (Next Quarter)

**Conditional Notifications**:
- `@channel` mention for master branch failures
- Individual `@username` mention for PR failures
- Separate channel for deployment failures

**Enhanced Context**:
- Test failure summary (which tests failed)
- Code coverage delta (if coverage decreased)
- Time to failure (how quickly pipeline failed)

### 10.2 Priority 2 (Future)

**Interactive Features**:
- "Retry Pipeline" button (triggers re-run)
- "Assign to Me" button (assigns GitHub issue)
- Thread replies with failure analysis

**Analytics**:
- Dashboard showing failure trends
- MTTR (Mean Time To Resolution) tracking
- Most frequent failure stages

**Advanced Routing**:
- Route notifications based on changed files (e.g., docs changes → #docs)
- Escalation after N consecutive failures
- Quiet hours (no notifications 10pm-8am)

---

## 11. Alternative Architectures Considered (ADR-002)

### Alternative 1: AWS Lambda + API Gateway

**Architecture**:
- GitHub webhook triggers API Gateway
- Lambda function formats message
- Lambda posts to Slack

**Pros**:
- Full control over notification logic
- Can add complex routing/filtering
- Can integrate with other AWS services

**Cons**:
- Infrastructure overhead (Lambda, API Gateway, IAM roles)
- Cost ($0.20 per 1M requests + Lambda compute)
- Maintenance burden (code updates, security patches)
- Violates NFR-3 (minimal maintenance)

**Decision**: REJECTED (over-engineering, violates constraints)

---

### Alternative 2: GitHub App with Slack Bot

**Architecture**:
- GitHub App installed on repository
- Slack Bot Token (not webhook)
- Full bidirectional integration

**Pros**:
- Richer Slack features (buttons, modals, threads)
- Can query GitHub API from Slack
- Interactive workflows

**Cons**:
- Complex setup (OAuth, bot permissions)
- Higher maintenance (app updates)
- More secrets to manage (bot token)
- Violates simplicity principle

**Decision**: REJECTED (complexity not justified for notification use case)

---

### Alternative 3: Slack Email Integration

**Architecture**:
- GitHub sends email on failure
- Slack email integration posts to channel

**Pros**:
- No code changes needed
- Zero configuration in GitHub Actions

**Cons**:
- Poor formatting (plain text email)
- No rich context (buttons, links)
- Slower delivery (email latency)
- Less reliable (email spam filters)

**Decision**: REJECTED (poor user experience, unreliable)

---

## 12. Risk Assessment

| Risk | Probability | Impact | Mitigation | Owner |
|------|-------------|--------|------------|-------|
| Webhook URL leaked | Low | Medium | Quarterly rotation, instant revocation | DevOps |
| slackapi action deprecated | Low | Low | Pin version, monitor for updates | DevOps |
| Slack API outage | Very Low | Low | GitHub UI still shows failure | N/A |
| Rate limit exceeded | Very Low | Low | Slack limits are generous (600/min) | DevOps |
| Notification missed | Very Low | Medium | GitHub Actions UI is primary visibility | DevOps |

---

## 13. Success Metrics

| Metric | Target | Measurement Method |
|--------|--------|-------------------|
| Notification delivery rate | > 99.5% | Slack audit logs vs GitHub Actions failures |
| Notification latency | < 30 seconds | Timestamp diff (GitHub failure → Slack post) |
| False negatives (missed notifications) | 0 per month | Manual audit |
| Secret exposure incidents | 0 per year | GitHub security audit |
| Developer satisfaction | > 4.5/5 | Quarterly survey |

---

## 14. Handoff Package for DevOps Agent

### Required Artifacts
- ✅ Architecture document (this file)
- ✅ Implementation YAML snippet (Section 7.1)
- ✅ Slack webhook creation guide (Section 7.2)
- ✅ GitHub Secrets configuration guide (Section 7.2)
- ✅ Testing checklist (Section 8.1)
- ✅ Validation criteria (Section 8.2)

### Implementation Steps for DevOps Agent

1. **Create Slack Incoming Webhook** (Section 7.2, Step 1)
2. **Store Webhook URL in GitHub Secrets** (Section 7.2, Step 2)
3. **Add notify-slack job to ci-cd.yml** (Section 7.1)
4. **Commit and push changes** (conventional commit message)
5. **Trigger test failure** (Section 8.1, Test 1)
6. **Verify notification received** (Section 8.2)
7. **Document webhook URL rotation procedure** (Section 9.2)

### Configuration Requirements

**GitHub Secrets**:
- `SLACK_WEBHOOK_URL`: Incoming webhook URL from Slack

**Slack Workspace**:
- Channel: `#engineering-alerts` (must exist)
- App: "GitHub CI/CD Alerts" (created via api.slack.com)

**Permissions**:
- Repository admin access (to create GitHub Secrets)
- Slack workspace admin access (to create incoming webhook)

---

## 15. Compliance and Security Validation

### Security Checklist
- ✅ Webhook URL stored in GitHub Secrets (encrypted at rest)
- ✅ Webhook URL never logged (GitHub automatic sanitization)
- ✅ Webhook scoped to single channel (principle of least privilege)
- ✅ No Bot Token used (reduces attack surface)
- ✅ Quarterly secret rotation procedure documented
- ✅ Audit logging enabled (GitHub + Slack)

### Compliance Considerations
- **GDPR**: No personal data transmitted (only commit author name, publicly available)
- **SOC 2**: Audit logs enable compliance reporting
- **ISO 27001**: Secret management follows best practices

---

## Appendix A: Slack Webhook URL Format

**Structure**:
```
https://hooks.slack.com/services/{WORKSPACE_ID}/{CHANNEL_ID}/{SECRET_TOKEN}

Example:
https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXX
```

**Security Properties**:
- Workspace ID: Identifies Slack workspace
- Channel ID: Identifies target channel
- Secret Token: Cryptographically random (24 characters)
- Total entropy: ~144 bits (collision-resistant)

**Regeneration Procedure**:
1. Navigate to: https://api.slack.com/apps
2. Select app: "GitHub CI/CD Alerts"
3. Click "Incoming Webhooks"
4. Delete existing webhook
5. Click "Add New Webhook to Workspace"
6. Select same channel
7. Copy new webhook URL
8. Update GitHub Secret immediately
9. Verify notification works
10. Document change in changelog

---

## Appendix B: GitHub Actions Context Variables

**Available Variables**:

| Variable | Example Value | Description |
|----------|---------------|-------------|
| `github.repository` | `nWave-ai/nwave-dev` | Full repository name |
| `github.ref` | `refs/heads/master` | Full Git ref |
| `github.ref_name` | `master` | Branch or tag name |
| `github.sha` | `a1b2c3d4e5f6...` | Commit SHA (full) |
| `github.actor` | `Alessandro` | User who triggered workflow |
| `github.workflow` | `CI/CD Pipeline` | Workflow name |
| `github.job` | `test` | Current job name |
| `github.run_id` | `1234567890` | Unique run ID |
| `github.event_name` | `push` | Trigger event type |
| `github.event.head_commit.message` | `feat(agents): new feature` | Commit message |
| `github.server_url` | `https://github.com` | GitHub server URL |

**Reference**: https://docs.github.com/en/actions/learn-github-actions/contexts#github-context

---

## Appendix C: Slack Block Kit Reference

**Common Block Types**:

**Header Block** (large title):
```json
{
  "type": "header",
  "text": {
    "type": "plain_text",
    "text": "🚨 Alert Title"
  }
}
```

**Section Block** (structured fields):
```json
{
  "type": "section",
  "fields": [
    {
      "type": "mrkdwn",
      "text": "*Field Name:*\nField Value"
    }
  ]
}
```

**Actions Block** (buttons):
```json
{
  "type": "actions",
  "elements": [
    {
      "type": "button",
      "text": {
        "type": "plain_text",
        "text": "Button Text"
      },
      "url": "https://example.com",
      "style": "danger"
    }
  ]
}
```

**Context Block** (metadata footer):
```json
{
  "type": "context",
  "elements": [
    {
      "type": "mrkdwn",
      "text": "⏰ Timestamp or metadata"
    }
  ]
}
```

**Interactive Builder**: https://app.slack.com/block-kit-builder

---

## Document Metadata

**Change Log**:

| Version | Date | Author | Changes |
|---------|------|--------|---------|
| 1.0 | 2026-01-31 | Morgan (Solution Architect) | Initial architecture design |

**Review Status**:
- Architecture Review: PENDING
- Security Review: PENDING
- DevOps Review: PENDING

**Approval**:
- Solution Architect: Morgan ✅
- Technical Lead: PENDING
- Security Lead: PENDING

---

## References

1. GitHub Actions Documentation: https://docs.github.com/en/actions
2. slackapi/slack-github-action: https://github.com/slackapi/slack-github-action
3. Slack Incoming Webhooks: https://api.slack.com/messaging/webhooks
4. Slack Block Kit: https://api.slack.com/block-kit
5. GitHub Secrets Security: https://docs.github.com/en/actions/security-guides/encrypted-secrets
6. OWASP Secret Management: https://owasp.org/www-community/vulnerabilities/Sensitive_Data_Exposure

---

**END OF ARCHITECTURE DOCUMENT**
