Detection-as-Code CI/CD Workflow Overview

Integrating Detection-as-Code (DaC) into a CI/CD pipeline enables scalable, testable, and automated management of your Sigma rules or platform-specific detections (e.g., KQL, SPL, Lucene). Below is a step-by-step guide to CI/CD integration tailored for platforms like Microsoft Sentinel, Splunk, Elastic, etc.

Detection-as-Code CI/CD Workflow Overview

Git Repo (Sigma Rules)
   ↓
Pull Request → Pre-Commit Validation
   ↓
CI Pipeline (Lint, Translate, Test)
   ↓
CD Pipeline (Deploy to SIEM via API or GitOps)

Step-by-Step Integration Plan

1. Repository Structure

Use a standardized Git repo for rule management:

detection-rules/
├── sigma/
│   ├── windows/
│   ├── cloud/
│   ├── endpoint/
├── platform-translations/
│   ├── sentinel-kql/
│   ├── splunk-spl/
│   └── elastic-lucene/
├── tests/
│   └── sample-logs/
├── ci/
│   └── test-pipeline.yaml
└── .gitlab-ci.yml / .github/workflows/ci.yml

2. Rule Validation (Pre-Commit Hook or CI Job)

Use sigma-cli or sigmac:

sigma-cli lint ./sigma/

GitHub Actions Job:

- name: Validate Sigma Rules
  run: |
    pip install sigma-cli
    sigma-cli lint ./sigma/

3. Translate Sigma to SIEM-Specific Language

Example: Translate to Sentinel (KQL)

sigma-cli translate ./sigma/windows/ -t sentinel -o ./platform-translations/sentinel-kql/

Example: Translate to Splunk (SPL)

sigma-cli translate ./sigma/windows/ -t splunk -o ./platform-translations/splunk-spl/

4. Rule Testing (Unit Testing with Sample Data)

• Simulate detection hits with sample logs (EVTX, JSON).
• Use Sigma test cases or build your own YAML + sample log pair:
• rule.yml + test-log.json

Tool suggestions:

• Sigma CLI test framework
• Custom Python-based test runners with log replay.

5. CI/CD Integration (Deployment)

Microsoft Sentinel

• Use Azure DevOps Pipelines + ARM/Bicep templates or REST API:

Deploy KQL analytics rules using:

• az sentinel alert-rule create --workspace-name "SOC" --rule-name "HighRiskLogin" --rule-file "rule.json"

Splunk

• Use GitOps with the etc/apps/search/local/ directory and deploy via:
• Splunk Deployment Server
• Ansible, Terraform, or Jenkins CI
• REST API to push saved searches

Elastic

• Use Elastic API or Fleet integration: Push rules to Kibana Detection Engine via POST _security/role or integration package.

6. Continuous Monitoring & Feedback

• Track false positive rates, detection coverage, and rule usage.

Feed feedback into:

• Rule suppression logic
• Telemetry gaps
• AI/ML enrichment triggers

Tools to Consider

Tool Use sigma-cli Translate/lint/test Sigma rules.

git-secrets, pre-commit Ensure YAML quality.

Jenkins/GitHub Actions/GitLab CI Automate the pipeline.

Terraform/Ansible Deploy rules to SIEM.

Pytest + Sample Logs Custom rule testing framework