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Subroto Saha
Subroto Saha

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🛡️ Sentinel: The Safety-First Docker Deployment Controller

Stop blindly updating. Start orchestrating. Sentinel is the mission-critical controller that bridges the gap between manual Docker management and risky "black-box" automation.


🚀 The Core Value Proposition

In modern infrastructure, automation without governance is a liability. While tools like Watchtower revolutionized the "auto-pull" concept, they often lack the safeguards required for production environments.

Sentinel was built for the DevOps engineer who needs the efficiency of automated updates but cannot afford 3:00 AM downtime. It brings Manual Approval Gates, Health-Check Driven Rollbacks, and API-First Orchestration to standard Docker environments.


💎 The Three Pillars of Sentinel

1. Uncompromising Safety (The "Self-Healing" Edge)

Sentinel doesn't just "recreate" containers; it protects them.

  • Health-Gated Rollbacks: If a new image fails its internal health check, Sentinel detects the failure in real-time and restores the previous stable image automatically.
  • Configuration Preservation: Every network setting, environment variable, and host mount is meticulously cloned, ensuring your "updated" container behaves exactly like the one it replaced.

2. Absolute Control (The "Human-in-the-Loop" Model)

Automation should serve the operator, not replace them.

  • Manual Approval Gates: Hold detected updates in a "Pending" state. Use the Sentinel API to review, approve, or reject changes before they hit production.
  • Cron-Precision Scheduling: Restrict update cycles to specific maintenance windows using standard Cron syntax. Stop updates from disrupting peak traffic.

3. Total Visibility (The "Observability" Suite)

Sentinel transforms your deployment logs into actionable intelligence.

  • Multi-Channel Notifications: Native integrations for Slack, Microsoft Teams, and Email ensure your team is always informed of successful rollouts or critical failures.
  • Prometheus Metrics: Export real-time telemetry on update velocity, failure rates, and pending approvals directly into your Grafana dashboards.

🛠️ Feature Deep-Dive

Feature Description Business Benefit
Compose Awareness Deep integration with Docker Compose stacks. Manage entire services as a single unit.
SemVer Policies Restrict updates to patch or minor releases. Eliminate breaking major-version jumps.
API-First Design Fully documented Bearer-protected API. Integrate updates into your custom CI/CD pipelines.
Pre/Post Hooks Run custom scripts before or after updates. Trigger smoke tests or clear caches automatically.
Private Auth Seamless support for GHCR, Docker Hub, and private registries. Secure management of proprietary code.

📊 Sentinel vs. The Competition

Capability Standard Auto-Updaters Sentinel
Image Update Detection
Scheduled Polling
Manual Approval Workflow YES
Automatic Rollback YES
Health Check Gating YES
Compose Stack Control YES
Prometheus Telemetry YES

🚀 Getting Started in 60 Seconds

Deploy Sentinel as a sidecar to your Docker daemon and take control of your fleet today.


yaml
services:
  sentinel:
    image: isubroto/sentinel:latest
    container_name: sentinel
    environment:
      SENTINEL_WATCH_ALL: "true"
      SENTINEL_ROLLBACK: "true"
      SENTINEL_APPROVAL: "true"
      SENTINEL_API_ENABLED: "true"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./data:/app/data

this is my linked in post but linked in not supported markdown then?
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