Maintaining full-stack visibility across distributed endpoints often degrades into an operational nightmare of bloated agents, complex SaaS billing models, and fragmented monitoring tools. When systems fail at 3 AM, engineers need instant actionable insights across their entire topology, from raw server resource utilization down to API protocol layer latency.

CheckCle approaches this challenge by delivering an all-in-one open-source monitoring solution designed for seamless, real-time observability across applications, services, and core infrastructure. Released under the permissive MIT License, CheckCle packs endpoint probing, server telemetry, SSL validation, public status pages, and multi-channel alerting into a streamlined, containerized footprint.

Comprehensive Monitoring Across Every Infrastructure Layer

Modern systems architecture demands more than simple ICMP ping checks. CheckCle breaks down system visibility into targeted layers, giving sysadmins, developers, and DevOps teams complete operational control over every service dependency.

Protocol and API Service Probing

At the uptime layer, CheckCle actively monitors critical transport and application protocols. It provides detailed tracking of response times, availability history, and subtle performance degradations before they escalate into outages. Supported protocols and service checks include:

• Network & Web Protocols: HTTP, DNS, and Ping endpoints.
• TCP Services: Custom TCP port checking and specialized application protocols, including FTP, SMTP, and HTTP API endpoints.
• Incident State Engine: Tracks real-time states across four distinct statuses: UP, DOWN, WARNING, and PAUSE.
• Distributed Regional Monitoring: Executes probes across geographical regions to capture true localized performance bottlenecks and network routing anomalies.

Automated SSL & Domain Lifecycle Management

Domain registration lapses and expired TLS certificates remain primary culprits of unnecessary system downtime. CheckCle eliminates these single points of failure by embedding native domain and SSL lifecycle tracking directly into the monitoring engine. It tracks:

• Domain registrar status and expiration dates.
• SSL certificate issuer validation and raw expiration dates.
• Remaining operational days countdowns with automated notification triggering.
• Historical record of last notification timestamps to prevent alert fatigue.

Operating System Metrics via One-Line Agent

Beyond remote synthetic testing, CheckCle captures deep system-level telemetry directly from bare-metal servers, virtual machines, and edge devices. Deploying a lightweight one-line installation agent script yields real-time host metrics across:

• CPU utilization and load spikes.
• RAM consumption and threshold limits.
• Disk capacity and localized partition usage.
• Network interface ingress and egress activity.

The agent natively supports major Linux distributions, including Debian, Ubuntu, CentOS, and Red Hat Enterprise Linux. Windows host monitoring is also available in Beta.

Feature Category	Capabilities & Supported Protocol/Targets
Uptime Protocols	HTTP, DNS, Ping, TCP, FTP, SMTP, API Endpoints
Infrastructure OS Support	Linux (Debian, Ubuntu, CentOS, Red Hat), Windows (Beta)
System Telemetry	CPU, RAM, Disk Usage, Network Activity
Certificate Engine	SSL Issuer, Expiration Date, Days Remaining, Domain Status
Supported Hardware	x86_64 (amd64), arm64 (Raspberry Pi 3/4/5 64-bit, Apple Silicon)
Alert Channels	Email, Telegram, Discord, Slack, Matrix

Deploying CheckCle via Docker Orchestration

CheckCle supports cross-platform execution on standard x86_64 (amd64) hardware as well as 64-bit arm64 environments, including Raspberry Pi 3, 4, 5, and Apple Silicon devices. Running the entire management stack requires minimal host dependencies.

Recommended Docker Compose Setup

Deploying CheckCle with docker-compose allows persistent data storage mapped directly to your host directory at /opt/pb_data. To handle high concurrent connections during aggressive probe cycles, configure host system resource limits directly inside the configuration file.

yaml
version: '3.9'
services:
  checkcle:
    image: operacle/checkcle:latest
    container_name: checkcle
    restart: unless-stopped
    ports:
      - "8090:8090" # Web Application Port
    volumes:
      - /opt/pb_data:/mnt/pb_data # Host directory mapped to container path
    ulimits:
      nofile:
        soft: 4096
        hard: 8192

Direct CLI Deployment with docker run

Alternatively, execute a single Docker command to spin up the container environment immediately:

bash
docker run -d \
  --name checkcle \
  --restart unless-stopped \
  -p 8090:8090 \
  -v /opt/pb_data:/mnt/pb_data \
  --ulimit nofile=4096:8192 \
  operacle/checkcle:latest

Once running, navigate your web browser to http://0.0.0.0:8090. The default administrative access credentials are:

• Default Administrative User: admin@example.com
• Default Password: Admin123456

Incident Management, Public Status Pages, and Alerting

Detecting an issue is only half the battle. Delivering context-rich alerts to on-call engineers while communicating service state to external stakeholders completes the operational loop.

Incident Management & Maintenance Scheduling

CheckCle features built-in maintenance scheduling, allowing engineering teams to suppress noise during planned deployment windows. Detailed incident history tracking records root-cause events and precise operational timeline logs.

Operational Public Status Pages

Building trust with end-users requires direct transparency. CheckCle enables users to generate clean operational status pages. These public-facing dashboards showcase current system health and historical uptime metrics without exposing internal administrative controls.

Native Notification Channel Integration

Alert routing engine rules dispatch instant notifications across modern communication channels. Teams can configure notification templates, custom channel logic, and data retention policies inside the built-in settings panel. Out-of-the-box integrations support:

• Telegram
• Discord
• Slack
• Matrix
• Standard Email SMTP

Administrative Controls and Open-Source Ecosystem

The core administrative console provides detailed platform configuration options:

• User Management: Role access and administrative access control.
• Data Retention: Customizable historical metrics purging schedules.
• Localization & Visual UI: Multi-language support with native Dark Mode and Light Mode switching.
• Alert Customization: Configurable alert templates and notification rule sets.

Community and Infrastructure Partnership Model

CheckCle is developed as a community-first, free open-source project under the MIT License. In lieu of traditional financial sponsorships, the project operates on ecosystem partnerships. Organizations looking to support CheckCle contribute infrastructure resources, such as high-performance cloud servers, domain management, or hosting credits. Documentation services are sponsored directly by GitBook.

Engineers interested in contributing code enhancements, bug fixes, or documentation updates can join the project community on Discord, follow updates on X (@asqrm_io), or inspect the codebase directly on GitHub.

References

• https://github.com/operacle/checkcle