Docker Health Monitor

Monitor Docker container health: running status, CPU/memory usage, restart counts, and available image updates. Use when a user requests Docker health checks, container monitoring, resource usage reports, restart tracking, or image freshness audits — run targeted checks or a full health report.

Script

scripts/docker-health.sh — the single entry point for all checks.

The script is self-contained and works on any system with Docker installed. It auto-detects the Docker socket availability and gracefully handles permission issues.

Quick Start

Run a full health report:

bash

bash scripts/docker-health.sh --all

Or with no arguments (same as --all):

bash

bash scripts/docker-health.sh

Individual Checks

Run any single check by name:

Command	What it checks
--status	Lists all containers with their current status (running, stopped, paused, etc.)
--resources	Shows CPU and memory usage per container via docker stats
--restarts	Flags containers that have restarted more than 3 times
--images	Checks for available image updates by comparing local image digests with registry
--full	Runs all checks in sequence (same as --all)

Example:

bash

bash scripts/docker-health.sh --status --restarts

Full Audit Workflow

1. Run bash scripts/docker-health.sh --all
2. The script outputs a formatted report to stdout
3. Key sections: container status summary, resource usage table, restart warnings, image update availability

Common Findings & Recommendations

• High restart counts (>3): Indicates container instability — check logs with docker logs <container> and review healthcheck configuration
• High memory usage: Consider setting --memory limits in the container's run/stack config; check for memory leaks in the application
• High CPU usage: Investigate application processes; consider CPU limits or horizontal scaling
• Outdated images: Run docker pull to update images; consider automated update workflows (watchtower, renovate-bot)
• Exited containers: Check exit codes — 0 means intentional stop, non-zero indicates errors

Notes

• Requires access to the Docker socket (/var/run/docker.sock) — run as root or add user to the docker group
• --resources runs docker stats in non-streaming mode (one-shot per container) for quick snapshots
• --images checks are advisory — uses docker inspect for image digests and checks for newer versions; requires network access to the registry
• Works with both local Docker and remote Docker contexts (DOCKER_HOST env var)