# Docker Ops

> Docker container operations and debugging

- Skill: `agenticdevops/docker-ops` (Agent Skill)
- Install (CLI): `npx skillmds@latest add agenticdevops/docker-ops`
- Raw SKILL.md: https://api.skillmd.com/api/skills/agenticdevops/docker-ops/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: agenticdevops (https://skillmd.com/u/agenticdevops)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/agenticdevops/docker-ops

---


# Docker Operations

Quick reference for Docker container management and debugging.

## When to Use This Skill

Use this skill when:
- Managing Docker containers
- Debugging container issues
- Checking container logs
- Cleaning up Docker resources
- Inspecting container state

## Quick Status Commands

### List Containers

```bash
# Running containers
docker ps

# All containers (including stopped)
docker ps -a

# With size info
docker ps -s

# Custom format
docker ps --format "table {{.Names}}\t{{.Status}}\t{{.Ports}}"
```

### Container Logs

```bash
# View logs
docker logs <container>

# Follow logs (live)
docker logs -f <container>

# Last N lines
docker logs --tail 100 <container>

# With timestamps
docker logs -t <container>

# Since time
docker logs --since 1h <container>
```

### Resource Usage

```bash
# Live stats for all containers
docker stats

# One-time stats (no stream)
docker stats --no-stream

# Specific container
docker stats <container>
```

## Container Management

### Start/Stop/Restart

```bash
# Start stopped container
docker start <container>

# Stop running container
docker stop <container>

# Restart container
docker restart <container>

# Kill (force stop)
docker kill <container>
```

### Execute Commands

```bash
# Run command in container
docker exec <container> <command>

# Interactive shell
docker exec -it <container> /bin/sh
docker exec -it <container> /bin/bash

# As root
docker exec -u root -it <container> /bin/sh
```

### Inspect Container

```bash
# Full inspect output
docker inspect <container>

# Get specific field
docker inspect -f '{{.State.Status}}' <container>
docker inspect -f '{{.NetworkSettings.IPAddress}}' <container>
docker inspect -f '{{json .Config.Env}}' <container>
```

## Image Management

### List Images

```bash
# All images
docker images

# With digests
docker images --digests

# Dangling images only
docker images -f "dangling=true"
```

### Pull/Push

```bash
# Pull image
docker pull <image>:<tag>

# Push image
docker push <image>:<tag>
```

## Cleanup Commands

### Safe Cleanup

```bash
# Remove stopped containers
docker container prune -f

# Remove unused images
docker image prune -f

# Remove unused volumes
docker volume prune -f

# Remove unused networks
docker network prune -f

# Full system cleanup (safe - only unused)
docker system prune -f
```

### Check Disk Usage

```bash
# Docker disk usage summary
docker system df

# Detailed breakdown
docker system df -v
```

## Debugging

### Container Not Starting

```bash
# Check container state
docker inspect -f '{{.State.Status}}' <container>
docker inspect -f '{{.State.Error}}' <container>

# Check logs
docker logs <container>

# Check events
docker events --since 1h --filter container=<container>
```

### Network Issues

```bash
# List networks
docker network ls

# Inspect network
docker network inspect <network>

# Check container network
docker inspect -f '{{json .NetworkSettings.Networks}}' <container>

# Test connectivity from container
docker exec <container> ping -c 3 <host>
docker exec <container> curl -v <url>
```

### Resource Issues

```bash
# Check container resource limits
docker inspect -f '{{.HostConfig.Memory}}' <container>
docker inspect -f '{{.HostConfig.CpuShares}}' <container>

# Live resource usage
docker stats <container> --no-stream
```

## Common Patterns

### Run One-Off Command

```bash
# Run and remove after
docker run --rm <image> <command>

# Example: check version
docker run --rm alpine cat /etc/alpine-release
```

### Copy Files

```bash
# Copy from container to host
docker cp <container>:/path/to/file ./local/path

# Copy from host to container
docker cp ./local/file <container>:/path/in/container
```

### View Container Processes

```bash
# Processes in container
docker top <container>
```

## Quick Troubleshooting

| Symptom | Check | Fix |
|---------|-------|-----|
| Container exits immediately | `docker logs <container>` | Fix application error |
| Can't connect to container | `docker inspect` network | Check port mapping |
| Container slow | `docker stats` | Increase resources |
| Disk full | `docker system df` | `docker system prune` |
| Image pull fails | Network/auth | Check registry access |

## Related Skills

- **k8s-debug**: For Kubernetes container debugging
- **log-analysis**: For log pattern analysis