Docker Syntax Cli Containers

docker-syntax-cli-containers

Quick Reference

Container Lifecycle Overview

| Command | Purpose | Key Flags | |---------|---------|-----------| | docker run | Create and start container | -d, -it, --rm, --name, -p, -v | | docker create | Create without starting | Same as run | | docker start | Start stopped container | -a (attach), -i (interactive) | | docker stop | Graceful stop (SIGTERM) | -t (grace period, default 10s) | | docker restart | Stop then start | -t (grace period) | | docker kill | Immediate signal | -s (signal, default SIGKILL) | | docker rm | Remove container | -f (force), -v (volumes) | | docker container prune | Remove all stopped | --filter | | docker exec | Run command in container | -it, -u, -w, -e | | docker logs | Read container output | -f, --tail, --since | | docker inspect | Container metadata | --format (Go templates) | | docker ps | List containers | -a, --filter, --format | | docker stats | Live resource usage | --no-stream, --format | | docker top | Container processes | Accepts ps options | | docker events | Real-time daemon events | --filter, --since | | docker cp | Copy files in/out | -a (archive mode) | | docker diff | Filesystem changes | A=Added, C=Changed, D=Deleted | | docker rename | Rename container | — | | docker update | Change resource limits | --memory, --cpus, --restart | | docker pause | Freeze container | — | | docker unpause | Resume container | — | | docker wait | Block until exit | Returns exit code | | docker port | Show port mappings | — | | docker attach | Attach to STDIN/STDOUT | --detach-keys |

docker run Flag Categories

| Category | Key Flags | Details | |----------|-----------|---------| | Execution | -d, -it, --rm, --name, --init | [references/commands.md#execution](references/commands.md) | | Ports & Network | -p, --network, --hostname, --dns | [references/commands.md#ports--network](references/commands.md) | | Storage | -v, --mount, --read-only, --tmpfs | [references/commands.md#storage](references/commands.md) | | Environment | -e, --env-file, -w, --entrypoint, -u | [references/commands.md#environment](references/commands.md) | | Resources | -m, --cpus, --pids-limit, --ulimit | [references/commands.md#resources](references/commands.md) | | Security | --cap-add, --cap-drop, --security-opt, --read-only | [references/commands.md#security](references/commands.md) | | Health | --health-cmd, --health-interval, --health-retries | [references/commands.md#health](references/commands.md) | | Restart | --restart no\|always\|unless-stopped\|on-failure[:N] | [references/commands.md#restart](references/commands.md) | | Logging | --log-driver, --log-opt | [references/commands.md#logging](references/commands.md) | | Pull & Platform | --pull, --platform | [references/commands.md#pull--platform](references/commands.md) |

Critical Warnings

NEVER use --privileged in production -- it grants the container full host access. ALWAYS use specific --cap-add flags for the exact capabilities needed.

NEVER run containers as root unless technically required. ALWAYS use -u 1000:1000 or define USER in the Dockerfile.

NEVER use --link for container communication -- it is legacy. ALWAYS use user-defined bridge networks with --network.

NEVER use docker exec with chained commands directly -- the shell interprets && on the host. ALWAYS wrap in sh -c "cmd1 && cmd2".

NEVER run docker rm -f on production databases without confirming backups. ALWAYS stop gracefully with docker stop first.

ALWAYS use --rm for one-off containers (tests, migrations, debug shells) to prevent stopped container accumulation.

ALWAYS set --init when running applications that do not handle signals or reap zombie processes (e.g., shell scripts, Node.js without signal handlers).

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docker ps -- Filter Cheat Sheet

Filter Options

| Filter | Match Type | Example | |--------|-----------|---------| | name | Substring | --filter name=web | | status | Exact | --filter status=running | | ancestor | Image name/tag/ID | --filter ancestor=nginx:latest | | label | Key or key=value | --filter label=app=web | | exited | Exit code (with -a) | --filter exited=0 | | health | Health status | --filter health=healthy | | network | Network name/ID | --filter network=mynet | | volume | Volume name/mount | --filter volume=mydata | | publish | Published port | --filter publish=80/tcp | | before/since | Relative to container | --filter before=myapp |

Status Values

created | restarting | running | removing | paused | exited | dead

Format Placeholders

| Placeholder | Output | |-------------|--------| | {{.ID}} | Container ID | | {{.Names}} | Container name | | {{.Image}} | Image name | | {{.Status}} | Detailed status with health | | {{.State}} | State (running/exited) | | {{.Ports}} | Port mappings | | {{.RunningFor}} | Uptime | | {{.Size}} | Disk usage (with -s) | | {{.Label "key"}} | Specific label value | | {{.Networks}} | Network names | | {{.Mounts}} | Volume names |

# Useful one-liners
docker ps --format "table {{.Names}}\t{{.Status}}\t{{.Ports}}"
docker ps -a --filter status=exited --format "{{.Names}}: exited {{.Status}}"
docker ps -q --filter status=exited | xargs docker rm
docker ps --format json

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docker inspect -- Common Format Strings

Container State

docker inspect --format='{{.State.Status}}' CONTAINER
docker inspect --format='{{.State.Running}}' CONTAINER
docker inspect --format='{{.State.ExitCode}}' CONTAINER
docker inspect --format='{{.State.Pid}}' CONTAINER
docker inspect --format='{{.State.StartedAt}}' CONTAINER

Network Information

# IP address
docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' CONTAINER

# Port bindings
docker inspect --format='{{range $p, $conf := .NetworkSettings.Ports}}{{$p}} -> {{(index $conf 0).HostPort}}{{end}}' CONTAINER

# Network name
docker inspect --format='{{range $k, $v := .NetworkSettings.Networks}}{{$k}}{{end}}' CONTAINER

Configuration

docker inspect --format='{{.Config.Image}}' CONTAINER
docker inspect --format='{{json .Config.Cmd}}' CONTAINER
docker inspect --format='{{range .Config.Env}}{{println .}}{{end}}' CONTAINER
docker inspect --format='{{json .Config.Labels}}' CONTAINER
docker inspect --format='{{index .Config.Labels "com.example.version"}}' CONTAINER

Mounts

docker inspect --format='{{range .Mounts}}{{.Source}} -> {{.Destination}}{{println}}{{end}}' CONTAINER
docker inspect --format='{{json .Mounts}}' CONTAINER

Size

docker inspect --size -f '{{.SizeRootFs}}' CONTAINER
docker inspect --size -f '{{.SizeRw}}' CONTAINER

Health Check

docker inspect --format='{{.State.Health.Status}}' CONTAINER
docker inspect --format='{{json .State.Health}}' CONTAINER

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Decision Trees

Which Run Mode?

Need interactive shell?
├── YES → docker run -it --rm IMAGE bash
└── NO → Need background daemon?
    ├── YES → docker run -d --name NAME IMAGE
    └── NO → One-off command?
        ├── YES → docker run --rm IMAGE COMMAND
        └── NO → docker create + docker start

Which Stop Method?

Need graceful shutdown?
├── YES → docker stop [-t SECONDS] CONTAINER
│         (sends SIGTERM, waits grace period, then SIGKILL)
└── NO → Need immediate termination?
    ├── YES → docker kill CONTAINER
    └── NO → Need to send specific signal?
        └── YES → docker kill -s SIGNAL CONTAINER

Exec or Attach?

Need to run a NEW command in running container?
├── YES → docker exec -it CONTAINER COMMAND
└── NO → Need to connect to the MAIN process?
    ├── YES → docker attach CONTAINER
    │         (Ctrl+P, Ctrl+Q to detach without stopping)
    └── NO → Just need logs?
        └── YES → docker logs -f CONTAINER

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Common Patterns

Production Container Launch

docker run -d \
  --name myapp \
  --restart unless-stopped \
  --init \
  -u 1000:1000 \
  --read-only \
  --tmpfs /tmp \
  --cap-drop ALL \
  --security-opt no-new-privileges=true \
  -m 512m --cpus 1.5 --pids-limit 200 \
  -p 127.0.0.1:8080:8080 \
  --network mynet \
  --mount source=appdata,target=/data \
  -e NODE_ENV=production \
  --log-opt max-size=10m --log-opt max-file=3 \
  --health-cmd='curl -f http://localhost:8080/health || exit 1' \
  --health-interval=30s \
  myapp:v1.2.3

Debug a Running Container

# Shell into container
docker exec -it myapp sh

# Check processes
docker top myapp

# Stream logs
docker logs -f --tail 100 myapp

# Resource usage
docker stats myapp --no-stream

# Filesystem changes
docker diff myapp

# Full metadata
docker inspect myapp | jq '.[0].State'

Container Cleanup

# Remove specific stopped container and its anonymous volumes
docker rm -v myapp

# Remove ALL stopped containers
docker container prune -f

# Remove containers older than 24 hours
docker container prune -f --filter "until=24h"

# Force remove running container (emergency only)
docker rm -f myapp

Copy Files

# Extract logs from container
docker cp myapp:/var/log/app.log ./app.log

# Inject config into running container
docker cp ./config.yml myapp:/app/config.yml

# Archive mode (preserves UID/GID)
docker cp -a myapp:/app/data ./backup/

Update Running Container Resources

docker update --memory 1g --cpus 2 myapp
docker update --restart always myapp
docker update --pids-limit 300 myapp

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Reference Links

• [references/commands.md](references/commands.md) -- Complete flag reference for all container commands
• [references/examples.md](references/examples.md) -- Common container management workflows
• [references/anti-patterns.md](references/anti-patterns.md) -- CLI misuse patterns and corrections

Official Sources

• https://docs.docker.com/reference/cli/docker/container/
• https://docs.docker.com/reference/cli/docker/container/run/
• https://docs.docker.com/reference/cli/docker/container/exec/
• https://docs.docker.com/reference/cli/docker/container/logs/
• https://docs.docker.com/reference/cli/docker/container/ls/
• https://docs.docker.com/reference/cli/docker/inspect/

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Impertio-Studio
• Source: Impertio-Studio/Docker-Claude-Skill-Package
• License: MIT

Install and usage instructions live in the source repository linked above.