# Docker Syntax Cli Images

> >

- **Type:** Skill
- **Install:** `agentstack add skill-impertio-studio-docker-claude-skill-package-docker-syntax-cli-images`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Impertio-Studio](https://agentstack.voostack.com/s/impertio-studio)
- **Installs:** 0
- **Category:** [Cloud & Infrastructure](https://agentstack.voostack.com/c/cloud-infrastructure)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Impertio-Studio](https://github.com/Impertio-Studio)
- **Source:** https://github.com/Impertio-Studio/Docker-Claude-Skill-Package/tree/main/skills/source/docker-syntax/docker-syntax-cli-images

## Install

```sh
agentstack add skill-impertio-studio-docker-claude-skill-package-docker-syntax-cli-images
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# docker-syntax-cli-images

## Quick Reference

### Image Lifecycle Commands

| Command | Purpose | Example |
|---------|---------|---------|
| `docker buildx build` | Build image from Dockerfile (default builder) | `docker buildx build -t myapp:v1 .` |
| `docker pull` | Download image from registry | `docker pull nginx:1.25` |
| `docker push` | Upload image to registry | `docker push myregistry.com/myapp:v1` |
| `docker tag` | Create new tag for existing image | `docker tag myapp:v1 myregistry.com/myapp:v1` |
| `docker images` | List local images | `docker images --filter dangling=true` |
| `docker rmi` | Remove image(s) | `docker rmi nginx:old` |
| `docker image prune` | Remove unused images | `docker image prune -a -f` |
| `docker save` | Export image to tar archive | `docker save -o backup.tar myapp:v1` |
| `docker load` | Import image from tar archive | `docker load -i backup.tar` |
| `docker history` | Show image layer history | `docker history --no-trunc myapp:v1` |
| `docker manifest inspect` | Inspect multi-platform manifest | `docker manifest inspect nginx:latest` |

### System Management Commands

| Command | Purpose | Example |
|---------|---------|---------|
| `docker system df` | Show disk usage breakdown | `docker system df -v` |
| `docker system prune` | Remove all unused resources | `docker system prune -a --volumes -f` |
| `docker info` | Show system-wide information | `docker info --format '{{.ServerVersion}}'` |
| `docker version` | Show client/server versions | `docker version --format json` |
| `docker context` | Manage remote Docker hosts | `docker context use remote` |

### Critical Warnings

**NEVER** run `docker system prune -a --volumes` on production systems without first running `docker system df` -- it removes ALL unused volumes including database data.

**NEVER** use `docker build` (legacy) for new projects -- ALWAYS use `docker buildx build` which is the default BuildKit-based builder since Docker Engine 23+.

**NEVER** push images without verifying the tag -- `docker push myapp` pushes ALL tags of that repository. ALWAYS specify the exact tag: `docker push myapp:v1`.

**ALWAYS** use `--platform` when building for a different architecture -- omitting it silently builds for the host platform, causing `exec format error` at runtime on the target.

**ALWAYS** run `docker system df` before any cleanup operation to understand what is consuming disk space.

---

## Buildx Build Flag Reference

### Core Build Flags

| Flag | Description | Example |
|------|-------------|---------|
| `-f, --file` | Dockerfile path | `-f Dockerfile.prod` |
| `-t, --tag` | Tag the image (repeatable) | `-t myapp:v1 -t myapp:latest` |
| `--target` | Build specific stage | `--target build-env` |
| `--build-arg` | Build-time variable | `--build-arg NODE_ENV=prod` |
| `--no-cache` | Disable build cache entirely | `--no-cache` |
| `--pull` | Always pull base images | `--pull` |
| `--progress` | Output format: auto/plain/tty/quiet | `--progress=plain` |

### Output Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--load` | Load into local Docker images | `--load` |
| `--push` | Push to registry after build | `--push` |
| `-o, --output` | Custom output destination | `-o type=local,dest=./out` |

Output types: `docker` (local), `registry` (push), `local` (filesystem), `tar`, `oci`, `image`.

### Multi-Platform Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--platform` | Target platform(s) | `--platform linux/amd64,linux/arm64` |
| `--builder` | Use specific builder instance | `--builder mybuilder` |

**ALWAYS** use `--push` or `-o` (not `--load`) when building for multiple platforms -- `--load` only supports single-platform images.

### Cache Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--cache-from` | Import cache source | `--cache-from type=gha` |
| `--cache-to` | Export cache destination | `--cache-to type=gha,mode=max` |

Cache types: `registry`, `local`, `inline`, `gha` (GitHub Actions), `s3`, `azblob`.

### Security & Secrets Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--secret` | Expose secret to build (never baked in) | `--secret id=aws,src=$HOME/.aws/credentials` |
| `--ssh` | Expose SSH agent/keys to build | `--ssh default=$SSH_AUTH_SOCK` |

### Attestation Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--provenance` | SLSA provenance attestation | `--provenance=mode=max` |
| `--sbom` | Software Bill of Materials | `--sbom` |
| `--metadata-file` | Write build metadata as JSON | `--metadata-file meta.json` |

---

## Buildx Builder Management

```bash
# Create a new builder instance
docker buildx create --name mybuilder --use

# List all builders
docker buildx ls

# Inspect current builder
docker buildx inspect

# Switch to a builder
docker buildx use mybuilder

# Remove a builder
docker buildx rm mybuilder
```

**ALWAYS** create a dedicated builder for multi-platform builds -- the default builder does not support multi-platform output.

---

## Image Filter Cheat Sheet

### docker images --filter

| Filter | Description | Example |
|--------|-------------|---------|
| `dangling=true` | Untagged images (no repo:tag) | `docker images -f dangling=true` |
| `label=key` | Images with specific label | `docker images -f label=maintainer` |
| `label=key=value` | Images with label matching value | `docker images -f label=app=web` |
| `before=image` | Created before given image | `docker images -f before=nginx:1.24` |
| `since=image` | Created after given image | `docker images -f since=nginx:1.24` |
| `reference=pattern` | Wildcard match on repo:tag | `docker images -f reference="ngin*:lat*"` |

### Image Format Placeholders

| Placeholder | Output |
|-------------|--------|
| `{{.ID}}` | Image ID |
| `{{.Repository}}` | Repository name |
| `{{.Tag}}` | Tag |
| `{{.Digest}}` | Content digest |
| `{{.CreatedSince}}` | Time since creation |
| `{{.CreatedAt}}` | Creation timestamp |
| `{{.Size}}` | Disk size |

```bash
# Compact image list
docker images --format "table {{.Repository}}\t{{.Tag}}\t{{.Size}}"

# JSON output (one per line)
docker images --format json

# Only IDs for scripting
docker images -q

# Remove all dangling images
docker rmi $(docker images -q -f dangling=true)
```

---

## Disk Cleanup Strategy

**ALWAYS follow this order -- from safest to most aggressive:**

1. **Assess** -- `docker system df -v`
2. **Containers** -- `docker container prune -f`
3. **Dangling images** -- `docker image prune -f`
4. **All unused images** -- `docker image prune -a -f`
5. **Build cache** -- `docker builder prune -f`
6. **Volumes** -- `docker volume ls -f dangling=true` then `docker volume prune -f`
7. **Nuclear** -- `docker system prune -a --volumes -f`

### What Each Prune Removes

| Command | Removes |
|---------|---------|
| `docker container prune` | All stopped containers |
| `docker image prune` | Dangling images only |
| `docker image prune -a` | ALL unused images |
| `docker network prune` | All unused networks |
| `docker volume prune` | All unused anonymous volumes |
| `docker builder prune` | Build cache |
| `docker system prune` | Containers + networks + dangling images + build cache |
| `docker system prune -a --volumes` | All of the above + all unused images + volumes |

### Prune Filter Flags

| Flag | Description | Example |
|------|-------------|---------|
| `--filter "until=24h"` | Resources older than duration | `docker image prune -f --filter "until=24h"` |
| `--filter "label=temp"` | Resources with label | `docker system prune --filter "label=temp"` |
| `--filter "label!=keep"` | Resources without label | `docker image prune --filter "label!=keep"` |
| `-f` | Skip confirmation prompt | `docker system prune -f` |

---

## Decision Tree: Which Cleanup Command?

```
Need to free disk space?
├── Know what's using space? → docker system df -v
├── Just dangling/untagged images? → docker image prune -f
├── All unused images? → docker image prune -a -f
├── Stopped containers? → docker container prune -f
├── Build cache growing? → docker builder prune -f
├── Unused volumes? → docker volume prune -f (CHECK FIRST!)
└── Everything unused? → docker system prune -a --volumes -f (DANGEROUS on prod)
```

```
Need to transfer images offline?
├── Full image with layers + tags + history → docker save / docker load
├── Container filesystem snapshot (no metadata) → docker export / docker import
└── Multi-platform manifest → docker manifest create + push
```

```
Need multi-platform builds?
├── Single platform, local use → docker buildx build --platform linux/amd64 --load .
├── Multiple platforms, push to registry → docker buildx build --platform linux/amd64,linux/arm64 --push .
└── Need a builder first? → docker buildx create --name mp --use
```

---

## System Information Commands

### docker system df

```bash
docker system df              # Summary: images, containers, volumes, build cache
docker system df -v           # Verbose per-resource breakdown
docker system df --format "table {{.Type}}\t{{.TotalCount}}\t{{.Size}}\t{{.Reclaimable}}"
```

### docker info

```bash
docker info                                    # Full system information
docker info --format '{{.ServerVersion}}'      # Server version only
docker info --format '{{.Driver}}'             # Storage driver
docker info --format '{{json .Plugins}}'       # Available plugins
```

### docker version

```bash
docker version                                 # Client + server versions
docker version --format '{{.Server.Version}}'  # Server version only
docker version --format json                   # JSON output
```

### docker context

```bash
docker context ls                                                    # List all contexts
docker context create remote --docker "host=ssh://user@remote-host"  # Create SSH context
docker context use remote                                            # Switch to context
docker context use default                                           # Switch back
docker context inspect remote                                        # Show details
docker context rm remote                                             # Remove context
```

---

## Reference Links

- [references/commands.md](references/commands.md) -- Complete image and system command reference with all flags
- [references/examples.md](references/examples.md) -- Image management workflows and cleanup scripts
- [references/anti-patterns.md](references/anti-patterns.md) -- Common image management mistakes and how to avoid them

### Official Sources

- https://docs.docker.com/reference/cli/docker/image/
- https://docs.docker.com/reference/cli/docker/buildx/build/
- https://docs.docker.com/reference/cli/docker/image/ls/
- https://docs.docker.com/reference/cli/docker/system/
- https://docs.docker.com/reference/cli/docker/system/prune/
- https://docs.docker.com/reference/cli/docker/system/df/

## 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](https://github.com/Impertio-Studio)
- **Source:** [Impertio-Studio/Docker-Claude-Skill-Package](https://github.com/Impertio-Studio/Docker-Claude-Skill-Package)
- **License:** MIT

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

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-impertio-studio-docker-claude-skill-package-docker-syntax-cli-images
- Seller: https://agentstack.voostack.com/s/impertio-studio
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.