Introduction

A security-first remote Docker agent. Control your containers from anywhere, safely.

Why Portwing?

The Docker socket (/var/run/docker.sock) is effectively root on your host. Most remote-management agents mount it straight in and hope nothing goes wrong — a compromised agent, a leaked token, or a single missing check is enough to own the box. Portwing is built the other way around: deny by default, prove every action, and never touch the raw socket if you can avoid it.

Portwing is the remote agent for Drydock — one controller managing containers across every one of your hosts — and it runs happily standalone too.

• Default-deny socket — bundle the sibling project Sockguard and Portwing talks to a filtered unix socket instead of the raw daemon. Even a fully compromised agent is constrained to an explicit Docker API allowlist.
• Ed25519 per-client auth — signed requests with replay protection and no shared secrets on the wire. Prefer a token? Store only its Argon2id hash.
• Signed & verifiable — every release ships cosign signatures, per-archive SBOMs, an image SBOM attestation, and SLSA provenance. Verify the image before you trust it.
• Hardened runtime — ships to run read_only, cap_drop: ALL, and no-new-privileges, with tokens delivered as mounted secrets.
• Structured audit log — every action recorded as JSON; auth and key-enrollment events are first-class. Export to immutable storage for tamper evidence.
• Zero-dependency metrics — a cAdvisor-compatible /metrics endpoint drops into the dashboards you already run.
• AI-native — a read-only Model Context Protocol server exposes host and container state to MCP-aware agents.
• Tiny & multi-arch — a single static Go binary, ~10 MB, for amd64 · arm64 · arm/v7.

Architecture

One Drydock controller connects inbound to a Portwing agent on each host. Each agent reaches the Docker Engine only through a Sockguard socket filter:

                         ┌──────────── Remote host A ───────────┐
                         │  Portwing → sockguard → Docker Engine  │
   Drydock ──HTTPS+SSE──▶│                                       │
  (controller)           └───────────────────────────────────────┘
        │                ┌──────────── Remote host B ───────────┐
        └─────HTTPS+SSE─▶│  Portwing → sockguard → Docker Engine  │
                         └───────────────────────────────────────┘

Quick Start

The strongest posture runs Portwing and Sockguard as two hardened containers sharing a filtered socket — neither mounts the raw Docker socket directly:

openssl rand -hex 32 > portwing_token.txt
curl -fsSLO https://raw.githubusercontent.com/CodesWhat/portwing/main/examples/docker-compose.with-sockguard.yml
curl -fsSLO https://raw.githubusercontent.com/CodesWhat/portwing/main/examples/sockguard.yaml
docker compose -f docker-compose.with-sockguard.yml up -d

See Getting Started for the full compose file, the edge-mode variant, and the upgrade to Ed25519 key authentication.