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.

Evaluating another agent? The competitive landscape compares the current Portainer, Komodo, Arcane, and Hawser agent models, records primary sources, and separates Portwing responsibilities from Drydock and Sockguard features.

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.