molecule-core/platform/internal/middleware/securityheaders.go
Hongming Wang b8cb14f46e feat(tenant): combined platform + canvas Docker image with reverse proxy
Single-container tenant architecture: Go platform (:8080) + Canvas
Node.js (:3000) in one Fly machine, with Go's NoRoute handler reverse-
proxying non-API routes to the canvas. Browser only talks to :8080.

Changes:

platform/Dockerfile.tenant — multi-stage build (Go + Node + runtime).
  Bakes workspace-configs-templates/ + org-templates/ into the image.
  Build context: repo root.

platform/entrypoint-tenant.sh — starts both processes, kills both if
  either exits. Fly health check on :8080 covers the Go binary; canvas
  health is implicit (proxy returns 502 if canvas is down).

platform/internal/router/canvas_proxy.go — httputil.ReverseProxy that
  forwards unmatched routes to CANVAS_PROXY_URL (http://localhost:3000).
  Activated by NoRoute when CANVAS_PROXY_URL env is set.

platform/internal/router/router.go — wire NoRoute → canvasProxy when
  CANVAS_PROXY_URL is present; no-op otherwise (local dev unchanged).

platform/internal/middleware/securityheaders.go — relaxed CSP to allow
  Next.js inline scripts/styles/eval + WebSocket + data: URIs. The
  strict `default-src 'self'` was blocking all canvas rendering.

canvas/src/lib/api.ts — changed `||` to `??` for NEXT_PUBLIC_PLATFORM_URL
  so empty string means "same-origin" (combined image) instead of falling
  back to localhost:8080.

canvas/src/components/tabs/TerminalTab.tsx — same `??` fix for WS URL.

Verified: tenant machine boots, canvas renders, 8 runtime templates +
4 org templates visible, API routes work through the same port.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-16 02:46:47 -07:00

54 lines
2.7 KiB
Go

package middleware
import "github.com/gin-gonic/gin"
// SecurityHeaders returns a Gin middleware that sets standard HTTP security
// headers on every response to mitigate common web-application attacks:
//
// - X-Content-Type-Options: nosniff — prevents MIME-type sniffing
// - X-Frame-Options: DENY — blocks iframe embedding (clickjacking)
// - Content-Security-Policy: default-src 'self' — restricts resource loading to same origin
// - Strict-Transport-Security: max-age=31536000; includeSubDomains — enforces HTTPS for 1 year
// - Referrer-Policy: strict-origin-when-cross-origin — avoids leaking full paths/queries in Referer
// - Permissions-Policy: camera=(), microphone=(), geolocation=() — denies sensor access for embedded content
func SecurityHeaders() gin.HandlerFunc {
return func(c *gin.Context) {
c.Header("X-Content-Type-Options", "nosniff")
c.Header("X-Frame-Options", "DENY")
c.Header("Strict-Transport-Security", "max-age=31536000; includeSubDomains")
// #282: these two were documented in CLAUDE.md but missing from
// the middleware. Referrer-Policy prevents browsers from leaking
// the full Referer URL to cross-origin resources (which can
// expose internal paths/queries). Permissions-Policy denies
// sensor access by default — especially relevant because the
// canvas embeds iframes for Langfuse traces.
c.Header("Referrer-Policy", "strict-origin-when-cross-origin")
c.Header("Permissions-Policy", "camera=(), microphone=(), geolocation=()")
// CSP: only apply to API responses. Canvas-proxied routes
// (NoRoute → reverse-proxy to Next.js) serve HTML with inline
// scripts + styles that `default-src 'self'` blocks. Next.js
// sets its own CSP via <meta> tags. The Go middleware should
// not override it for proxied HTML responses.
//
// Detection: API routes are registered explicitly in the router;
// canvas-proxied routes hit NoRoute. We can't detect NoRoute
// before c.Next() fires, so instead we check the response
// Content-Type after Next() — but that's too late for headers.
//
// Simpler: apply a permissive CSP that allows Next.js to work.
// 'unsafe-inline' + 'unsafe-eval' are needed for Next.js dev
// hydration; in production Next.js uses nonces but we don't
// propagate them through the proxy. This is acceptable because
// the canvas is our own code, not user-generated content.
c.Header("Content-Security-Policy",
"default-src 'self'; "+
"script-src 'self' 'unsafe-inline' 'unsafe-eval'; "+
"style-src 'self' 'unsafe-inline'; "+
"img-src 'self' data: blob:; "+
"connect-src 'self' ws: wss:; "+
"font-src 'self' data:")
c.Next()
}
}