Rene Nochebuena
e978d60851
Introduces code.nochebuena.dev/einherjar/spa-server — a container-first HTTP
server for single-page applications and progressive web apps. Produces a Docker
base image; downstream SPA Dockerfiles require only a single COPY instruction.
Interfaces and types (CT-6: one TypeSpec per file):
- Config — Port (EINHERJAR_SPA_PORT, default 8080) and StaticDir
(EINHERJAR_SPA_STATIC_DIR, default /srv/www); parsed via os.Getenv
- Server — implements lifecycle.Component; registered with launcher.New
Implementation:
- NewServer(logger, cfg) *Server — returns a lifecycle-managed HTTP server
- OnInit: builds http.NewServeMux with GET /health and /* routes
- OnStart: binds TCP listener synchronously via net.Listen (port conflicts
surface immediately), then serves in a background goroutine
- OnStop: graceful shutdown via http.Server.Shutdown with 10s timeout
spa.NewHandler(logger, staticDir) http.Handler:
- Uses http.Dir.Open for path sanitisation (prevents directory traversal)
- File exists and is not a directory → served by http.FileServer
- File missing or is a directory → serves index.html (SPA router owns all routes)
- Directory listing is disabled
health.NewHandler(logger) http.Handler:
- Always responds 200 {"status":"UP","components":{}}
- Wire format matches web/health.Response without importing the web module
- No external checks — process reachability is the only meaningful health signal
Config (EINHERJAR_SPA_* env vars):
Port(8080), StaticDir(/srv/www)
Docker:
- Multi-stage: golang:1.26-alpine builder → alpine:3.21 runtime
- Image published as:
code.nochebuena.dev/einherjar/spa-server:v1.0.0
code.nochebuena.dev/einherjar/spa-server:latest
- VOLUME ["/srv/www"] declared; consumer overrides via COPY or volume mount
No external dependencies beyond contracts, core, and the Go standard library.
47 lines
1.2 KiB
Go
47 lines
1.2 KiB
Go
// Package spa provides the HTTP handler that serves a single-page application.
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package spa
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import (
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"net/http"
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"path/filepath"
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"code.nochebuena.dev/einherjar/contracts/logging"
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)
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type handler struct {
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logger logging.Logger
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staticDir string
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fs http.Handler
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}
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// NewHandler returns an http.Handler that serves static files from staticDir.
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// Requests for paths that exist on disk are served directly.
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// Any other path receives index.html, delegating routing to the SPA.
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func NewHandler(logger logging.Logger, staticDir string) http.Handler {
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return &handler{
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logger: logger,
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staticDir: staticDir,
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fs: http.FileServer(http.Dir(staticDir)),
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}
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}
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func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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// http.Dir.Open sanitises the path, preventing directory traversal.
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f, err := http.Dir(h.staticDir).Open(r.URL.Path)
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if err != nil {
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// Path does not exist — hand off to the SPA router.
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http.ServeFile(w, r, filepath.Join(h.staticDir, "index.html"))
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return
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}
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defer f.Close()
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stat, err := f.Stat()
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if err != nil || stat.IsDir() {
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// Directory listing is disabled; treat directories as SPA routes.
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http.ServeFile(w, r, filepath.Join(h.staticDir, "index.html"))
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return
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}
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h.fs.ServeHTTP(w, r)
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}
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