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.
37 lines
911 B
Go
37 lines
911 B
Go
package spaserver
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import (
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"os"
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"strconv"
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)
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// Config holds the server configuration.
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// All fields are populated from environment variables by [DefaultConfig].
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type Config struct {
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// Port is the TCP port the server listens on.
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Port int `env:"EINHERJAR_SPA_PORT" envDefault:"8080"`
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// StaticDir is the filesystem path that contains index.html and all assets.
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StaticDir string `env:"EINHERJAR_SPA_STATIC_DIR" envDefault:"/srv/www"`
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}
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// DefaultConfig returns a Config populated from environment variables,
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// falling back to safe defaults when variables are unset.
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func DefaultConfig() Config {
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port := 8080
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if v := os.Getenv("EINHERJAR_SPA_PORT"); v != "" {
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if p, err := strconv.Atoi(v); err == nil && p > 0 {
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port = p
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}
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}
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staticDir := "/srv/www"
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if v := os.Getenv("EINHERJAR_SPA_STATIC_DIR"); v != "" {
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staticDir = v
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}
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return Config{
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Port: port,
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StaticDir: staticDir,
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}
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}
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