Go's MIME table has no .webmanifest entry, so http.FileServer sniffed the PWA web
app manifest as text/plain. mime.AddExtensionType at package load makes TypeByExtension
authoritative. A correctness nit (the manifest spec parses by content and nosniff does
not reject manifests), but a PWA server should label its manifest correctly.
- Cache-Control per file: no-cache for index.html + service workers, immutable 1y for
content-hashed assets, 1h for the rest (Vite/CRA/Angular). Closes the stale-release
trap at the HTTP layer that the v1.6.0 image fix closed at the container layer.
- SPA fallback scoped to navigation: a missing asset (path w/ extension) or a non-HTML
Accept now returns 404 instead of index.html (no more HTML-as-JS 'Unexpected token <').
- X-Content-Type-Options: nosniff on every response.
- Image runs as a non-root 'spa' user.
- README: caching table, fallback contract, and the Angular dist/<project>/browser/ note.
VOLUME ["/srv/www"] created an anonymous volume that docker compose reuses across
container recreation, shadowing a freshly COPY'd SPA bundle with the previous build
— up -d --build exited 0 while serving the old bundle (and poisoned the PWA service
worker's ngsw.json). A child image cannot un-declare an inherited VOLUME, so it must
not be declared: removing it makes the COPY case deterministic and leaves the runtime
bind-mount case unaffected. Also refreshed the README FROM tag v1.0.0 -> v1.6.0.
Patch of the coordinated framework release: einherjar modules move to v1.1.0
in lockstep, so spa-server is bumped alongside the rest.
- go.mod: contracts, core -> v1.1.0 (via go get + go mod tidy)
No code or API changes. ModuleVersion() reports v1.1.0 automatically from
build info once tagged. Badge bumped to v1.1.0.
Reviewed-on: #1
Co-authored-by: Rene Nochebuena Guerrero <rene@nochebuena.dev>
Co-committed-by: Rene Nochebuena Guerrero <rene@nochebuena.dev>
Makefile:
- dry-run target (default) shows registry, branch, SHA, version, all computed
image tags, and build args — no side effects
- build/push/release targets wire docker build and docker push
- Branch-aware tag strategy:
main → <version> + latest
develop → <version>-dev-<short-sha>
release/* → <version>-qa-<short-sha>
- Version resolved from the highest semver tag at HEAD; falls back to the most
recent reachable tag via git describe
- BASE_DIGEST resolved at build time from the local Docker daemon; dry-run
prints a hint when the base image is not yet pulled
- Note: case/esac cannot be used inside $(shell) — Make's parser matches the
pattern ")" as the function's closing paren before the shell sees it;
if/elif/else/fi used instead
Dockerfile:
- OCI standard labels added to the final stage via build args (VERSION, GIT_SHA,
BASE_DIGEST):
org.opencontainers.image.source — repo URL
org.opencontainers.image.version — semver tag
org.opencontainers.image.revision — git commit SHA
org.opencontainers.image.base.name — alpine:3.21
org.opencontainers.image.base.digest — digest of base image at build time
- Custom label:
dev.nochebuena.healthz — /health
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.
Rene Nochebuena
