spa-to-http

Lightweight zero-configuration SPA HTTP server. Serves SPA bundle on HTTP port which makes it play well with traefik

Benefits

Zero-configuration in Docker without managing additional configs
10x times smaller then Nginx, faster startup time, a bit better or same performance
Plays well with all popular SPA frameworks and libraries: Vue, React, Angular, Svelte and bundlers: Webpack/Vite
Supports Brotly compression on original files, you don't need to archivate files by yourself, it does it for you
Written in Go, which makes it fast (no overhead on runtime) and tiny (small binary size)
Open-Source commercial friendly MIT license
Optimal statics caching out of the box: no-cache on index.html file to auto-update caches and infinite max-age for all other resources which have hash-URLs in most default SPA bundlers.
Plays well with CDNs caching (e.g. Clouflare), support for ignoring cache of fixed URLs like service worker
Created and maintained by Devforth 💪🏼

Spa-to-http vs Nginx

	Spa-to-http	Nginx
Zero-configuration	✅No config files, SPA serving works out of the box with most optimal settings	❌Need to create a dedicated config file
Ability to config settings like host, port, compression using Environment variables or CLI	✅Yes	❌No, only text config file
Docker image size	✅13.2 MiB (v1.0.3)	❌142 MiB (v1.23.1)
Brotli compression out-of-the-box	✅Yes, just set env BROTLI=true	❌You need a dedicated module like ngx_brotli

Performence accroding to Spa-to-http vs Nginx benchmark (End of the post)

	Spa-to-http	Nginx
Average time from container start to HTTP port availability (100 startups)	✅1.358 s (11.5% faster)	❌1.514s
Requests-per-second on 0.5 KiB HTML file at localhost *	✅80497 (1.6% faster)	❌79214
Transfer speed on 0.5 KiB HTML file *	❌74.16 MiB/sec	✅75.09 MiB/sec (1.3% faster)
Requests-per-second on 5 KiB JS file at localhost *	✅66126 (5.2% faster)	❌62831
Transfer speed on 5 KiB HTML file *	✅301.32 MiB/sec (4.5% faster)	❌288.4

Hello world & ussage

Create Dockerfile in yoru SPA directory (near package.json):

FROM node:16-alpine as builder
WORKDIR /code/
ADD package-lock.json .
ADD package.json .
RUN npm ci
ADD . .
RUN npm run build

FROM devforth/spa-to-http:latest
COPY --from=builder /code/dist/ .

So we built our frontend and included it into container based on Spa-to-http. This way gives us great benefits:

We build frontend in docker build time and improve build time for most changes (npm ci is not getting rebuild if there is no new packages)
Bundle has only small resulting dist folder, there is no source code and node_modules so countainer is small
When you start this container it serves SPA on HTTP port automatically with best settings. Spa-to-http already has right CMD inside which runs SPA-to-HTTP webserver with right caching

Example serving SPA with Traefik and Docker-Compose

version: "3.3"

services:

  traefik:
    image: "traefik:v2.7"
    command:
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
      - "--entrypoints.web.address=:80"
    ports:
      - "80:80"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"

  trfk-vue:
    build: "spa" # name of the folder where Dockerfile is located
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.trfk-vue.rule=Host(`trfk-vue.localhost`)"
      - "traefik.http.services.trfk-vue.loadbalancer.server.port=8080" # port inside of trfk-vue which should be used

How to enable Brotli compression:

 trfk-vue:
    build: "spa"
++  command: --brotli
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.trfk-vue.rule=Host(`trfk-vue.localhost`)"
      - "traefik.http.services.trfk-vue.loadbalancer.server.port=8080"

How to change thresshold of small files which should not be compressed:

 trfk-vue:
    build: "spa"
--  command: --brotli
++  command: --brotli --threshold 500
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.trfk-vue.rule=Host(`trfk-vue.localhost`)"
      - "traefik.http.services.trfk-vue.loadbalancer.server.port=8080"

How to run container on a custom port:

 trfk-vue:
    build: "spa"
++  command: --brotli --port 8082
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.trfk-vue.rule=Host(`trfk-vue.localhost`)"
--    - "traefik.http.services.trfk-vue.loadbalancer.server.port=8080"
++    - "traefik.http.services.trfk-vue.loadbalancer.server.port=8082"

Ignore caching for some specific resources, e.g. prevent Service Worker caching on CDNs like Cloudflare:

 trfk-vue:
    build: "spa"
++  command: --ignore-cache-control-paths "/sw.js"
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.trfk-vue.rule=Host(`trfk-vue.localhost`)"
      - "traefik.http.services.trfk-vue.loadbalancer.server.port=8080"

This is not needed for most of your assets because their filenames should contain file hash (added by default by modern bundlers). So cache naturally invalidated by referencing hashed assets from uncachable html. However some special resources like service worker must be served on fixed URL without file hash in filename

Available Options:

Environment Variable	Command	Description	Defaults
ADDRESS	`-a` or `--address`	Address to use	0.0.0.0
PORT	`-p` or `--port`	Port to listen on	8080
GZIP	`--gzip`	When enabled it will create .gz files using gzip compression for files which size exceedes threshold and serve it instead of original one if client accepts gzip encoding. If brotli also enabled it will try to serve brotli first	`false`
BROTLI	`--brotli`	When enabled it will create .br files using brotli compression for files which size exceedes threshold and serve it instead of original one if client accepts brotli encoding. If gzip also enabled it will try to serve brotli first	`false`
THRESHOLD	`--threshold <number>`	Threshold in bytes for gzip and brotli compressions	1024
DIRECTORY	`-d <string>` or `--directory <string>`	Directory to serve	`.`
CACHE_CONTROL_MAX_AGE	`--cache-control-max-age <number>`	Set cache time (in seconds) for cache-control max-age header To disable cache set to -1. `.html` files are not being cached	604800
IGNORE_CACHE_CONTROL_PATHS	`--ignore-cache-control-paths <string>`	Additional paths to set "Cache-control: no-store" via comma, example "/file1.js,/file2.js"
SPA_MODE	`--spa` or `--spa <bool>`	When SPA mode if file for requested path does not exists server returns index.html from root of serving directory. SPA mode and directory listing cannot be enabled at the same time	`true`
CACHE	`--cache`	When enabled f.Open reads are being cached using Two Queue LRU Cache in bits	`true`
CACHE_BUFFER	`--cache-buffer <number>`	Specifies the maximum size of LRU cache in bytes	`51200`
LOGGER	`--logger`	Enable requests logger	`false`
LOG_PRETTY	`--log-pretty`	Print log messages in a pretty format instead of default JSON format	`false`