viws

viws

A superlight HTTP fileserver with customizable behavior.

Installation

go install github.com/ViBiOh/viws/cmd/viws@latest

Light version

Light version (without GZIP and Prometheus) is also available, for a smaller binary.

go install github.com/ViBiOh/viws/cmd/viws-light@latest

Features

• Full TLS support
• GZIP Compression
• Prometheus monitoring on dedicated port
• Read-only container
• Serve static content, with Single Page App handling
• Serve environment variables for easier-config
• Configurable logger with JSON support

Single Page Application

This mode is useful when you have a router in your javascript framework (e.g. Angular/React/Vue). When a request target a not found file, it returns the index instead of 404. This option also deactivates cache for the index in order to make work the cache-buster for javascript/style files.

curl myWebsite.com/users/vibioh/
=> /index.html

Endpoints

• GET /health: healthcheck of server, always respond okStatus (default 204)
• GET /ready: checks external dependencies availability and then respond okStatus (default 204) or 503 during graceDuration when SIGTERM is received
• GET /version: value of VERSION environment variable
• GET /metrics: Prometheus metrics, on a dedicated port prometheusPort (default 9090)
• GET /env: values of specified environments variables

Environment variables

Environment variables are exposed as JSON from a single and easy to remember endpoint: /env. You have full control of exposed variables by declaring them on the CLI.

This feature is useful for Single Page Application, you first request /env in order to know the API_URL or CONFIGURATION_TOKEN and then proceed. You reuse the same artifact between pre-production and production, only variables change, in respect of 12factor app

Configuration example

API_URL=https://api.vibioh.fr vibioh/viws --env API_URL

> curl http://localhost:1080/env
{"API_URL":"https://api.vibioh.fr"}

Usage in SPA

// index.js

const response = await fetch("/env");
const config = await response.json();
ReactDOM.render(<App config={config} />, document.getElementById("root"));

Usage

By default, server is listening on the 1080 port and serve content for GET requests from the /www/ directory. It assumes that HTTPS is done, somewhere between browser and server (e.g. CloudFlare, ReverseProxy, Traefik, ...) so it sets HSTS flag by default.

The application can be configured by passing CLI args described below or their equivalent as environment variable. CLI values take precedence over environments variables.

Be careful when using the CLI values, if someone list the processes on the system, they will appear in plain-text. Pass secrets by environment variables: it's less easily visible.

Usage of viws:
  -address string
        [server] Listen address {VIWS_ADDRESS}
  -cert string
        [server] Certificate file {VIWS_CERT}
  -corsCredentials
        [cors] Access-Control-Allow-Credentials {VIWS_CORS_CREDENTIALS}
  -corsExpose string
        [cors] Access-Control-Expose-Headers {VIWS_CORS_EXPOSE}
  -corsHeaders string
        [cors] Access-Control-Allow-Headers {VIWS_CORS_HEADERS} (default "Content-Type")
  -corsMethods string
        [cors] Access-Control-Allow-Methods {VIWS_CORS_METHODS} (default "GET")
  -corsOrigin string
        [cors] Access-Control-Allow-Origin {VIWS_CORS_ORIGIN} (default "*")
  -csp string
        [owasp] Content-Security-Policy {VIWS_CSP} (default "default-src 'self'; base-uri 'self'")
  -directory string
        [viws] Directory to serve {VIWS_DIRECTORY} (default "/www/")
  -env value
        [env] Environments key variable to expose {VIWS_ENV}
  -frameOptions string
        [owasp] X-Frame-Options {VIWS_FRAME_OPTIONS} (default "deny")
  -graceDuration duration
        [http] Grace duration when SIGTERM received {VIWS_GRACE_DURATION} (default 30s)
  -gzip
        [gzip] Enable gzip compression {VIWS_GZIP} (default true)
  -header value
        [viws] Custom header e.g. content-language:fr {VIWS_HEADER}
  -hsts
        [owasp] Indicate Strict Transport Security {VIWS_HSTS} (default true)
  -idleTimeout duration
        [server] Idle Timeout {VIWS_IDLE_TIMEOUT} (default 2m0s)
  -key string
        [server] Key file {VIWS_KEY}
  -loggerJson
        [logger] Log format as JSON {VIWS_LOGGER_JSON}
  -loggerLevel string
        [logger] Logger level {VIWS_LOGGER_LEVEL} (default "INFO")
  -loggerLevelKey string
        [logger] Key for level in JSON {VIWS_LOGGER_LEVEL_KEY} (default "level")
  -loggerMessageKey string
        [logger] Key for message in JSON {VIWS_LOGGER_MESSAGE_KEY} (default "message")
  -loggerTimeKey string
        [logger] Key for timestamp in JSON {VIWS_LOGGER_TIME_KEY} (default "time")
  -okStatus int
        [http] Healthy HTTP Status code {VIWS_OK_STATUS} (default 204)
  -port uint
        [server] Listen port (0 to disable) {VIWS_PORT} (default 1080)
  -prometheusAddress string
        [prometheus] Listen address {VIWS_PROMETHEUS_ADDRESS}
  -prometheusCert string
        [prometheus] Certificate file {VIWS_PROMETHEUS_CERT}
  -prometheusGzip
        [prometheus] Enable gzip compression of metrics output {VIWS_PROMETHEUS_GZIP} (default true)
  -prometheusIdleTimeout duration
        [prometheus] Idle Timeout {VIWS_PROMETHEUS_IDLE_TIMEOUT} (default 10s)
  -prometheusIgnore string
        [prometheus] Ignored path prefixes for metrics, comma separated {VIWS_PROMETHEUS_IGNORE}
  -prometheusKey string
        [prometheus] Key file {VIWS_PROMETHEUS_KEY}
  -prometheusPort uint
        [prometheus] Listen port (0 to disable) {VIWS_PROMETHEUS_PORT} (default 9090)
  -prometheusReadTimeout duration
        [prometheus] Read Timeout {VIWS_PROMETHEUS_READ_TIMEOUT} (default 5s)
  -prometheusShutdownTimeout duration
        [prometheus] Shutdown Timeout {VIWS_PROMETHEUS_SHUTDOWN_TIMEOUT} (default 5s)
  -prometheusWriteTimeout duration
        [prometheus] Write Timeout {VIWS_PROMETHEUS_WRITE_TIMEOUT} (default 10s)
  -readTimeout duration
        [server] Read Timeout {VIWS_READ_TIMEOUT} (default 5s)
  -shutdownTimeout duration
        [server] Shutdown Timeout {VIWS_SHUTDOWN_TIMEOUT} (default 10s)
  -spa
        [viws] Indicate Single Page Application mode {VIWS_SPA}
  -tracerRate string
        [tracer] OpenTracing sample rate, 'always', 'never' or a float value {VIWS_TRACER_RATE} (default "always")
  -tracerURL string
        [tracer] OpenTracing gRPC endpoint (e.g. otel-exporter:4317) {VIWS_TRACER_URL}
  -url string
        [alcotest] URL to check {VIWS_URL}
  -userAgent string
        [alcotest] User-Agent for check {VIWS_USER_AGENT} (default "Alcotest")
  -writeTimeout duration
        [server] Write Timeout {VIWS_WRITE_TIMEOUT} (default 10s)

Docker

docker run -d --name website \
  -p 1080:1080/tcp \
  -v "$(pwd):/www/:ro" \
  vibioh/viws

We recommend using a Dockerfile to ship your files inside it.

e.g.

FROM vibioh/viws

ENV VERSION 1.2.3-1234abcd
COPY dist/ /www/

Light image

Image with tag :light is also available.

e.g.

FROM vibioh/viws:light

ENV VERSION 1.0.0-1234abcd
COPY dist/ /www/

Compilation

You need Go 1.12+ with go modules enabled in order to compile the project.

make go

License