garcon

package module
v0.35.2 Latest Latest
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 Go to latest Published: Jul 15, 2024 License: MIT Imports: 37 Imported by: 7

README

Teal.Finance/Garcon

logo Garcon works with all HTTP routers ans middleware respecting the Go HTTP standards. Garcon provides the batteries: static website server, contact-form backend, API helpers, debugging helpers (PProf), Git version, exporter server (Prometheus), health endpoints (Kubernetes), URI sanitization and middleware: rate-limiter, JWT cookies, CORS, traffic logs, OPA…
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Motivation

Many projects often start with one of the many nice HTTP routers and middleware already available and develop their own middleware, debugging server, API helpers... At Teal.Finance, we decided to share in one place (here) all our stuff in the idea to let other projects go faster.

Middleware

Our Middleware are very easy to setup. They respect the Go standards. Thus you can easily use them with the HTTP router of your choice and chained them with other middleware:

  • MiddlewareLogRequest Log incoming requests (with or without browser fingerprint)
  • MiddlewareLogDuration Log processing time
  • MiddlewareExportTrafficMetrics Export web traffic metrics
  • MiddlewareRejectUnprintableURI Reject request with unwanted characters
  • MiddlewareRateLimiter Limit incoming request to prevent flooding
  • MiddlewareServerHeader Add the "Server" HTTP header in the response
  • JWTChecker JWT management using HttpOnly cookie or Authorization header
  • IncorruptibleChecker Session cookie with Incorruptible token
  • MiddlewareCORS Cross-Origin Resource Sharing (CORS)
  • MiddlewareOPA Authenticate from Datalog/Rego files using Open Policy Agent
  • MiddlewareSecureHTTPHeader Set some HTTP header to increase the web security
g := garcon.New()
middleware = garcon.NewChain(
    g.MiddlewareRejectUnprintableURI(),
    g.MiddlewareLogRequest(),
    g.MiddlewareRateLimiter())
router  := ... you choose
handler := middleware.Then(router)
server  := http.Server{Addr: ":8080", Handler: handler}
server.ListenAndServe()

Other features

  • Static web files server supporting Brotli and AVIF
  • Metrics server exporting data to Prometheus (or other compatible monitoring tool)
  • Health status server for Kubernetes liveness and readiness probes
  • PProf server for debugging purpose
  • Serialize JSON responses, including the error messages
  • Chained middleware (fork of justinas/alice)
  • Chained round trip handlers
  • Retrieve Git version, branch and commit from build flags and Go module information

Basic example

g := garcon.New()

// chain some middleware
middleware = garcon.NewChain(
    g.MiddlewareRejectUnprintableURI(),
    g.MiddlewareLogRequests(),
    g.MiddlewareRateLimiter())

// use the HTTP router library of your choice, here we use Chi 
router := chi.NewRouter()

// static website, automatically sends the Brotli-compressed file if present and supported by the browser
ws := g.NewStaticWebServer("/var/www")
router.Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))
router.Get("/favicon.ico", ws.ServeFile("favicon.ico", "image/x-icon"))
router.Get("/js/*", ws.ServeDir("text/javascript; charset=utf-8"))
router.Get("/css/*", ws.ServeDir("text/css; charset=utf-8"))
router.Get("/images/*", ws.ServeImages()) // automatically sends AVIF if present and supported by the browser

// receive contact-forms on your chat channel on the fly
cf := g.NewContactForm("/")
router.Post("/", cf.Notify("https://mattermost.com/hooks/qite178czotd5"))

// Git version and last commit date (HTML or JSON depending on the "Accept" header)
router.Get("/version", garcon.ServeVersion())

// return a JSON message
router.Get("/reserved", g.Writer.NotImplemented)
router.NotFound(g.Writer.InvalidPath)

handler := middleware.Then(router)
server := http.Server{Addr: ":8080", Handler: handler}
server.ListenAndServe()

Incorruptible middleware

Garcon uses the Incorruptible package to create/verify session cookie.

package main

import "github.com/teal-finance/garcon"

func main() {
    g, _ := garcon.New(
        garcon.WithURLs("https://my-company.com"),
        garcon.WithDev())

    aes128Key = "00112233445566778899aabbccddeeff"
    maxAge := 3600
    setIP := true
    ck := g.IncorruptibleChecker(aes128Key, maxAge, setIP)

    router := chi.NewRouter()

    // website with static files directory
    ws := g.NewStaticWebServer("/var/www")

    // ck.Set => set the cookie when visiting /
    router.With(ck.Set).Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))

    // ck.Chk => reject request with invalid JWT cookie
    router.With(ck.Chk).Get("/js/*", ws.ServeDir("text/javascript; charset=utf-8"))
    router.With(ck.Chk).Get("/assets/*", ws.ServeAssets())

    // ck.Vet => accepts valid JWT in either the cookie or the Authorization header
    router.With(ck.Vet).Post("/api/items", myFunctionHandler)

    server := http.Server{Addr: ":8080", Handler: router}
    server.ListenAndServe()
}

JWT middleware

The JWT and Incorruptible checkers share a common interface, TokenChecker, providing the same middleware: Set(), Chk() and Vet().

package main

import "github.com/teal-finance/garcon"

func main() {
    g, _ := garcon.New(
        garcon.WithURLs("https://my-company.com"),
        garcon.WithDev())

    hmacSHA256Key := "9d2e0a02121179a3c3de1b035ae1355b1548781c8ce8538a1dc0853a12dfb13d"
    ck := g.JWTChecker(hmacSHA256Key, "FreePlan", 10, "PremiumPlan", 100)

    router := chi.NewRouter()

    // website with static files directory
    ws := g.NewStaticWebServer("/var/www")

    // ck.Set => set the cookie when visiting /
    router.With(ck.Set).Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))

    // ck.Chk => reject request with invalid JWT cookie
    router.With(ck.Chk).Get("/js/*", ws.ServeDir("text/javascript; charset=utf-8"))
    router.With(ck.Chk).Get("/assets/*", ws.ServeAssets())

    // ck.Vet => accepts valid JWT in either the cookie or the Authorization header
    router.With(ck.Vet).Post("/api/items", myFunctionHandler)

    server := http.Server{Addr: ":8080", Handler: router}
    server.ListenAndServe()
}

Who use Garcon

In production, this library is used by Rainbow, Quid and other internal projects at Teal.Finance.

Please propose a Pull Request to add here your project that also uses Garcon.

See a complete real example in the repo github.com/teal-finance/rainbow.

CPU profiling

Moreover, Garcon simplifies investigation on CPU and memory consumption issues thanks to https://github.com/pkg/profile.

In your code, add defer garcon.ProbeCPU.Stop() that will write the cpu.pprof file.

import "github.com/teal-finance/garcon"

func myFunctionConsumingLotsOfCPU() {
    defer garcon.ProbeCPU.Stop()

    // ... lots of sub-functions
}

Run pprof and browse your cpu.pprof file:

go run github.com/google/pprof@latest -http=: cpu.pprof

Complete example

See the complete example enabling almost of the Garcon features. Below is a simplified extract:

package main

import "github.com/teal-finance/garcon"

func main() {
    defer garcon.ProbeCPU().Stop() // collects the CPU-profile and writes it in the file "cpu.pprof"

    garcon.LogVersion()     // log the Git version
    garcon.SetVersionFlag() // the -version flag prints the Git version
    jwt := flag.Bool("jwt", false, "Use JWT in lieu of the Incorruptible token")
    flag.Parse()

    g := garcon.New(
        garcon.WithURLs("https://my-company.co"),
        garcon.WithDocURL("/doc"),
        garcon.WithPProf(8093))

    ic := g.IncorruptibleChecker(aes128Key, 60, true)
    jc := g.JWTChecker(hmacSHA256Key, "FreePlan", 10, "PremiumPlan", 100)

    middleware, connState := g.StartExporter(9093)
    middleware = middleware.Append(
        g.MiddlewareRejectUnprintableURI(),
        g.MiddlewareLogRequests("fingerprint"),
        g.MiddlewareRateLimiter(10, 30),
        g.MiddlewareServerHeader("MyApp"),
        g.MiddlewareCORS(),
        g.MiddlewareOPA("auth.rego"),
        g.MiddlewareLogDuration(true()))

    router := chi.NewRouter()

    // website with static files directory
    ws := g.NewStaticWebServer("/var/www")
    router.With(ic.Set).With(jc.Set).Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))
    router.With(ic.Chk).Get("/assets/*", ws.ServeAssets())

    // Contact-form
    cf := g.NewContactForm("/")
    router.Post("/", cf.Notify("https://mattermost.com/hooks/qite178czotd5"))

    // API
    router.With(jc.Vet).Post("/api/items", myFunctionHandler)

    handler := middleware.Then(router)
    server := garcon.Server(handler, 8080, connState)
    garcon.ListenAndServe(&server)
}
1. Run the complete example
cd garcon
go run -race ./examples/complete

garcon ℹ️  Probing CPU. To visualize the profile: pprof -http=: cpu.pprof
2022/09/14 18:43:05 profile: cpu profiling enabled, cpu.pprof
garcon 🎬  Version: devel
garcon ℹ️  Enable PProf endpoints: http://localhost:8093/debug/pprof
incorr 🔒  DevMode accepts missing/invalid token from http://localhost:8080/myapp
incorr 🔒  cookie myapp Domain=localhost Path=/myapp Max-Age=60 Secure=false SameSite=3 HttpOnly=true Value=0 bytes
garcon ℹ️  Prometheus export http://localhost:9093 namespace=myapp
garcon 🔒  CORS Allow origin prefixes: [http://localhost:8080 http://localhost: http://192.168.1.]
garcon 🔒  CORS Methods: [GET POST DELETE]
garcon 🔒  CORS Headers: [Origin Content-Type Authorization]
garcon 🔒  CORS Credentials=true MaxAge=86400
incorr 🔒  Middleware Incorruptible.Set cookie "myapp" MaxAge=60 setIP=true
incorr 🔒  Middleware Incorruptible.Set cookie "myapp" MaxAge=60 setIP=true
incorr 🔒  Middleware Incorruptible.Chk cookie DevMode= true
incorr 🔒  Middleware Incorruptible.Chk cookie DevMode= true
incorr 🔒  Middleware Incorruptible.Chk cookie DevMode= true
incorr 🔒  Middleware Incorruptible.Chk cookie DevMode= true
garcon ℹ️  Middleware WebForm redirects to http://localhost:8080/myapp
garcon ℹ️  empty URL => use the LogNotifier
incorr 🔒  Middleware Incorruptible.Set cookie "myapp" MaxAge=60 setIP=true
incorr 🔒  Middleware Incorruptible.Vet cookie/bearer DevMode= true
incorr 🔒  Middleware Incorruptible.Vet cookie/bearer DevMode= true
incorr 🔒  Middleware Incorruptible.Vet cookie/bearer DevMode= true
garcon ℹ️  MiddlewareLogDurationSafe: logs requester IP, sanitized URL and duration
garcon ℹ️  MiddlewareServerHeader sets the HTTP header Server=MyApp-devel in the responses
garcon ℹ️  MiddlewareRateLimiter burst=40 rate=2.67/s
garcon ℹ️  MiddlewareLogFingerprint: 
1. Accept-Language, the language preferred by the user. 
2. User-Agent, name and version of the browser and OS. 
3. R=Referer, the website from which the request originated. 
4. A=Accept, the content types the browser prefers. 
5. E=Accept-Encoding, the compression formats the browser supports. 
6. Connection, can be empty, "keep-alive" or "close". 
7. Cache-Control, how the browser is caching data. 
8. URI=Upgrade-Insecure-Requests, the browser can upgrade from HTTP to HTTPS. 
9. Via avoids request loops and identifies protocol capabilities. 
10. Authorization or Cookie (both should not be present at the same time). 
11. DNT (Do Not Track) is being dropped by web browsers.
garcon ℹ️  MiddlewareRejectUnprintableURI rejects URI having line breaks or unprintable characters
app    🎬  -------------- Open http://localhost:8080/myapp --------------
garcon 📰  Server listening on http://localhost:8080
2. Embedded PProf server

Visit the PProf server at http://localhost:8093/debug/pprof providing the following endpoints:

PProf is easy to use with curl or wget:

( cd ~ ; go get -u github.com/google/pprof )

curl http://localhost:8093/debug/pprof/allocs > allocs.pprof
pprof -http=: allocs.pprof

wget http://localhost:8093/debug/pprof/heap
pprof -http=: heap

wget http://localhost:8093/debug/pprof/goroutine
pprof -http=: goroutine

See the PProf post (2013) for further explanations.

3. Exporter server

To facilitate the prod management, metrics and health state are communicated. Tools like Prometheus and Kubernetes collect every N seconds this information depending on the endpoint:

Kubernetes uses that readiness status to orchestrate the deployment. The default update policy is to update one pod at a time: Kubernetes waits for the new pod to be ready to receive traffic before updating the next one.

4. Static website server

⚠ WARNING: This section is outdated! ⚠

The complete example is running.

Open http://localhost:8080/myapp with your browser, and play with the API endpoints.

The resources and API endpoints are protected with a HttpOnly cookie. The complete example sets the cookie to browsers visiting the index.html.

func handler(gw garcon.Writer, jc *jwtperm.Checker) http.Handler {
    r := chi.NewRouter()

    // Static website files
    ws := garcon.WebServer{Dir: "examples/www", Writer: gw}
    r.With(jc.SetCookie).Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))
    r.With(jc.SetCookie).Get("/favicon.ico", ws.ServeFile("favicon.ico", "image/x-icon"))
    r.With(jc.ChkCookie).Get("/js/*", ws.ServeDir("text/javascript; charset=utf-8"))
    r.With(jc.ChkCookie).Get("/css/*", ws.ServeDir("text/css; charset=utf-8"))
    r.With(jc.ChkCookie).Get("/images/*", ws.ServeImages())

    // API
    r.With(jc.ChkJWT).Get("/api/v1/items", items)
    r.With(jc.ChkJWT).Get("/api/v1/ducks", gw.NotImplemented)

    // Other endpoints
    r.NotFound(gw.InvalidPath)

    return r
}
5. Enable Authentication

⚠ WARNING: This section is outdated! ⚠

Restart again the complete example with authentication enabled.

Attention, in this example we use two redundant middleware pieces using the same JWT: jwtperm and opa. This is just an example, don't be confused.

go run -race ./examples/complete -auth

2021/12/02 08:09:47 Prometheus export http://localhost:9093
2021/12/02 08:09:47 CORS: Set origin prefixes: [http://localhost:8080 http://localhost: http://192.168.1.]
2021/12/02 08:09:47 CORS: Methods=[GET] Headers=[Origin Accept Content-Type Authorization Cookie] Credentials=true MaxAge=86400
2021/12/02 08:09:47 JWT not required for dev. origins: [http://localhost:8080 http://localhost: http://192.168.1.]
2021/12/02 08:09:47 Enable PProf endpoints: http://localhost:8093/debug/pprof
2021/12/02 08:09:47 Create cookie plan=FreePlan domain=localhost secure=false jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuIjoiRnJlZVBsYW4iLCJleHAiOjE2Njk5NjQ5ODd9.5tJk2NoHxkG0o_owtMleBcUaR8z1vRx4rxRRqtZUc_Q
2021/12/02 08:09:47 Create cookie plan=PremiumPlan domain=localhost secure=false jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuIjoiUHJlbWl1bVBsYW4iLCJleHAiOjE2Njk5NjQ5ODd9.ifKhbmxQQ64NweL5aQDb_42tvKHwqiEKD-vxHO3KzsM
2021/12/02 08:09:47 OPA: load "examples/sample-auth.rego"
2021/12/02 08:09:47 Middleware OPA: map[sample-auth.rego:package auth

default allow = false
tokens := {"Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuIjoiRnJlZVBsYW4iLCJleHAiOjE2Njk5NjQ0ODh9.elDm_t4vezVgEmS8UFFo_spLJTts7JWybzbyO_aYV3Y"} { true }
allow = true { __local0__ = input.token; data.auth.tokens[__local0__] }]
2021/12/02 08:09:47 Middleware response HTTP header: Set Server MyBackendName-1.2.0
2021/12/02 08:09:47 MiddlewareRateLimiter burst=100 rate=5/s
2021/12/02 08:09:47 Middleware logger: requester IP and requested URL
2021/12/02 08:09:47 Server listening on http://localhost:8080
6. Default HTTP request headers

Test the API with curl:

curl -D - http://localhost:8080/myapp/api/v1/items

HTTP/1.1 401 Unauthorized
Content-Type: application/json
Server: MyBackendName-1.2.0
Vary: Origin
Date: Thu, 02 Dec 2021 07:06:20 GMT
Content-Length: 84

{"error":"Unauthorized",
"path":"/api/v1/items",
"doc":"http://localhost:8080/myapp/doc"}

The corresponding garcon logs:

2021/12/02 08:06:20 in  127.0.0.1:42888 GET /api/v1/items
[cors] 2021/12/02 08:06:20 Handler: Actual request
[cors] 2021/12/02 08:06:20   Actual request no headers added: missing origin
2021/12/02 08:06:20 OPA unauthorize 127.0.0.1:42888 /api/v1/items
2021/12/02 08:06:20 out 127.0.0.1:42888 GET /api/v1/items 1.426916ms c=1

The CORS logs can be disabled by passing debug=false in cors.Handler(origins, false).

The value c=1 measures the web traffic (current active HTTP connections).

7. With Authorization header
curl -D - http://localhost:8080/myapp/api/v1/items -H 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuIjoiRnJlZVBsYW4iLCJleHAiOjE2Njk5NjQ0ODh9.elDm_t4vezVgEmS8UFFo_spLJTts7JWybzbyO_aYV3Y'

HTTP/1.1 200 OK
Content-Type: application/json
Server: MyBackendName-1.2.0
Vary: Origin
Date: Thu, 02 Dec 2021 07:10:37 GMT
Content-Length: 25

["item1","item2","item3"]

The corresponding garcon logs:

2021/12/02 08:10:37 in  127.0.0.1:42892 GET /api/v1/items
[cors] 2021/12/02 08:10:37 Handler: Actual request
[cors] 2021/12/02 08:10:37   Actual request no headers added: missing origin
2021/12/02 08:10:37 Authorization header has JWT: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuIjoiRnJlZVBsYW4iLCJleHAiOjE2Njk5NjQ0ODh9.elDm_t4vezVgEmS8UFFo_spLJTts7JWybzbyO_aYV3Y
2021/12/02 08:10:37 JWT Claims: {FreePlan  {  [] 2022-12-02 08:01:28 +0100 CET <nil> <nil> invalid cookie}}
2021/12/02 08:10:37 JWT has the FreePlan Namespace
2021/12/02 08:10:37 JWT Permission: {10}
2021/12/02 08:10:37 out 127.0.0.1:42892 GET /api/v1/items 1.984568ms c=1 a=1 i=0 h=0

Low-level example

⚠ WARNING: This section is outdated! ⚠

See the low-level example.

The following code is a bit different to the stuff done by the complete function Garcon.Run() presented in the previous chapter. The following code is intended to show Garcon can be customized to meet your specific requirements.

package main

import (
    "log"
    "net"
    "net/http"
    "time"

    "github.com/go-chi/chi/v5"
    "github.com/teal-finance/garcon"
)

// Garcon settings
const apiDoc = "https://my-dns.co/doc"
const allowedProdOrigin = "https://my-dns.co"
const allowedDevOrigins = "http://localhost: http://192.168.1."
const serverHeader = "MyBackendName-1.2.0"
const authCfg = "examples/sample-auth.rego"
const pprofPort = 8093
const expPort = 9093
const burst, reqMinute = 10, 30
const devMode = true

func main() {
    if devMode {
        // the following line collects the CPU-profile and writes it in the file "cpu.pprof"
        defer garcon.ProbeCPU().Stop()
    }

    garcon.StartPProfServer(pprofPort)

    // Uniformize error responses with API doc
    gw := garcon.NewWriter(apiDoc)

    middleware, connState := setMiddlewares(gw)

    // Handles both REST API and static web files
    h := handler(gw)
    h = middleware.Then(h)

    runServer(h, connState)
}

func setMiddlewares(gw garcon.Writer) (middleware garcon.Chain, connState func(net.Conn, http.ConnState)) {
 // Start an exporter/health server in background if export port > 0.
 // This server is for use with Kubernetes and Prometheus-like monitoring tools.
    middleware, connState = garcon.StartExporter(expPort, devMode)

    // Limit the input request rate per IP
    reqLimiter := garcon.NewReqLimiter(gw, burst, reqMinute, devMode)

    corsConfig := allowedProdOrigin
    if devMode {
        corsConfig += " " + allowedDevOrigins
    }

    allowedOrigins := garcon.SplitClean(corsConfig)

    middleware = middleware.Append(
        reqLimiter.Limit,
        garcon.ServerHeader(serverHeader),
        cors.Handler(allowedOrigins, devMode),
    )

    // Endpoint authentication rules (Open Policy Agent)
    files := garcon.SplitClean(authCfg)
    policy, err := garcon.NewPolicy(gw, files)
    if err != nil {
        log.Fatal(err)
    }

    if policy.Ready() {
        middleware = middleware.Append(policy.Auth)
    }

    return middleware, connState
}

// runServer runs in foreground the main server.
func runServer(h http.Handler, connState func(net.Conn, http.ConnState)) {
    const mainPort = "8080"

    server := http.Server{
        Addr:              ":" + mainPort,
        Handler:           h,
        TLSConfig:         nil,
        ReadTimeout:       1 * time.Second,
        ReadHeaderTimeout: 1 * time.Second,
        WriteTimeout:      1 * time.Second,
        IdleTimeout:       1 * time.Second,
        MaxHeaderBytes:    222,
        TLSNextProto:      nil,
        ConnState:         connState,
        ErrorLog:          log.Default(),
        BaseContext:       nil,
        ConnContext:       nil,
    }

    log.Print("Server listening on http://localhost", server.Addr)

    log.Fatal(server.ListenAndServe())
}

// handler creates the mapping between the endpoints and the handler functions.
func handler(gw garcon.Writer) http.Handler {
    r := chi.NewRouter()

    // Website with static files
    ws := g.NewStaticWebServer("/var/www")
    r.Get("/", ws.ServeFile("index.html", "text/html; charset=utf-8"))
    r.Get("/js/*", ws.ServeDir("text/javascript; charset=utf-8"))
    r.Get("/css/*", ws.ServeDir("text/css; charset=utf-8"))
    r.Get("/images/*", ws.ServeImages())

    // API
    r.Get("/api/v1/items", items)
    r.Get("/api/v1/ducks", gw.NotImplemented)

    // Other endpoints
    r.NotFound(gw.InvalidPath)

    return r
}

func items(w http.ResponseWriter, _ *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    w.Write([]byte(`["item1","item2","item3"]`))
}

KeyStore example

The example KeyStore implements a key/value datastore providing private storage for each client identified by its unique IP.

cd garcon
go run -race ./examples/keystore

Then open http://localhost:8080 to learn more about the implemented features.

✨ Contributions Welcome

This project needs your help to become better. Please propose your enhancements, or even a further refactoring.

We welcome contributions in many forms, and there's always plenty to do!

🗣️ Feedback

If you have some suggestions, or need a new feature, please contact us, using the issues, or at Teal.Finance@pm.me or @TealFinance.

Feel free to propose a Pull Request, your contributions are welcome. 😉

Copyright (c) 2021 Teal.Finance/Garcon contributors

Teal.Finance/Garcon is free software, and can be redistributed and/or modified under the terms of the MIT License. SPDX-License-Identifier: MIT

Teal.Finance/Garcon is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the LICENSE file (alongside the source files) or https://opensource.org/licenses/MIT.

See also

Documentation

Overview

Package garcon is a server for API and static website including middlewares to manage rate-limit, Cookies, JWT, CORS, OPA, web traffic, Prometheus export and PProf.

Index

Constants

View Source 
const (
	DefaultCookieName = "g" // g as in garcon
	// DefaultPlan is the plan name in absence of "permissions" parametric parameters.
	DefaultPlan = "VIP"
	// DefaultPerm is the perm value in absence of "permissions" parametric parameters.
	DefaultPerm = 1
)
View Source 
const FingerprintExplanation = `` /* 683-byte string literal not displayed */

FingerprintExplanation provides a description of the logged HTTP headers.

Variables

View Source 
var (
	ErrExpiredToken    = errors.New("expired or invalid access token")
	ErrJWTSignature    = errors.New("JWT signature mismatch")
	ErrNoAuthorization = errors.New("provide your JWT within the 'Authorization Bearer' HTTP header")
	ErrNoBase64JWT     = errors.New("the token claims (second part of the JWT) is not base64-valid")
	ErrNoBearer        = errors.New("malformed HTTP Authorization, must be Bearer")
	ErrNoValidJWT      = errors.New("cannot find a valid JWT in either the cookie or the first 'Authorization' HTTP header")
)
View Source 
var V string

V is set at build time using the `-ldflags` build flag: 

v="$(git describe --tags --always --broken)"
go build -ldflags="-X 'github.com/teal-finance/garcon.V=$v'" ./cmd/main/package

The following commands provide a semver-like version format such as "v1.2.0-my-branch+3" where "+3" is the number of commits since "v1.2.0". If no tag in the Git repo, $t is the long SHA1 of the last commit. 

t="$(git describe --tags --abbrev=0 --always)"
b="$(git branch --show-current)"
[ _$b = _main ] && b="" || b="-$b"
n="$(git rev-list --count "$t"..)"
[ "$n" -eq 0 ] && n="" || n="+$n"
go build -ldflags="-X 'github.com/teal-finance/garcon.V=$t$b$n'" ./cmd/main/package

Functions

func DefaultContactSettings added in v0.16.0 

func DefaultContactSettings() map[string][2]int

DefaultContactSettings is compliant with standard names for web form input fields: https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#inappropriate-for-the-control

func DefaultFileSettings added in v0.16.0 

func DefaultFileSettings() map[string][2]int

DefaultFileSettings sets FileLimits with only "file".

func DevOrigins added in v0.4.3 

func DevOrigins() []*url.URL

DevOrigins provides the development origins: - yarn run vite --port 3000 - yarn run vite preview --port 5000 - localhost:8085 on multi devices: web auto-reload using https://github.com/synw/fwr - flutter run --web-port=8080 - 192.168.1.x + any port on tablet: mobile app using fast builtin auto-reload.

func FingerprintMD added in v0.17.0 

func FingerprintMD(r *http.Request) string

FingerprintMD provide the browser fingerprint in markdown format. Attention: read the .

func InsertSchema added in v0.17.0 

func InsertSchema(urls []string)

InsertSchema inserts "http://" when HTTP schema is missing.

func InvalidPath added in v0.17.0 

func InvalidPath(w http.ResponseWriter, r *http.Request)

func ListenAndServe added in v0.23.0 

func ListenAndServe(server *http.Server) error

ListenAndServe runs the HTTP server(s) in foreground. Optionally it also starts an exporter health server in background (if export port > 0). The exporter health server is for use with Kubernetes and Prometheus-like monitoring tools.

func LogVersion added in v0.20.0 

func LogVersion()

LogVersion logs the version and (Git) commit information.

func MiddlewareCORS added in v0.23.0 

func MiddlewareCORS(allowedOrigins, methods, headers []string, debug bool) func(next http.Handler) http.Handler

MiddlewareCORS uses restrictive CORS values.

func MiddlewareLogDuration added in v0.23.0 

func MiddlewareLogDuration(next http.Handler) http.Handler

MiddlewareLogDuration logs the requested URL along with the time to handle it.

func MiddlewareLogDurationSafe added in v0.23.0 

func MiddlewareLogDurationSafe(next http.Handler) http.Handler

MiddlewareLogDurationSafe is similar to MiddlewareLogDurations but also sanitizes the URL.

func MiddlewareLogFingerprint added in v0.23.0 

func MiddlewareLogFingerprint(next http.Handler) http.Handler

MiddlewareLogFingerprint is the middleware to log incoming HTTP request and browser fingerprint.

func MiddlewareLogFingerprintSafe added in v0.23.0 

func MiddlewareLogFingerprintSafe(next http.Handler) http.Handler

MiddlewareLogFingerprintSafe is similar to MiddlewareLogFingerprints but sanitize the URL.

func MiddlewareLogRequest added in v0.23.0 

func MiddlewareLogRequest(next http.Handler) http.Handler

MiddlewareLogRequest is the middleware to log the requester IP and the requested URL.

func MiddlewareLogRequestSafe added in v0.23.0 

func MiddlewareLogRequestSafe(next http.Handler) http.Handler

MiddlewareLogRequestSafe is similar to LogRequest but sanitize the URL.

func MiddlewareRejectUnprintableURI added in v0.23.0 

func MiddlewareRejectUnprintableURI(next http.Handler) http.Handler

MiddlewareRejectUnprintableURI is a middleware rejecting HTTP requests having a Carriage Return "\r" or a Line Feed "\n" within the URI to prevent log injection.

func MiddlewareSecureHTTPHeader added in v0.23.0 

func MiddlewareSecureHTTPHeader(secure bool) func(next http.Handler) http.Handler

MiddlewareSecureHTTPHeader is a middleware adding recommended HTTP response headers to secure the web application.

func MiddlewareServerHeader added in v0.23.0 

func MiddlewareServerHeader(version string) func(next http.Handler) http.Handler

MiddlewareServerHeader is the middleware setting the Server HTTP header in the response.

func NewAccessToken added in v0.26.0 

func NewAccessToken(maxTTL, user string, groups, orgs []string, hexKey string) string

func NewCookie added in v0.30.0 

func NewCookie(tokenizer tokens.Tokenizer, name, plan, user string, secure bool, dns, dir string) http.Cookie

func NotImplemented added in v0.17.0 

func NotImplemented(w http.ResponseWriter, r *http.Request)

func PrintVersionAndExit added in v0.31.0 

func PrintVersionAndExit(program string)

PrintVersionAndExit prints the version and exits. The version may also contain the (Git) commit information.

func ProbeCPU added in v0.17.0 

func ProbeCPU() interface{ Stop() }

ProbeCPU is used like the following: 

defer pprof.ProbeCPU.Stop()

When the caller reaches its function end, the defer executes Stop() that writes the file "cpu.pprof". To visualize "cpu.pprof" use the pprof tool: 

cd ~/go
go get -u github.com/google/pprof
cd -
pprof -http=: cpu.pprof

or using one single command line: 

go run github.com/google/pprof@latest -http=: cpu.pprof

func ServeVersion added in v0.22.0 

func ServeVersion() func(w http.ResponseWriter, r *http.Request)

ServeVersion send HTML or JSON depending on Accept header.

func Server added in v0.23.0 

func Server(h http.Handler, port int, connState ...func(net.Conn, http.ConnState)) http.Server

Server returns a default http.Server ready to handle API endpoints, static web pages...

func SetCustomVersionFlag added in v0.20.0 

func SetCustomVersionFlag(fs *flag.FlagSet, flagName, program string)

SetCustomVersionFlag register PrintVersionAndExit() for the -version flag.

Example with default values: 

import "github.com/teal-finance/garcon"

func main() {
     garcon.SetCustomVersionFlag(nil, "", "")
     flag.Parse()
}

Example with custom values values: 

import "github.com/teal-finance/garcon"

func main() {
     garcon.SetCustomVersionFlag(nil, "v", "MyApp")
     flag.Parse()
}

func SetVersionFlag added in v0.17.0 

func SetVersionFlag()

SetVersionFlag defines -version flag to print the version stored in V. See SetCustomVersionFlag for a more flexibility.

func StartExporter added in v0.33.0 

func StartExporter(port int, namespace ServerName, options ...ProbeOption) (gg.Chain, func(net.Conn, http.ConnState))

StartExporter creates and starts the exporter health server for Prometheus metrics and liveness/readiness endpoints.

func StartPProfServer added in v0.17.0 

func StartPProfServer(port int)

StartPProfServer starts a PProf server in background. Endpoints usage example: 

curl http://localhost:6063/debug/pprof/allocs > allocs.pprof
pprof -http=: allocs.pprof

wget http://localhost:31415/debug/pprof/goroutine
pprof -http=: goroutine

wget http://localhost:31415/debug/pprof/heap
pprof -http=: heap

wget http://localhost:31415/debug/pprof/trace
pprof -http=: trace

func StatusCodeStr added in v0.28.0 

func StatusCodeStr(code int) string

func Version added in v0.17.0 

func Version(serverName string) string

Version format is "Program-1.2.3". If the program argument is empty, the format is "v1.2.3". If V is empty, Version uses the main module version.

func WriteErr added in v0.21.0 

func WriteErr(w http.ResponseWriter, r *http.Request, statusCode int, kv ...any)

func WriteOK added in v0.21.0 

func WriteOK(w http.ResponseWriter, kv ...any)

Types

type AdaptiveRate added in v0.24.0 

type AdaptiveRate struct {
	Name      string
	NextSleep time.Duration
	MinSleep  time.Duration
}

AdaptiveRate continuously adjusts the timing between requests to prevent the API responds "429 Too Many Requests". AdaptiveRate increases/decreases the rate depending on absence/presence of the 429 status code.

func NewAdaptiveRate added in v0.24.0 

func NewAdaptiveRate(name string, d time.Duration) AdaptiveRate

func (*AdaptiveRate) Get added in v0.24.0 

func (ar *AdaptiveRate) Get(symbol, url string, msg any, maxBytes ...int) error

func (*AdaptiveRate) LogStats added in v0.24.0 

func (ar *AdaptiveRate) LogStats()

type Garcon 

type Garcon struct {
	ServerName ServerName
	Writer     Writer
	// contains filtered or unexported fields
}

func New added in v0.6.0 

func New(opts ...Option) *Garcon

func (*Garcon) IncorruptibleChecker added in v0.23.0 

func (g *Garcon) IncorruptibleChecker(secretKeyHex string, maxAge int, setIP bool) *incorruptible.Incorruptible

IncorruptibleChecker uses cookies based the fast and tiny Incorruptible token. IncorruptibleChecker requires g.WithURLs() to set the Cookie secure, domain and path.

func (*Garcon) IncorruptibleCheckerBin added in v0.27.0 

func (g *Garcon) IncorruptibleCheckerBin(secretKeyBin []byte, maxAge int, setIP bool) *incorruptible.Incorruptible

IncorruptibleChecker uses cookies based the fast and tiny Incorruptible token. IncorruptibleChecker requires g.WithURLs() to set the Cookie secure, domain and path.

func (Garcon) IsDevMode added in v0.26.1 

func (g Garcon) IsDevMode() bool

func (*Garcon) JWTChecker added in v0.6.0 

func (g *Garcon) JWTChecker(keyTxt string, planPerm ...any) *JWTChecker

JWTChecker requires WithURLs() to set the Cookie name, secure, domain and path. The keyTxt can be in hexadecimal or Base64, and can also be prefixed by the wanted signing algorithm. The keyTxt scheme is: `alg:xxxxxxxxxxxxxxxxxxxxxxxxxx` where `alg` is the optional algorithm name, and `xxxxxxxxxxxxxxxxxxxxxxxxxx` is the key encoded in either hexadecimal or unpadded Base64 as defined in RFC 4648 §5 (URL encoding).

func (*Garcon) MiddlewareCORS added in v0.23.0 

func (g *Garcon) MiddlewareCORS() gg.Middleware

MiddlewareCORS is a middleware to handle Cross-Origin Resource Sharing (CORS).

func (*Garcon) MiddlewareCORSWithMethodsHeaders added in v0.23.3 

func (g *Garcon) MiddlewareCORSWithMethodsHeaders(methods, headers []string) gg.Middleware

MiddlewareCORSWithMethodsHeaders is a middleware to handle Cross-Origin Resource Sharing (CORS).

func (*Garcon) MiddlewareLogDuration added in v0.23.0 

func (g *Garcon) MiddlewareLogDuration(safe ...bool) gg.Middleware

MiddlewareLogDuration logs the requested URL along with its handling time. When the optional parameter safe is true, this middleware sanitizes the URL before printing it.

func (*Garcon) MiddlewareLogRequest added in v0.23.0 

func (g *Garcon) MiddlewareLogRequest(settings ...string) gg.Middleware

MiddlewareLogRequest logs the incoming request URL. If one of its optional parameter is "fingerprint", this middleware also logs the browser fingerprint. If the other optional parameter is "safe", this middleware sanitizes the URL before printing it.

func (*Garcon) MiddlewareRateLimiter added in v0.23.0 

func (g *Garcon) MiddlewareRateLimiter(settings ...int) gg.Middleware

func (Garcon) MiddlewareRejectUnprintableURI added in v0.23.0 

func (Garcon) MiddlewareRejectUnprintableURI() gg.Middleware

MiddlewareRejectUnprintableURI is a middleware rejecting HTTP requests having a Carriage Return "\r" or a Line Feed "\n" within the URI to prevent log injection.

func (*Garcon) MiddlewareServerHeader added in v0.23.0 

func (g *Garcon) MiddlewareServerHeader(serverName ...string) gg.Middleware

func (*Garcon) NewContactForm added in v0.22.0 

func (g *Garcon) NewContactForm(redirectURL string) WebForm

func (*Garcon) NewStaticWebServer added in v0.23.0 

func (g *Garcon) NewStaticWebServer(dir string) StaticWebServer

NewStaticWebServer creates a StaticWebServer.

func (*Garcon) StartExporter added in v0.33.0 

func (g *Garcon) StartExporter(expPort int, options ...ProbeOption) (gg.Chain, func(net.Conn, http.ConnState))

StartExporter creates and starts the exporter health server (Kubernetes health endpoints and Prometheus export server).

type JWTChecker added in v0.20.0 

type JWTChecker struct {
	// contains filtered or unexported fields
}

func NewJWTChecker added in v0.20.0 

func NewJWTChecker(gw Writer, urls []*url.URL, keyTxt, cookieName string, permissions ...any) *JWTChecker

NewJWTChecker supports keyTxt in hexadecimal and Base64 form Moreover the keyTxt parameter can also be prefixed by the signing algorithm. The keyTxt scheme is: `alg:xxxxxxxxxxxxxxxxxxxxxxxxxx` where `alg` is the optional algorithm name, and `xxxxxxxxxxxxxxxxxxxxxxxxxx` is the key encoded in either hexadecimal or unpadded Base64 as defined in RFC 4648 §5 (URL encoding).

func (*JWTChecker) Chk added in v0.20.0 

func (ck *JWTChecker) Chk(next http.Handler) http.Handler

Chk is a middleware to accept only HTTP requests having a valid cookie. Then, Chk puts the permission (of the JWT) in the request context.

func (*JWTChecker) Cookie added in v0.20.0 

func (ck *JWTChecker) Cookie(i int) *http.Cookie

Cookie returns a default cookie to facilitate testing.

func (*JWTChecker) PermFromBearerOrCookie added in v0.20.0 

func (ck *JWTChecker) PermFromBearerOrCookie(r *http.Request) (perm Perm, err []any)

func (*JWTChecker) PermFromCookie added in v0.20.0 

func (ck *JWTChecker) PermFromCookie(r *http.Request) (perm Perm, err []any)

func (*JWTChecker) PermFromJWT added in v0.20.0 

func (ck *JWTChecker) PermFromJWT(jwt string) (Perm, []any)

func (*JWTChecker) Set added in v0.20.0 

func (ck *JWTChecker) Set(next http.Handler) http.Handler

Set is a middleware putting a HttpOnly cookie in the HTTP response header when no valid cookie is present. The new cookie conveys the JWT of the first plan. Set also puts the permission from the JWT in the request context.

func (*JWTChecker) Vet added in v0.20.0 

func (ck *JWTChecker) Vet(next http.Handler) http.Handler

Vet is a middleware to accept only the HTTP request having a valid JWT. The JWT can be either in the cookie or in the first "Authorization" header. Then, Vet puts the permission (of the JWT) in the request context.

type Muter added in v0.21.0 

type Muter struct {
	// Threshold is the level enabling the muted state.
	Threshold int

	// NoAlertDuration allows to consider the verbosity is back to normal.
	NoAlertDuration time.Duration

	// RemindMuteState allows to remind the state is still muted.
	// Set value 100 to send this reminder every 100 increments.
	// Set to zero to disable this feature,
	RemindMuteState int
	// contains filtered or unexported fields
}

Muter can be used to limit the logger/alerting verbosity. Muter detects when its internal counter is over the Threshold and waits the counter goes back to zero or after NoAlertDuration to return to normal situation. Muter uses the Hysteresis principle: https://wikiless.org/wiki/Hysteresis Similar wording: quieter, stopper, limiter, reducer, inhibitor, mouth-closer.

func (*Muter) Decrement added in v0.21.0 

func (m *Muter) Decrement() (ok bool, _ time.Time, dropped int)

Decrement decrements the internal counter and switches to un-muted state when counter reaches zero or after NoAlertDuration.

func (*Muter) Increment added in v0.21.0 

func (m *Muter) Increment() (ok bool, dropped int)

Increment increments the internal counter and returns false when in muted state. Every RemindMuteState calls, Increment also returns the number of times Increment has been called.

type Option added in v0.6.0 

type Option func(*Garcon)

func WithDev added in v0.6.0 

func WithDev(enable ...bool) Option

func WithDocURL added in v0.6.0 

func WithDocURL(docURL string) Option

func WithPProf added in v0.6.0 

func WithPProf(port int) Option

func WithServerName added in v0.23.0 

func WithServerName(str string) Option

func WithURLs added in v0.9.0 

func WithURLs(addresses ...string) Option

type Perm added in v0.17.0 

type Perm struct {
	Value int
}

func PermFromCtx added in v0.20.0 

func PermFromCtx(r *http.Request) Perm

PermFromCtx gets the permission information from the request context.

func (Perm) PutInCtx added in v0.20.0 

func (perm Perm) PutInCtx(r *http.Request) *http.Request

PutInCtx stores the permission info within the request context.

type ProbeFunction added in v0.33.0 

type ProbeFunction func() []byte

ProbeFunction returns a JSON text explaining the health issue. If the health status is OK, returns nothing (an empty text).

type ProbeOption added in v0.33.0 

type ProbeOption func(*exporterHandler)

func WithLivenessProbes added in v0.33.0 

func WithLivenessProbes(probes ...ProbeFunction) ProbeOption

WithLivenessProbes adds given liveness probes to the set of probes.

func WithReadinessProbes added in v0.33.0 

func WithReadinessProbes(probes ...ProbeFunction) ProbeOption

WithReadinessProbes adds given readiness probes to the set of probes.

type ReqLimiter added in v0.17.0 

type ReqLimiter struct {
	// contains filtered or unexported fields
}

func NewRateLimiter added in v0.23.0 

func NewRateLimiter(gw Writer, maxReqBurst, maxReqPerMinute int, devMode bool) ReqLimiter

func (*ReqLimiter) MiddlewareRateLimiter added in v0.23.0 

func (rl *ReqLimiter) MiddlewareRateLimiter(next http.Handler) http.Handler

type ServerName added in v0.23.0 

type ServerName string

ServerName is used in multiple parts in Garcon: - the HTTP Server header, - the Prometheus namespace.

func (ServerName) ConnState added in v0.33.0 

func (ns ServerName) ConnState() func(net.Conn, http.ConnState)

ConnState counts the HTTP connections and update web traffic metrics depending on incoming requests and outgoing responses.

func (ServerName) MiddlewareExportTrafficMetrics added in v0.23.0 

func (ns ServerName) MiddlewareExportTrafficMetrics(next http.Handler) http.Handler

MiddlewareExportTrafficMetrics measures the duration to process a request.

func (ServerName) RespectPromNamingRule added in v0.33.0 

func (ns ServerName) RespectPromNamingRule() ServerName

RespectPromNamingRule verifies Prom naming rules for namespace and fixes it if necessary. valid namespace = [a-zA-Z][a-zA-Z0-9_]* https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels

func (ServerName) String added in v0.23.0 

func (ns ServerName) String() string

type StaticWebServer added in v0.16.0 

type StaticWebServer struct {
	Writer Writer
	Dir    string
}

StaticWebServer is a webserver serving static files among HTML, CSS, JS and popular image formats.

func NewStaticWebServer added in v0.16.0 

func NewStaticWebServer(gw Writer, dir string) StaticWebServer

NewStaticWebServer creates a StaticWebServer.

func (*StaticWebServer) ServeAssets added in v0.16.0 

func (ws *StaticWebServer) ServeAssets() func(w http.ResponseWriter, r *http.Request)

ServeAssets detects the Content-Type depending on the asset extension.

func (*StaticWebServer) ServeDir added in v0.16.0 

func (ws *StaticWebServer) ServeDir(contentType string) func(w http.ResponseWriter, r *http.Request)

ServeDir handles the static files using the same Content-Type.

func (*StaticWebServer) ServeFile added in v0.16.0 

func (ws *StaticWebServer) ServeFile(urlPath, contentType string) func(w http.ResponseWriter, r *http.Request)

ServeFile handles one specific file (and its specific Content-Type).

func (*StaticWebServer) ServeImages added in v0.16.0 

func (ws *StaticWebServer) ServeImages() func(w http.ResponseWriter, r *http.Request)

ServeImages detects the Content-Type depending on the image extension.

type TokenChecker added in v0.13.0 

type TokenChecker interface {
	// Set is a middleware setting a cookie in the response when the request has no valid token.
	// Set searches the token in a cookie and in the first "Authorization" header.
	// Finally, Set stores the decoded token fields within the request context.
	Set(next http.Handler) http.Handler

	// Chk is a middleware accepting requests only if it has a valid cookie:
	// other requests are rejected with http.StatusUnauthorized.
	// Chk does not verify the "Authorization" header.
	// See also the Vet() function if the token should also be verified in the "Authorization" header.
	// Finally, Chk stores the decoded token fields within the request context.
	// In dev. mode, Chk accepts any request but does not store invalid tokens.
	Chk(next http.Handler) http.Handler

	// Vet is a middleware accepting requests having a valid token
	// either in the cookie or in the first "Authorization" header:
	// other requests are rejected with http.StatusUnauthorized.
	// Vet also stores the decoded token in the request context.
	// In dev. mode, Vet accepts any request but does not store invalid tokens.
	Vet(next http.Handler) http.Handler

	// Cookie returns a default cookie to facilitate testing.
	Cookie(i int) *http.Cookie
}

TokenChecker is the common interface to Incorruptible and JWTChecker.

type WebForm added in v0.16.0 

type WebForm struct {
	Writer   Writer
	Notifier gg.Notifier
	Redirect string

	// TextLimits are used as security limits
	// to avoid being flooded by large web forms
	// and unexpected field names.
	// The map key is the input field name.
	// The map value is a pair of integers:
	// the max length and the max line breaks.
	// Zero (or negative) value for unlimited value size.
	TextLimits map[string][2]int

	// FileLimits is similar to TextLimits
	// but for uploaded files.
	// The map value is a pair of integers:
	// the max size in runes of one file
	// and the max occurrences having same field name.
	// Zero (or negative) value for unlimited file size.
	FileLimits map[string][2]int

	// MaxBodyBytes limits someone hogging the host resources.
	// Zero (or negative) value disables this security check.
	MaxBodyBytes int64

	// MaxMDBytes includes the form fields and browser fingerprints.
	// Zero (or negative) value disables this security check.
	MaxMDBytes int
	// contains filtered or unexported fields
}

func NewContactForm added in v0.16.0 

func NewContactForm(gw Writer, redirectURL string) WebForm

NewContactForm initializes a new WebForm with the default contact-form settings.

func (*WebForm) Notify added in v0.23.0 

func (wf *WebForm) Notify(notifierURL string) func(w http.ResponseWriter, r *http.Request)

Notify returns a handler that converts the received web-form into markdown format and sends it to the notifierURL.

type Writer added in v0.21.0 

type Writer string

Writer enables writing useful JSON error message in the HTTP response body.

func NewWriter added in v0.21.0 

func NewWriter(docURL string) Writer

NewWriter creates a Writer structure.

func (Writer) InvalidPath added in v0.21.0 

func (gw Writer) InvalidPath(w http.ResponseWriter, r *http.Request)

func (Writer) NotImplemented added in v0.21.0 

func (gw Writer) NotImplemented(w http.ResponseWriter, r *http.Request)

func (Writer) TraversalPath added in v0.30.0 

func (gw Writer) TraversalPath(w http.ResponseWriter, r *http.Request) bool

TraversalPath returns true when path contains ".." to prevent path traversal attack.

func (Writer) WriteErr added in v0.21.0 

func (gw Writer) WriteErr(w http.ResponseWriter, r *http.Request, statusCode int, kv ...any)

WriteErr is a fast pretty-JSON marshaler dedicated to the HTTP error response. WriteErr extends the JSON content when more than two key-values (kv) are provided.

func (Writer) WriteOK added in v0.21.0 

func (gw Writer) WriteOK(w http.ResponseWriter, kv ...any)

WriteOK is a fast pretty-JSON marshaler dedicated to the HTTP successful response.

Source Files

View all Source files

Directories

Path Synopsis
cmd
reco
Package main converts a S2-compressed file to a Brotli one.
 Package main converts a S2-compressed file to a Brotli one.
examples
chi
complete
httprouter
keystore
low-level
rate-limiter
this example is an adapation of thise usage: https://github.com/teal-finance/rainbow/blob/main/pkg/provider/deribit/deribit.go
 this example is an adapation of thise usage: https://github.com/teal-finance/rainbow/blob/main/pkg/provider/deribit/deribit.go
Package gg is the Garcon toolbox.
 Package gg is the Garcon toolbox.
Package timex extends the standard package time.
 Package timex extends the standard package time.

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