settings.go

package main

import (
	"flag"
	"fmt"
	"log"
	"os"
)

const (
	VERSION = "0.8"
)

type AppSettings struct {
	verbose bool
	stats   bool

	splitOutput bool

	inputDummy  MultiOption
	outputDummy MultiOption

	inputTCP  MultiOption
	outputTCP MultiOption

	inputFile  MultiOption
	outputFile MultiOption

	inputRAW MultiOption

	outputHTTP                  MultiOption
	outputHTTPHeaders           HTTPHeaders
	outputHTTPMethods           HTTPMethods
	outputHTTPUrlRegexp         HTTPUrlRegexp
	outputHTTPHeaderFilters     HTTPHeaderFilters
	outputHTTPHeaderHashFilters HTTPHeaderHashFilters
	outputHTTPElasticSearch     string
}

var Settings AppSettings = AppSettings{}

func usage() {
	fmt.Printf("Gor is a simple http traffic replication tool written in Go. Its main goal is to replay traffic from production servers to staging and dev environments.\nProject page: https://github.com/buger/gor\nAuthor: <Leonid Bugaev> leonsbox@gmail.com\nCurrent Version: %s\n\n", VERSION)
	flag.PrintDefaults()
	os.Exit(2)
}

func init() {
	flag.Usage = usage

	flag.BoolVar(&Settings.verbose, "verbose", false, "Turn on verbose/debug output")
	flag.BoolVar(&Settings.stats, "stats", false, "Turn on queue stats output")

	flag.BoolVar(&Settings.splitOutput, "split-output", false, "By default each output gets same traffic. If set to `true` it splits traffic equally among all outputs.")

	flag.Var(&Settings.inputDummy, "input-dummy", "Used for testing outputs. Emits 'Get /' request every 1s")
	flag.Var(&Settings.outputDummy, "output-dummy", "Used for testing inputs. Just prints data coming from inputs.")

	flag.Var(&Settings.inputTCP, "input-tcp", "Used for internal communication between Gor instances. Example: \n\t# Receive requests from other Gor instances on 28020 port, and redirect output to staging\n\tgor --input-tcp :28020 --output-http staging.com")
	flag.Var(&Settings.outputTCP, "output-tcp", "Used for internal communication between Gor instances. Example: \n\t# Listen for requests on 80 port and forward them to other Gor instance on 28020 port\n\tgor --input-raw :80 --output-tcp replay.local:28020")

	flag.Var(&Settings.inputFile, "input-file", "Read requests from file: \n\tgor --input-file ./requests.gor --output-http staging.com")
	flag.Var(&Settings.outputFile, "output-file", "Write incoming requests to file: \n\tgor --input-raw :80 --output-file ./requests.gor")

	flag.Var(&Settings.inputRAW, "input-raw", "Capture traffic from given port (use RAW sockets and require *sudo* access):\n\t# Capture traffic from 8080 port\n\tgor --input-raw :8080 --output-http staging.com")

	flag.Var(&Settings.outputHTTP, "output-http", "Forwards incoming requests to given http address.\n\t# Redirect all incoming requests to staging.com address \n\tgor --input-raw :80 --output-http http://staging.com")
	flag.Var(&Settings.outputHTTPHeaders, "output-http-header", "Inject additional headers to http reqest:\n\tgor --input-raw :8080 --output-http staging.com --output-http-header 'User-Agent: Gor'")
	flag.Var(&Settings.outputHTTPMethods, "output-http-method", "Whitelist of HTTP methods to replay. Anything else will be dropped:\n\tgor --input-raw :8080 --output-http staging.com --output-http-method GET --output-http-method OPTIONS")
	flag.Var(&Settings.outputHTTPUrlRegexp, "output-http-url-regexp", "A regexp to match requests against. Anything else will be dropped:\n\t gor --input-raw :8080 --output-http staging.com --output-http-url-regexp ^www.")
	flag.Var(&Settings.outputHTTPHeaderFilters, "output-http-header-filter", "A regexp to match a specific header against. Requests with non-matching headers will be dropped:\n\t gor --input-raw :8080 --output-http staging.com --output-http-header-filter api-version:^v1")
	flag.Var(&Settings.outputHTTPHeaderHashFilters, "output-http-header-hash-filter", "Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific header. The fraction must have a denominator that is a power of two:\n\t gor --input-raw :8080 --output-http staging.com --output-http-header-hash-filter user-id:1/4")

	flag.StringVar(&Settings.outputHTTPElasticSearch, "output-http-elasticsearch", "", "Send request and response stats to ElasticSearch:\n\tgor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'")
}

func Debug(args ...interface{}) {
	if Settings.verbose {
		log.Println(args...)
	}
}