GoMetric/statsd-http-proxy

package main

import (
    "flag"
    "fmt"
    "log"
    "net/http"
    _ "net/http/pprof"
    "os"
    "runtime"

    "github.com/GoMetric/statsd-http-proxy/proxy"
)

// Version is a current git commit hash and tag
// Injected by compilation flag
var Version = "Unknown"

// BuildNumber is a current commit hash
// Injected by compilation flag
var BuildNumber = "Unknown"

// BuildDate is a date of build
// Injected by compilation flag
var BuildDate = "Unknown"

// HTTP connection params
const defaultHTTPHost = "127.0.0.1"
const defaultHTTPPort = 8825
const defaultHTTPReadTimeout = 1
const defaultHTTPWriteTimeout = 1
const defaultHTTPIdleTimeout = 1

// StatsD connection params
const defaultStatsDHost = "127.0.0.1"
const defaultStatsDPort = 8125

func main() {
    // declare command line options
    var httpHost = flag.String("http-host", defaultHTTPHost, "HTTP Host")
    var httpPort = flag.Int("http-port", defaultHTTPPort, "HTTP Port")
    var httpReadTimeout = flag.Int("http-timeout-read", defaultHTTPReadTimeout, "The maximum duration in seconds for reading the entire request, including the body")
    var httpWriteTimeout = flag.Int("http-timeout-write", defaultHTTPWriteTimeout, "The maximum duration in seconds before timing out writes of the respons")
    var httpIdleTimeout = flag.Int("http-timeout-idle", defaultHTTPIdleTimeout, "The maximum amount of time in seconds to wait for the next request when keep-alives are enabled")
    var tlsCert = flag.String("tls-cert", "", "TLS certificate to enable HTTPS")
    var tlsKey = flag.String("tls-key", "", "TLS private key  to enable HTTPS")
    var statsdHost = flag.String("statsd-host", defaultStatsDHost, "StatsD Host")
    var statsdPort = flag.Int("statsd-port", defaultStatsDPort, "StatsD Port")
    var metricPrefix = flag.String("metric-prefix", "", "Prefix of metric name")
    var tokenSecret = flag.String("jwt-secret", "", "Secret to encrypt JWT")
    var verbose = flag.Bool("verbose", false, "Verbose")
    var version = flag.Bool("version", false, "Show version")
    var httpRouterName = flag.String("http-router-name", "HttpRouter", "Type of HTTP router. Allowed values are GorillaMux and HttpRouter. Do not use in production.")
    var statsdClientName = flag.String("statsd-client-name", "GoMetric", "Type of StatsD client. Allowed values are Cactus and GoMetric. Do not use in production.")
    var profilerHTTPort = flag.Int("profiler-http-port", 0, "Start profiler localhost")

    // get flags
    flag.Parse()

    // show version and exit
    if *version {
        fmt.Printf(
            "StatsD HTTP Proxy v.%s, build %s from %s\n",
            Version,
            BuildNumber,
            BuildDate,
        )
        os.Exit(0)
    }

    // log build version
    log.Printf(
        "Starting StatsD HTTP Proxy v.%s, build %s from %s\n",
        Version,
        BuildNumber,
        BuildDate,
    )

    // start profiler
    if *profilerHTTPort > 0 {
        // enable block profiling
        runtime.SetBlockProfileRate(1)

        // start debug server
        profilerHTTPAddress := fmt.Sprintf("localhost:%d", *profilerHTTPort)
        go func() {
            log.Println("Profiler started at " + profilerHTTPAddress)
            log.Println("Open 'http://" + profilerHTTPAddress + "/debug/pprof/' in you browser or use 'go tool pprof http://" + profilerHTTPAddress + "/debug/pprof/heap' from console")
            log.Println("See details about pprof in https://golang.org/pkg/net/http/pprof/")
            log.Println(http.ListenAndServe(profilerHTTPAddress, nil))
        }()
    }

    // start proxy server
    proxyServer := proxy.NewServer(
        *httpHost,
        *httpPort,
        *httpReadTimeout,
        *httpWriteTimeout,
        *httpIdleTimeout,
        *statsdHost,
        *statsdPort,
        *tlsCert,
        *tlsKey,
        *metricPrefix,
        *tokenSecret,
        *verbose,
        *httpRouterName,
        *statsdClientName,
    )

    proxyServer.Listen()
}