main.go

package main

import (
	"bufio"
	"context"
	"io"
	"os"
	"os/signal"
	"strings"
	"syscall"

	"github.com/sirupsen/logrus"
	"github.com/tidwall/gjson"
	"golang.org/x/crypto/ssh/terminal"

	"github.com/batchcorp/plumber-schemas/build/go/protos/opts"

	"github.com/batchcorp/plumber/actions"
	"github.com/batchcorp/plumber/config"
	"github.com/batchcorp/plumber/kv"
	"github.com/batchcorp/plumber/options"
	"github.com/batchcorp/plumber/plumber"
	"github.com/batchcorp/plumber/printer"
	"github.com/batchcorp/plumber/prometheus"
)

func main() {
	kongCtx, cliOpts, err := options.New(os.Args[1:])
	if err != nil {
		logrus.Fatalf("Unable to handle CLI input: %s", err)
	}

	// TODO: STDIN write should be continuous; punting for now.
	readFromStdin(cliOpts)

	switch {
	case cliOpts.Global.Debug:
		logrus.SetLevel(logrus.DebugLevel)
	case cliOpts.Global.Quiet:
		logrus.SetLevel(logrus.ErrorLevel)
	}

	serviceCtx, serviceShutdownFunc := context.WithCancel(context.Background())
	mainShutdownCtx, mainShutdownFunc := context.WithCancel(context.Background())

	var k kv.IKV

	// If server && cluster mode is enabled, we should instantiate the kv store
	// so that the config is stored in NATS instead of disk.
	if cliOpts.Global.XAction == "server" && cliOpts.Server.EnableCluster {
		var err error

		k, err = kv.New(cliOpts.Server)
		if err != nil {
			logrus.Fatalf("unable to create KV store: %s", err)
		}
	}

	persistentConfig, err := config.New(cliOpts.Server.EnableCluster, k)
	if err != nil {
		logrus.Fatalf("unable to create persistent config: %s", err)
	}

	// Save config automatically on exit
	defer persistentConfig.Save()

	// We only want to intercept interrupt signals in relay or server mode
	if cliOpts.Global.XAction == "relay" || cliOpts.Global.XAction == "server" {
		logrus.Debug("Intercepting signals")

		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		signal.Notify(c, syscall.SIGTERM)

		go func() {
			sig := <-c
			logrus.Info("Shutting down plumber server...")
			logrus.Debugf("Received system call: %+v", sig)

			serviceShutdownFunc()
		}()

		// Create prometheus counters/gauges
		prometheus.InitPrometheusMetrics()
	}

	// TODO: This probably should be updated for server
	// Launch a dedicated goroutine if stats display is enabled
	if cliOpts.Relay != nil && cliOpts.Relay.StatsEnable {
		prometheus.Start(cliOpts.Relay.StatsReportIntervalSec)
	}

	// Force JSON and don't print logo when NOT in terminal (ie. in container, detached)
	if !terminal.IsTerminal(int(os.Stderr.Fd())) {
		logrus.SetFormatter(&logrus.JSONFormatter{})
	} else {
		printer.PrintLogo()
	}

	// Actions contains server-related methods that are used by both the gRPC
	// server and the etcd consumer.
	a, err := actions.New(&actions.Config{
		PersistentConfig: persistentConfig,
	})

	p, err := plumber.New(&plumber.Config{
		PersistentConfig:   persistentConfig,
		ServiceShutdownCtx: serviceCtx,
		KongCtx:            kongCtx,
		CLIOptions:         cliOpts,
		Actions:            a,
		MainShutdownFunc:   mainShutdownFunc,
		MainShutdownCtx:    mainShutdownCtx,
	})

	if err != nil {
		logrus.Fatal(err)
	}

	p.Run()
}

// readFromStdin reads data piped into stdin
func readFromStdin(opts *opts.CLIOptions) {
	info, err := os.Stdin.Stat()
	if err != nil {
		logrus.Fatal(err)
	}

	if info.Mode()&os.ModeCharDevice != 0 || info.Size() <= 0 {
		return
	}

	inputData := make([]string, 0)

	reader := bufio.NewReader(os.Stdin)
	for {
		line, err := reader.ReadBytes('\n')
		if err != nil && err == io.EOF {
			break
		}
		inputData = append(inputData, strings.Trim(string(line), "\n"))
	}

	// Treat input as a JSON array
	if opts.Write.XCliOptions.InputAsJsonArray {
		opts.Write.XCliOptions.InputStdin = convertJSONInput(inputData[0])
		return
	}

	// Treat input as new object on each line
	opts.Write.XCliOptions.InputStdin = inputData
}

// convertJSONInput converts a JSON array to a slice of strings for the writer to consume
func convertJSONInput(value string) []string {
	inputData := make([]string, 0)

	jsonArray := gjson.Parse(value)
	if !jsonArray.IsArray() {
		logrus.Fatal("--json-array option was passed, but input data is not a valid JSON array")
	}

	jsonArray.ForEach(func(key, value gjson.Result) bool {
		inputData = append(inputData, value.Raw)
		return true
	})

	return inputData
}