circolog/cmd/circologctl/main.go

package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"net"
	"net/http"
	"os"
	"time"

	"git.lattuga.net/boyska/circolog"
)

var globalOpts struct {
	ctlSock string
	verbose bool
	debug   bool
}

var ctl http.Client

type commandFunc func([]string) error

var cmdMap map[string]commandFunc

func init() {
	cmdMap = map[string]commandFunc{
		// TODO: implement set and get of config at runtime
		//"set":     setCmd,
		//"get":     getCmd,
		"status":  statusCmd,
		"pause":   pauseCmd,
		"reload":  reloadCmd,
		"restart": restartCmd,
		"help":    helpCmd,
	}
}

//func setCmd(ctlSock string, args []string) error {}

//func getCmd(ctlSock string, args []string) error {}

func statusCmd(args []string) error {
	flagset := flag.NewFlagSet(args[0], flag.ExitOnError)
	outFormat := flagset.String("format", "plain", "Which format to use as output for this command (json, pretty, plain)")
	flagset.Parse(args[1:])
	resp, err := ctl.Get("http://unix/status")
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	respBytes, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	respJSON := make(map[string]circolog.StatusResponse)
	err = json.Unmarshal(respBytes, &respJSON)
	if err != nil {
		return err
	}
	switch *outFormat {
	case "json":
		fmt.Printf("%s", string(respBytes))
	case "pretty":
		prettyJSON, err := json.MarshalIndent(respJSON, "", "  ")
		if err != nil {
			return err
		}
		fmt.Printf("%s\n", prettyJSON)
	case "plain":
		fmt.Printf("Buffer Length: %d\n", respJSON["status"].Len)
		fmt.Printf("Server Status: %s\n", respJSON["status"].Status())
	}
	return nil
}

func pauseCmd(args []string) error {
	var dontChangeAgain time.Duration
	flagset := flag.NewFlagSet(args[0], flag.ExitOnError)
	waitTime := flagset.Duration("wait-time", dontChangeAgain, "How long to wait before untoggling the state, defaults to never")
	flagset.Parse(args[1:])
	postBody := make(map[string][]string)
	if *waitTime != dontChangeAgain {
		postBody["waitTime"] = []string{fmt.Sprintf("%s", *waitTime)}
	}
	if globalOpts.debug {
		fmt.Println("[DEBUG] postBody:", postBody)
	}
	resp, err := ctl.PostForm("http://unix/pause/toggle", postBody)
	if globalOpts.verbose {
		defer resp.Body.Close()
		bodyBytes, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return err
		}
		fmt.Println(string(bodyBytes))
	}
	return err
}

func reloadCmd(args []string) error {
	return nil
}

func restartCmd(args []string) error {
	return nil
}

func helpCmd(args []string) error {
	usage(os.Stdout)
	os.Exit(0)
	return nil
}

func usage(w io.Writer) {
	fmt.Fprintf(w, "USAGE: %s [globalOpts] [SUBCOMMAND] [opts]\n", os.Args[0])
	fmt.Fprintf(w, "\nSUBCOMMANDS:\n\n")
	for command := range cmdMap {
		fmt.Fprintf(w, "\t%s\n", command)
	}
}

func parseAndRun(args []string) {
	cmdName := args[0]
	cmdToRun, ok := cmdMap[cmdName]
	if !ok {
		fmt.Fprintf(os.Stderr, "Unknown subcommand: %s\n", cmdName)
		usage(os.Stderr)
		os.Exit(2)
	}
	// from here: https://gist.github.com/teknoraver/5ffacb8757330715bcbcc90e6d46ac74
	ctl = http.Client{
		Transport: &http.Transport{
			DialContext: func(_ context.Context, _, _ string) (net.Conn, error) {
				return net.Dial("unix", globalOpts.ctlSock)
			},
		},
	}
	err := cmdToRun(args)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error:\n%s\n", err)
		os.Exit(1)
	}
}

func main() {
	flag.StringVar(&globalOpts.ctlSock, "ctl-socket", "/tmp/circologd-ctl.sock",
		"Path to a unix domain socket for the control server; leave empty to disable")
	flag.BoolVar(&globalOpts.verbose, "verbose", false, "Print more output")
	flag.BoolVar(&globalOpts.debug, "debug", false, "Print debugging info")
	flag.Parse()
	args := flag.Args()
	if len(args) == 0 {
		usage(os.Stderr)
		os.Exit(-1)
	}
	parseAndRun(args)
}