Make CoreDNS a server type plugin for Caddy (#220)

* Make CoreDNS a server type plugin for Caddy

Remove code we don't need and port all middleware over. Fix all tests
and rework the documentation.

Also make `go generate` build a caddy binary which we then copy into
our directory. This means `go build`-builds remain working as-is.

And new etc instances in each etcd test for better isolation.
Fix more tests and rework test.Server with the newer support Caddy offers.

Fix Makefile to support new mode of operation.

1 files changed, 0 insertions, 232 deletions

diff --git a/core/coremain/run.go b/core/coremain/run.go
deleted file mode 100644
index 407beb1c6..000000000
--- a/core/coremain/run.go
+++ /dev/null
@@ -1,232 +0,0 @@
-package coremain
-
-import (
-	"errors"
-	"flag"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"os"
-	"runtime"
-	"strconv"
-	"strings"
-	"time"
-
-	"github.com/miekg/coredns/core"
-	"github.com/miekg/coredns/core/https"
-	"github.com/xenolf/lego/acme"
-	"gopkg.in/natefinch/lumberjack.v2"
-)
-
-func init() {
-	core.TrapSignals()
-	setVersion()
-	flag.BoolVar(&https.Agreed, "agree", false, "Agree to Let's Encrypt Subscriber Agreement")
-	flag.StringVar(&https.CAUrl, "ca", "https://acme-v01.api.letsencrypt.org/directory", "Certificate authority ACME server")
-	flag.StringVar(&conf, "conf", "", "Configuration file to use (default="+core.DefaultConfigFile+")")
-	flag.StringVar(&cpu, "cpu", "100%", "CPU cap")
-	flag.StringVar(&https.DefaultEmail, "email", "", "Default Let's Encrypt account email address")
-	flag.DurationVar(&core.GracefulTimeout, "grace", 5*time.Second, "Maximum duration of graceful shutdown")
-	flag.StringVar(&core.Host, "host", core.DefaultHost, "Default host")
-	flag.StringVar(&logfile, "log", "", "Process log file")
-	flag.StringVar(&core.PidFile, "pidfile", "", "Path to write pid file")
-	flag.StringVar(&core.Port, "port", core.DefaultPort, "Default port")
-	flag.BoolVar(&core.Quiet, "quiet", false, "Quiet mode (no initialization output)")
-	flag.StringVar(&revoke, "revoke", "", "Hostname for which to revoke the certificate")
-	flag.StringVar(&core.Root, "root", core.DefaultRoot, "Root path to default zone files")
-	flag.BoolVar(&version, "version", false, "Show version")
-}
-
-func Run() {
-	flag.Parse() // called here in Run() to allow other packages to set flags in their inits
-
-	core.AppName = appName
-	core.AppVersion = appVersion
-	acme.UserAgent = appName + "/" + appVersion
-
-	// set up process log before anything bad happens
-	switch logfile {
-	case "stdout":
-		log.SetOutput(os.Stdout)
-	case "stderr":
-		log.SetOutput(os.Stderr)
-	case "":
-		log.SetOutput(ioutil.Discard)
-	default:
-		log.SetOutput(&lumberjack.Logger{
-			Filename:   logfile,
-			MaxSize:    100,
-			MaxAge:     14,
-			MaxBackups: 10,
-		})
-	}
-
-	if revoke != "" {
-		err := https.Revoke(revoke)
-		if err != nil {
-			log.Fatal(err)
-		}
-		fmt.Printf("Revoked certificate for %s\n", revoke)
-		os.Exit(0)
-	}
-	if version {
-		fmt.Printf("%s %s\n", appName, appVersion)
-		if devBuild && gitShortStat != "" {
-			fmt.Printf("%s\n%s\n", gitShortStat, gitFilesModified)
-		}
-		os.Exit(0)
-	}
-
-	// Set CPU cap
-	err := setCPU(cpu)
-	if err != nil {
-		mustLogFatal(err)
-	}
-
-	// Get Corefile input
-	corefile, err := core.LoadCorefile(loadCorefile)
-	if err != nil {
-		mustLogFatal(err)
-	}
-
-	// Start your engines
-	err = core.Start(corefile)
-	if err != nil {
-		mustLogFatal(err)
-	}
-
-	// Twiddle your thumbs
-	core.Wait()
-}
-
-// mustLogFatal just wraps log.Fatal() in a way that ensures the
-// output is always printed to stderr so the user can see it
-// if the user is still there, even if the process log was not
-// enabled. If this process is a restart, however, and the user
-// might not be there anymore, this just logs to the process log
-// and exits.
-func mustLogFatal(args ...interface{}) {
-	if !core.IsRestart() {
-		log.SetOutput(os.Stderr)
-	}
-	log.Fatal(args...)
-}
-
-func loadCorefile() (core.Input, error) {
-	// Try -conf flag
-	if conf != "" {
-		if conf == "stdin" {
-			return core.CorefileFromPipe(os.Stdin)
-		}
-
-		contents, err := ioutil.ReadFile(conf)
-		if err != nil {
-			return nil, err
-		}
-
-		return core.CorefileInput{
-			Contents: contents,
-			Filepath: conf,
-			RealFile: true,
-		}, nil
-	}
-
-	// command line args
-	if flag.NArg() > 0 {
-		confBody := core.Host + ":" + core.Port + "\n" + strings.Join(flag.Args(), "\n")
-		return core.CorefileInput{
-			Contents: []byte(confBody),
-			Filepath: "args",
-		}, nil
-	}
-
-	// Corefile in cwd
-	contents, err := ioutil.ReadFile(core.DefaultConfigFile)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return core.DefaultInput(), nil
-		}
-		return nil, err
-	}
-	return core.CorefileInput{
-		Contents: contents,
-		Filepath: core.DefaultConfigFile,
-		RealFile: true,
-	}, nil
-}
-
-// setCPU parses string cpu and sets GOMAXPROCS
-// according to its value. It accepts either
-// a number (e.g. 3) or a percent (e.g. 50%).
-func setCPU(cpu string) error {
-	var numCPU int
-
-	availCPU := runtime.NumCPU()
-
-	if strings.HasSuffix(cpu, "%") {
-		// Percent
-		var percent float32
-		pctStr := cpu[:len(cpu)-1]
-		pctInt, err := strconv.Atoi(pctStr)
-		if err != nil || pctInt < 1 || pctInt > 100 {
-			return errors.New("invalid CPU value: percentage must be between 1-100")
-		}
-		percent = float32(pctInt) / 100
-		numCPU = int(float32(availCPU) * percent)
-	} else {
-		// Number
-		num, err := strconv.Atoi(cpu)
-		if err != nil || num < 1 {
-			return errors.New("invalid CPU value: provide a number or percent greater than 0")
-		}
-		numCPU = num
-	}
-
-	if numCPU > availCPU {
-		numCPU = availCPU
-	}
-
-	runtime.GOMAXPROCS(numCPU)
-	return nil
-}
-
-// setVersion figures out the version information based on
-// variables set by -ldflags.
-func setVersion() {
-	// A development build is one that's not at a tag or has uncommitted changes
-	devBuild = gitTag == "" || gitShortStat != ""
-
-	// Only set the appVersion if -ldflags was used
-	if gitNearestTag != "" || gitTag != "" {
-		if devBuild && gitNearestTag != "" {
-			appVersion = fmt.Sprintf("%s (+%s %s)",
-				strings.TrimPrefix(gitNearestTag, "v"), gitCommit, buildDate)
-		} else if gitTag != "" {
-			appVersion = strings.TrimPrefix(gitTag, "v")
-		}
-	}
-}
-
-const appName = "CoreDNS"
-
-// Flags that control program flow or startup
-var (
-	conf    string
-	cpu     string
-	logfile string
-	revoke  string
-	version bool
-)
-
-// Build information obtained with the help of -ldflags
-var (
-	appVersion = "(untracked dev build)" // inferred at startup
-	devBuild   = true                    // inferred at startup
-
-	buildDate        string // date -u
-	gitTag           string // git describe --exact-match HEAD 2> /dev/null
-	gitNearestTag    string // git describe --abbrev=0 --tags HEAD
-	gitCommit        string // git rev-parse HEAD
-	gitShortStat     string // git diff-index --shortstat
-	gitFilesModified string // git diff-index --name-only HEAD
-)