Refactor to use better cli command framework (#177)

* starting to refactor commands

* work

* not sure

* all commands working!

* actually add file

* work in delay flag again

* start to refactor out console printing

* i hate line endings

* simple travis test to find direct output

* remove all direct printing from push/preview

* checkin vendor

* don't need this yet

* forgot to commit these

* make version explicit command

* some code review

* Add "check" subcommand.

* move stuff to commands package

* fix

* comment out check for printlns. for now

* alphabet hax

* activedir flags gone. use creds instead

* active dir doc update

* remove bind specific flags. creds instead

* default to zones dir

* fix linux build

* fix test

* cleanup random global* vars

* Clean up PowerShell docs

* rename dump-ir to print-ir. combine with print-js

commands/printIR.go

@@ -0,0 +1,132 @@
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/StackExchange/dnscontrol/models"
+	"github.com/StackExchange/dnscontrol/pkg/js"
+	"github.com/StackExchange/dnscontrol/pkg/normalize"
+	"github.com/urfave/cli"
+)
+
+var _ = cmd(catDebug, func() *cli.Command {
+	var args PrintIRArgs
+	return &cli.Command{
+		Name:  "print-ir",
+		Usage: "Output intermediate representation (IR) after running validation and normalization logic.",
+		Action: func(c *cli.Context) error {
+			return exit(PrintIR(args))
+		},
+		Flags: args.flags(),
+	}
+}())
+
+var _ = cmd(catDebug, func() *cli.Command {
+	var args PrintIRArgs
+	// This is the same as print-ir but output defaults to /dev/null.
+	return &cli.Command{
+		Name:  "check",
+		Usage: "Check and validate dnsconfig.js. Do not access providers.",
+		Action: func(c *cli.Context) error {
+			if args.Output == "" {
+				args.Output = os.DevNull
+			}
+			return exit(PrintIR(args))
+		},
+		Flags: args.flags(),
+	}
+}())
+
+type PrintIRArgs struct {
+	GetDNSConfigArgs
+	PrintJSONArgs
+	Raw bool
+}
+
+func (args *PrintIRArgs) flags() []cli.Flag {
+	flags := append(args.GetDNSConfigArgs.flags(), args.PrintJSONArgs.flags()...)
+	flags = append(flags, &cli.BoolFlag{
+		Name:        "raw",
+		Usage:       "Skip validation and normalization. Just print js result.",
+		Destination: &args.Raw,
+	})
+	return flags
+}
+
+func PrintIR(args PrintIRArgs) error {
+	cfg, err := GetDNSConfig(args.GetDNSConfigArgs)
+	if err != nil {
+		return err
+	}
+	if !args.Raw {
+		errs := normalize.NormalizeAndValidateConfig(cfg)
+		if PrintValidationErrors(errs) {
+			return fmt.Errorf("Exiting due to validation errors")
+		}
+	}
+	return PrintJSON(args.PrintJSONArgs, cfg)
+}
+
+func PrintValidationErrors(errs []error) (fatal bool) {
+	if len(errs) == 0 {
+		return false
+	}
+	fmt.Printf("%d Validation errors:\n", len(errs))
+	for _, err := range errs {
+		if _, ok := err.(normalize.Warning); ok {
+			fmt.Printf("WARNING: %s\n", err)
+		} else {
+			fatal = true
+			fmt.Printf("ERROR: %s\n", err)
+		}
+	}
+	return
+}
+
+func ExecuteDSL(args ExecuteDSLArgs) (*models.DNSConfig, error) {
+	if args.JSFile == "" {
+		return nil, fmt.Errorf("No config specified")
+	}
+	text, err := ioutil.ReadFile(args.JSFile)
+	if err != nil {
+		return nil, fmt.Errorf("Reading js file %s: %s", args.JSFile, err)
+	}
+	dnsConfig, err := js.ExecuteJavascript(string(text), args.DevMode)
+	if err != nil {
+		return nil, fmt.Errorf("Executing javascript in %s: %s", args.JSFile, err)
+	}
+	return dnsConfig, nil
+}
+
+func PrintJSON(args PrintJSONArgs, config *models.DNSConfig) (err error) {
+	var dat []byte
+	if args.Pretty {
+		dat, err = json.MarshalIndent(config, "", "  ")
+	} else {
+		dat, err = json.Marshal(config)
+	}
+	if err != nil {
+		return err
+	}
+	if args.Output != "" {
+		f, err := os.Create(args.Output)
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+		_, err = f.Write(dat)
+		return err
+	}
+	fmt.Println(string(dat))
+	return nil
+}
+
+func exit(err error) error {
+	if err == nil {
+		return nil
+	}
+	return cli.NewExitError(err, 1)
+}