NEW: convertzone/ Read BIND zone files, output records as DSL, TSV, o… (#49)

* NEW: convertzone/ Read BIND zone files, output records as DSL, TSV, or pretty-print.

* Refactored to be more gostyle.

* Fix buffering issue.

* Delete the hacky awk script.

* Linting.

misc/convertzone/README.md

@@ -0,0 +1,27 @@
+# convertzone -- Converts a standard DNS zonefile into tsv, pretty, or DSL
+
+convertzone converts an old-style DNS zone file into one of three formats:
+
+* -mode=pretty   Output the zone pretty-printed.
+* -mode=tsv      Output the zone recoreds as tab-separated values
+* -mode=dsl      Output the zone records as the DNSControl DSL language.
+
+
+NOTE: mode=dsl is not perfect. The result is something you'll want
+to fine-tune.  However it is better than manually converting big
+zones.
+
+You must give the script both the zone name (i.e. "stackoverflow.com")
+and the filename of the zonefile to read.
+
+Output is sent to stdout.
+
+Example:
+
+"""
+./convertzone stackoverflow.com zone.stackoverflow.com >new/stackoverflow.com
+"""
+
+Caveats:
+
+* `$INCLUDE` may not be handled correctly if you are not in the right directory.

misc/convertzone/main.go

@@ -0,0 +1,156 @@
+package main
+
+/*
+convertzone: Read BIND-style zonefile and output.
+
+     convertzone [-mode=MODE] zonename [filename]
+
+     -mode=tsv   TAB-separated values (default)
+     -mode=dsl   DNSControl DSL
+     -mode=pretty   Sort and pretty-print records.
+
+     zonename    The FQDN of the zone name.
+     filename    File to read (default: stdin)
+*/
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/StackExchange/dnscontrol/providers/bind"
+	"github.com/miekg/dns"
+	"github.com/miekg/dns/dnsutil"
+	"github.com/pkg/errors"
+)
+
+var flagMode = flag.String("mode", "tsv", "tsv|dsl|pretty")
+var flagDefaultTTL = flag.Uint("ttl", 300, "Default TTL")
+var flagRegText = flag.String("registrar", "REG_FILL_IN", "registrar text")
+var flagProviderText = flag.String("provider", "DNS_FILL_IN", "provider text")
+
+// parseargs parses the non-flag arguments.
+func parseargs(args []string) (zonename string, filename string, r io.Reader, err error) {
+	// 1 args: first arg is the zonename. Read stdin.
+	// 2 args: first arg is the zonename. 2nd is the filename.
+	// Anything else returns an error.
+
+	if len(args) < 1 {
+		return "", "", nil, fmt.Errorf("no command line parameters. Zone name required")
+	}
+
+	zonename = args[0]
+
+	if len(args) == 1 {
+		filename = "stdin"
+		r = bufio.NewReader(os.Stdin)
+	} else if len(args) == 2 {
+		filename = flag.Arg(1)
+		r, err = os.Open(filename)
+		if err != nil {
+			return "", "", nil, errors.Wrapf(err, "Could not open file: %s", filename)
+		}
+	} else {
+		return "", "", nil, fmt.Errorf("too many command line parameters")
+	}
+
+	return zonename, filename, r, nil
+}
+
+// pretty outputs the zonefile using the prettyprinter.
+func pretty(zonename string, filename string, r io.Reader, defaultTTL uint32) {
+	var l []dns.RR
+	for x := range dns.ParseZone(r, zonename, filename) {
+		if x.Error == nil {
+			l = append(l, x.RR)
+		}
+	}
+	bind.WriteZoneFile(os.Stdout, l, zonename, defaultTTL)
+}
+
+// rrFormat outputs the zonefile in either DSL or TSV format.
+func rrFormat(zonename string, filename string, r io.Reader, defaultTTL uint32, dsl bool) {
+	zonenamedot := zonename + "."
+
+	for x := range dns.ParseZone(r, zonename, filename) {
+		if x.Error != nil {
+			continue
+		}
+
+		// Skip comments. Parse the formatted version.
+		line := x.String()
+		if line[0] == ';' {
+			continue
+		}
+		items := strings.SplitN(line, "\t", 5)
+		if len(items) < 5 {
+			log.Fatalf("Too few items in: %v", line)
+		}
+
+		target := items[4]
+
+		hdr := x.Header()
+		nameFqdn := hdr.Name
+		name := dnsutil.TrimDomainName(nameFqdn, zonenamedot)
+		ttl := strconv.FormatUint(uint64(hdr.Ttl), 10)
+		classStr := dns.ClassToString[hdr.Class]
+		typeStr := dns.TypeToString[hdr.Rrtype]
+
+		// MX records should split out the prio vs. target.
+		if hdr.Rrtype == dns.TypeMX {
+			target = strings.Replace(target, " ", "\t", 1)
+		}
+
+		if !dsl { // TSV format:
+			fmt.Printf("%s\t%s\t%s\t%s\t%s\n", name, ttl, classStr, typeStr, target)
+		} else { // DSL format:
+			switch hdr.Rrtype {
+			case dns.TypeMX:
+				m := strings.SplitN(target, "\t", 2)
+				target = m[0] + ", '" + m[1] + "'"
+			case dns.TypeSOA:
+				continue
+			case dns.TypeTXT:
+				// Leave target as-is.
+			default:
+				target = "'" + target + "'"
+			}
+			if hdr.Ttl == defaultTTL {
+				ttl = ""
+			} else {
+				ttl = fmt.Sprintf(", TTL(%d)", hdr.Ttl)
+			}
+			fmt.Printf(",\n\t%s('%s', %s%s)", typeStr, name, target, ttl)
+		}
+	}
+
+}
+
+func main() {
+	flag.Parse()
+	zonename, filename, reader, err := parseargs(flag.Args())
+	if err != nil {
+		flag.Usage()
+	}
+
+	defTTL := uint32(*flagDefaultTTL)
+
+	switch *flagMode {
+	case "pretty":
+		pretty(zonename, filename, reader, defTTL)
+	case "dsl":
+		fmt.Printf(`D("%s", %s, DnsProvider(%s)`, zonename, *flagRegText, *flagProviderText)
+		rrFormat(zonename, filename, reader, defTTL, true)
+		fmt.Println("\n)")
+	case "tsv":
+		rrFormat(zonename, filename, reader, defTTL, false)
+	default:
+		flag.Usage()
+	}
+
+}