Add a -version flag to Houndd (hound-search#362)

This commit adds a `-version` flag to houndd. Running `houndd -version` prints the current version and exits.

Co-authored-by: Kartikay Shandil <kartikays@sahaj.ai>

cmds/houndd/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"flag"
+	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -13,6 +14,7 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/blang/semver"
 	"github.com/hound-search/hound/api"
 	"github.com/hound-search/hound/config"
 	"github.com/hound-search/hound/searcher"
@@ -113,6 +115,14 @@ func runHttp(
 	return http.ListenAndServe(addr, m)
 }
 
+func getVersion() semver.Version {
+	return semver.Version{
+		Major: 0,
+		Minor: 3,
+		Patch: 0,
+	}
+}
+
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
 	info_log = log.New(os.Stdout, "", log.LstdFlags)
@@ -121,9 +131,15 @@ func main() {
 	flagConf := flag.String("conf", "config.json", "")
 	flagAddr := flag.String("addr", ":6080", "")
 	flagDev := flag.Bool("dev", false, "")
+	flagVer := flag.Bool("version", false, "Display version and exit")
 
 	flag.Parse()
 
+	if *flagVer {
+		fmt.Printf("houndd v%s", getVersion())
+		os.Exit(0)
+	}
+
 	var cfg config.Config
 	if err := cfg.LoadFromFile(*flagConf); err != nil {
 		panic(err)

go.mod

@@ -2,4 +2,7 @@ module github.com/hound-search/hound
 
 go 1.13
 
-require github.com/go-bindata/go-bindata v3.1.2+incompatible // indirect
+require (
+	github.com/blang/semver v3.5.1+incompatible
+	github.com/go-bindata/go-bindata v3.1.2+incompatible // indirect
+)

go.sum

@@ -1,3 +1,6 @@
+github.com/blang/semver v1.1.0 h1:ol1rO7QQB5uy7umSNV7VAmLugfLRD+17sYJujRNYPhg=
+github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
+github.com/blang/semver v3.5.1+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
 github.com/go-bindata/go-bindata v1.0.0 h1:DZ34txDXWn1DyWa+vQf7V9ANc2ILTtrEjtlsdJRF26M=
 github.com/go-bindata/go-bindata v3.1.2+incompatible h1:5vjJMVhowQdPzjE1LdxyFF7YFTXg5IgGVW4gBr5IbvE=
 github.com/go-bindata/go-bindata v3.1.2+incompatible/go.mod h1:xK8Dsgwmeed+BBsSy2XTopBn/8uK2HWuGSnA11C3Joo=