used flag for command line arguments

Former-commit-id: 2ac565e4d78c22ffafc25532ef0771d4c8fa6da6 [formerly 2b65957a84d49a578c09e005d4100b269b6dc8e5] [formerly 115c739d59b0f5ff34de0f51588e973e94e77689 [formerly f0fbd2c30f]]
Former-commit-id: f28ba24ecfad414f37d054b6099aeb8480776914 [formerly d4e575940c207425c74141f5a78c43f5323d437c]
Former-commit-id: bc1dc9204608c1a4cca74639c46a6edbad8d37c6

db.go

@@ -4,8 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
-	"path"
-	"runtime"
 	"time"
 
 	"github.com/boltdb/bolt"
@@ -15,12 +13,10 @@ var db *bolt.DB
 var open bool
 
 // Open to create the database and open
-func Open() error {
+func Open(filename string) error {
 	var err error
-	_, filename, _, _ := runtime.Caller(0) // get full path of this file
-	dbfile := path.Join(path.Dir(filename), "data.db")
 	config := &bolt.Options{Timeout: 30 * time.Second}
-	db, err = bolt.Open(dbfile, 0600, config)
+	db, err = bolt.Open(filename, 0600, config)
 	if err != nil {
 		fmt.Println("Opening BoltDB timed out")
 		log.Fatal(err)

main.go

@@ -1,26 +1,56 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
-	"os"
+	"path"
+	"runtime"
 
 	"github.com/gin-gonic/gin"
 )
 
-var ExternalIP string
-var AllowedIPs string
+// AllowedIPs is a white/black list of
+// IP addresses allowed to access cowyo
+var AllowedIPs = map[string]bool{
+	"192.168.1.13": true,
+	"192.168.1.12": true,
+	"192.168.1.2":  true,
+}
 
-func init() {
-	AllowedIPs = "192.168.1.13,192.168.1.12,192.168.1.2"
+// RuntimeArgs contains all runtime
+// arguments available
+var RuntimeArgs struct {
+	ExternalIP       string
+	Port             string
+	DatabaseLocation string
+	ServerCRT        string
+	ServerKey        string
 }
 
 func main() {
-	if len(os.Args) == 1 {
+	_, executableFile, _, _ := runtime.Caller(0) // get full path of this file
+	databaseFile := path.Join(path.Dir(executableFile), "data.db")
+	flag.StringVar(&RuntimeArgs.Port, "p", ":12312", "port to bind")
+	flag.StringVar(&RuntimeArgs.DatabaseLocation, "db", databaseFile, "location of database file")
+	flag.StringVar(&RuntimeArgs.ServerCRT, "crt", "", "location of ssl crt")
+	flag.StringVar(&RuntimeArgs.ServerKey, "key", "", "location of ssl key")
+	flag.CommandLine.Usage = func() {
+		fmt.Println(`cowyo: a websocket notepad
+run this to start the server and then visit localhost at the port you specify
+(see parameters).
+Example: 'cowyo localhost'
+Example: 'cowyo -p :8080 localhost'
+Example: 'cowyo -db /var/lib/cowyo/db.bolt localhost'
+Options:`)
+		flag.CommandLine.PrintDefaults()
+	}
+	flag.Parse()
+	RuntimeArgs.ExternalIP = flag.Arg(0)
+	if RuntimeArgs.ExternalIP == "" {
 		log.Fatal("You need to specify the external IP address")
 	}
-	ExternalIP = os.Args[1]
-	Open()
+	Open(RuntimeArgs.DatabaseLocation)
 	defer Close()
 
 	// Default page
@@ -34,5 +64,5 @@ func main() {
 	r.GET("/:title", editNote)
 	r.GET("/:title/*option", everythingElse)
 	r.DELETE("/listitem", deleteListItem)
-	r.Run(":12312")
+	r.Run(RuntimeArgs.Port)
 }

routes.go

@@ -26,7 +26,7 @@ func editNote(c *gin.Context) {
 	} else {
 		c.HTML(http.StatusOK, "index.tmpl", gin.H{
 			"Title":      title,
-			"ExternalIP": ExternalIP,
+			"ExternalIP": RuntimeArgs.ExternalIP,
 		})
 	}
 }