Use CLI flags in addition to env vars for config

cmd/twigs/main.go

@@ -8,28 +8,79 @@ import (
 	"os"
 
 	"github.com/gorilla/mux"
-	_ "github.com/go-sql-driver/mysql"
+	_ "github.com/lib/pq"
+	"github.com/urfave/cli/v2"
 )
 
-func getEnvOrDefault(env string, defaultVal string) string {
-	envVal := os.Getenv(env)
-	if envVal == "" {
-		return defaultVal
-	} else {
-		return envVal
-	}
-}
+const ARG_PORT = "port"
+const ARG_DB_NAME = "db-name"
+const ARG_DB_USER = "db-user"
+const ARG_DB_PASS = "db-pass"
+const ARG_DB_HOST = "db-host"
+const ARG_DB_PORT = "db-port"
 
 func main() {
-	dbName := getEnvOrDefault("TWIGS_DB_NAME", "budget")
-	dbUser := getEnvOrDefault("TWIGS_DB_USER", "budget")
-	dbPass := getEnvOrDefault("TWIGS_DB_PASS", "budget")
-	dbHost := getEnvOrDefault("TWIGS_DB_HOST", "localhost")
-	dbPort := getEnvOrDefault("TWIGS_DB_PORT", "3306")
-	db, err := sql.Open("mysql", fmt.Sprintf("%s:%s@%s:%s/%s", dbUser, dbPass, dbHost, dbPort, dbName))
-	if err != nil {
-		log.Fatalf("Failed to connect to database %s on %s", dbName, dbHost)
+	app := &cli.App{
+		Name:  "twigs",
+		Usage: "personal/family finance app server",
+		Flags: []cli.Flag{
+			&cli.IntFlag{
+				Name:    ARG_PORT,
+				Value:   8080,
+				Usage:   "the `PORT` for the server to listen on",
+				Aliases: []string{"p"},
+				EnvVars: []string{"TWIGS_PORT"},
+			},
+			&cli.StringFlag{
+				Name:    ARG_DB_NAME,
+				Value:   "twigs",
+				Usage:   "the `NAME` of the database to connect to",
+				EnvVars: []string{"TWIGS_DB_NAME"},
+			},
+			&cli.StringFlag{
+				Name:    ARG_DB_USER,
+				Value:   "twigs",
+				Usage:   "the `USERNAME` to use to connect to the database",
+				EnvVars: []string{"TWIGS_DB_USER"},
+			},
+			&cli.StringFlag{
+				Name:    ARG_DB_PASS,
+				Value:   "twigs",
+				Usage:   "the `PASSWORD` to use to connect to the database",
+				EnvVars: []string{"TWIGS_DB_PASS"},
+			},
+			&cli.StringFlag{
+				Name:    ARG_DB_HOST,
+				Value:   "twigs",
+				Usage:   "the `HOST` to use to connect to the database",
+				EnvVars: []string{"TWIGS_DB_HOST"},
+			},
+			&cli.IntFlag{
+				Name:    ARG_DB_PORT,
+				Value:   5432,
+				Usage:   "the `PORT` to use to connect to the database",
+				EnvVars: []string{"TWIGS_DB_PORT"},
+			},
+		},
+		Action: func(c *cli.Context) error {
+			_, err := sql.Open("postgres", fmt.Sprintf(
+				"%s:%s@%s:%d/%s",
+				c.String(ARG_DB_USER),
+				c.String(ARG_DB_PASS),
+				c.String(ARG_DB_HOST),
+				c.Int(ARG_DB_PORT),
+				c.String(ARG_DB_NAME),
+			))
+			if err != nil {
+				log.Fatalf("Failed to connect to database %s on %s", c.String(ARG_DB_NAME), c.String(ARG_DB_HOST))
+			}
+			_ = mux.NewRouter()
+			log.Fatal(http.ListenAndServe(":8080", nil))
+			return nil
+		},
+	}
+	err := app.Run(os.Args)
+	if err != nil {
+		log.Fatal(err)
 	}
-	router := mux.NewRouter()
-	log.Fatal(http.ListenAndServe(":8080", nil))
 }

go.mod

@@ -1,3 +1,9 @@
 module wbrawner.com/twigs
 
 go 1.16
+
+require (
+	github.com/gorilla/mux v1.8.0
+	github.com/lib/pq v1.10.6
+	github.com/urfave/cli/v2 v2.8.0
+)

go.sum

@@ -0,0 +1,17 @@
+github.com/BurntSushi/toml v1.1.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
+github.com/antzucaro/matchr v0.0.0-20210222213004-b04723ef80f0 h1:R/qAiUxFT3mNgQaNqJe0IVznjKRNm23ohAIh9lgtlzc=
+github.com/antzucaro/matchr v0.0.0-20210222213004-b04723ef80f0/go.mod h1:v3ZDlfVAL1OrkKHbGSFFK60k0/7hruHPDq2XMs9Gu6U=
+github.com/cpuguy83/go-md2man/v2 v2.0.1 h1:r/myEWzV9lfsM1tFLgDyu0atFtJ1fXn261LKYj/3DxU=
+github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/lib/pq v1.10.6 h1:jbk+ZieJ0D7EVGJYpL9QTz7/YW6UHbmdnZWYyK5cdBs=
+github.com/lib/pq v1.10.6/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/urfave/cli/v2 v2.8.0 h1:EZsAB20oRW4nHcB99TTL6PrXpBGIEujMEKdjwruY9KQ=
+github.com/urfave/cli/v2 v2.8.0/go.mod h1:TYFbtzt/azQoJOrGH5mDfZtS0jIkl/OeFwlRWPR9KRM=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=