override NATS URL with an environment variable (#2)

* override NATS URL with an environment variable

* go fmt

Author: zluudg

README.md

@@ -19,9 +19,6 @@ observation-encoder -config /path/to/config/file
 # Sample config file
 
 ```toml
-address = "127.0.0.1"
-port = "10000"
-
 [cert]
 interval = 100
 cert_dir = "/path/to/certs/dir"

cmd/observation-encoder/main.go

@@ -21,6 +21,8 @@ import (
 	"github.com/dnstapir/observation-encoder/internal/nats"
 )
 
+const c_ENVVAR_OVERRIDE_NATS_URL = "DNSTAPIR_NATS_URL"
+
 var commit = "BAD-BUILD"
 
 type conf struct {
@@ -105,6 +107,12 @@ func main() {
 		log.Error("Error creating nats log: %s", err)
 	}
 
+	envNatsUrl, overrideNatsUrl := os.LookupEnv(c_ENVVAR_OVERRIDE_NATS_URL)
+	if overrideNatsUrl {
+		mainConf.Nats.Url = envNatsUrl
+		log.Info("Overriding NATS url with environment variable '%s'", c_ENVVAR_OVERRIDE_NATS_URL)
+	}
+
 	mainConf.Nats.Log = natslog
 	natsHandle, err := nats.Create(mainConf.Nats)
 	if err != nil {

internal/app/app.go

@@ -14,9 +14,7 @@ const c_NATS_DELIM = common.NATS_DELIM
 
 type Conf struct {
 	Log            common.Logger
-	Debug          bool   `toml:"debug"`
-	Address        string `toml:"address"`
-	Port           string `toml:"port"`
+	Debug          bool `toml:"debug"`
 	NatsHandle     nats
 	LibtapirHandle libtapir
 }
@@ -26,8 +24,6 @@ type appHandle struct {
 	log            common.Logger
 	natsHandle     nats
 	libtapirHandle libtapir
-	address        string
-	port           string
 	exitCh         chan<- common.Exit
 	pm
 }
@@ -67,17 +63,7 @@ func Create(conf Conf) (*appHandle, error) {
 		return nil, common.ErrBadHandle
 	}
 
-	if conf.Address == "" {
-		return nil, common.ErrBadParam
-	}
-
-	if conf.Port == "" {
-		return nil, common.ErrBadParam
-	}
-
 	a.log = conf.Log
-	a.address = conf.Address
-	a.port = conf.Port
 	a.id = "main app"
 	a.natsHandle = conf.NatsHandle
 	a.libtapirHandle = conf.LibtapirHandle