Panic if user is using -envfile flag

README.md

@@ -80,6 +80,16 @@ docker-compose down
 
 ## Configuration
 
+The application is configured using _environment variables_.
+
+If you have an existing `.env` file (or you were using `-envfile`) you can run a command with the variables loaded:
+
+    # Replace <command> with the command you want to run
+    env $(grep -e '^#' .env | xargs) <command>
+
+    # For example
+    env $(grep -e '^#' .env | xargs) go run main.go
+
 ### Maintenance mode
 
 You can put the service in maintenance mode via the [System API](https://flow-hydraulics.github.io/flow-wallet-api/#tag/System) by sending the following JSON body as a `POST` request to `/system/settings` (example in [api-test-scripts/system.http](api-test-scripts/system.http)):

go.mod

@@ -15,8 +15,6 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/gorilla/handlers v1.5.1
 	github.com/gorilla/mux v1.8.0
-	github.com/jackc/pgx/v4 v4.14.1 // indirect
-	github.com/joho/godotenv v1.4.0 // indirect
 	github.com/jpillora/backoff v1.0.0
 	github.com/lib/pq v1.10.4
 	github.com/onflow/cadence v0.20.1
@@ -72,6 +70,7 @@ require (
 	github.com/jackc/pgx/v4 v4.14.1 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.4 // indirect
+	github.com/joho/godotenv v1.4.0 // indirect
 	github.com/logrusorgru/aurora v2.0.3+incompatible // indirect
 	github.com/mattn/go-sqlite3 v1.14.10 // indirect
 	github.com/onflow/atree v0.1.0-beta1.0.20211027184039-559ee654ece9 // indirect

main.go

@@ -38,12 +38,20 @@ var (
 )
 
 func main() {
-	var printVersion bool
+	var (
+		printVersion bool
+		envFilePath  string // LEGACY: now used to check if user still is using envFilePath
+	)
+
 	// If we should just print the version number and exit
 	flag.BoolVar(&printVersion, "version", false, "if true, print version and exit")
-
+	flag.StringVar(&envFilePath, "envfile", "", "deprecated")
 	flag.Parse()
 
+	if envFilePath != "" {
+		panic("'-envfile' is no longer supported, see readme")
+	}
+
 	if printVersion {
 		fmt.Printf("v%s build on %s from sha1 %s\n", version, buildTime, sha1ver)
 		os.Exit(0)