simplify variable usage

Author: matemoln

README.md

@@ -22,16 +22,16 @@ respective files and pass them to the `docker stack deploy` command.
 
 The stack name can be ommited, in that case the current directory name will be used instead.
 
-## Changes
+## Changes to codestation/docker-deploy
 
 - Paths to files are resolved correctly even when docker-deploy is called from an other directory. E.g.: `docker-deploy -c /home/user/deployment/app/app.yml app`
 
-- If there is a variable in the filename such as below, the resulting environment variable will be created based on the parent directory + extension of the file.
+- If there is a variable in the filename such as below, the resulting environment variable will be created based on the variable.
 
 ```yaml
 secrets:
   secrets.env:
-    name: ${APP_NAME}.env.${SECRETS_ENV}
+    name: ${APP_NAME}.env.${APP_NAME_ENV}
     file: ../secrets/${APP_NAME}.env
 ```
 

main.go

@@ -54,11 +54,8 @@ func fileHash(filePath string) (string, error) {
 func newFileEnvironment(filePath string, filename string) (string, error) {
 	variableName := filePath
 	if strings.Contains(filePath, "$") {
-		fileExt := path.Ext(filePath)
-		containingDir := path.Base(path.Dir(filePath))
-		variableName = containingDir + fileExt
-
 		variableInFilePath := strings.Split(strings.Split(filePath, "${")[1],"}")[0]
+		variableName = strings.Replace(filePath, "${" + variableInFilePath + "}", variableInFilePath, 1)
 		filePath = strings.Replace(filePath, "${" + variableInFilePath + "}", os.Getenv(variableInFilePath), 1)
 		// log.Printf("replaced " + variableInFilePath + " to " + os.Getenv(variableInFilePath))
 	}