From a8cf783874202d7ae9188c5308f2f58d5586b0b2 Mon Sep 17 00:00:00 2001
From: Meir Gabay <meir@prodops.io>
Date: Thu, 30 Jul 2020 18:12:43 +0300
Subject: [PATCH] eval env vars

---
 plugin.go | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/plugin.go b/plugin.go
index 511632f..331a6a1 100644
--- a/plugin.go
+++ b/plugin.go
@@ -372,9 +372,35 @@ func getTfoutPath() string {
 	return fmt.Sprintf("%s.plan.tfout", terraformDataDir)
 }
 
+func getStrBetween(value string, a string, b string) string {
+	// Get substring between two strings.
+	posFirst := strings.Index(value, a)
+	if posFirst == -1 {
+		return ""
+	}
+	posLast := strings.Index(value, b)
+	if posLast == -1 {
+		return ""
+	}
+	posFirstAdjusted := posFirst + len(a)
+	if posFirstAdjusted >= posLast {
+		return ""
+	}
+	return value[posFirstAdjusted:posLast]
+}
+
 func vars(vs map[string]string) []string {
 	var args []string
 	for k, v := range vs {
+		isEnvVar, err := regexp.Match(`^\${.*}$`, []byte(v))
+		if err != nil {
+			fmt.Println(err)
+		}
+		if isEnvVar {
+			envVarName := getStrBetween(v, "${", "}")
+			v = os.Getenv(envVarName)
+			fmt.Println(v)
+		}
 		args = append(args, "-var", fmt.Sprintf("%s=%s", k, v))
 	}
 	return args