From a198cb700e12ecb2d43ad3cc0bc3f655382c4b15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johnny=20Bergstr=C3=B6m?= <github@joonix.se>
Date: Thu, 2 Nov 2017 17:55:42 +0100
Subject: [PATCH] Add env & expandenv template functions

Using environment variables is a common practice when deploying
docker containers.
---
 template/template.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/template/template.go b/template/template.go
index cb54b8cb63..d1eb5fec43 100644
--- a/template/template.go
+++ b/template/template.go
@@ -16,6 +16,7 @@ package template
 import (
 	"bytes"
 	"net/url"
+	"os"
 	"path/filepath"
 	"regexp"
 	"sort"
@@ -135,6 +136,8 @@ var DefaultFuncs = FuncMap{
 		re := regexp.MustCompile(pattern)
 		return re.ReplaceAllString(text, repl)
 	},
+	"env":       func(s string) string { return os.Getenv(s) },
+	"expandenv": func(s string) string { return os.ExpandEnv(s) },
 }
 
 // Pair is a key/value string pair.