Merge pull request #14 from open-dynaMIX/env_vars_in_templates

Access environment variables inside templates

README.md

@@ -386,6 +386,40 @@ Note that dotdrop uses different delimiters than
 * comment start = `{#@@`
 * comment end = `@@#}`
 
+## Available variables
+### Profile
+
+`{{@@ profile @@}}` contains the profile provided to dotdrop. Below example shows how it is used.
+
+### Environment variables
+
+It's possible to access environment variables inside the templates. This feature can be used like this:
+
+```
+{{@@ env['MY_VAR'] @@}}
+```
+
+This allows for storing host-specific properties and/or secrets in environment.
+
+You can have an `.env` file in the directory where your `config.yaml` lies:
+
+```
+# My variables for this host
+var1="some value"
+var2="some other value"
+
+# Some secrets
+pass="verysecurepassword"
+```
+Of course, this file should not be tracked by git (put it in your `.gitignore`).
+
+
+Then you can invoke dotdrop with the help of an alias like that:
+```
+alias dotdrop='eval $(grep -v "^#" ~/dotfiles/.env) ~/dotfiles/dotdrop.sh'
+```
+This loads all the variables from `.env` (while omitting lines starting with `#`) before calling `~/dotfiles/dotdrop.sh`.
+
 # Example
 
 Let's consider two hosts:

dotdrop/templategen.py

@@ -6,7 +6,7 @@ jinja2 template generator
 
 import os
 import utils
-from jinja2 import Environment, Template, FileSystemLoader
+from jinja2 import Environment, FileSystemLoader
 
 BLOCK_START = '{%@@'
 BLOCK_END = '@@%}'
@@ -48,12 +48,12 @@ class Templategen:
         length = len(self.base) + 1
         try:
             template = self.env.get_template(src[length:])
-            content = template.render(profile=profile)
+            content = template.render(profile=profile, env=os.environ)
         except UnicodeDecodeError:
             data = self._read_bad_encoded_text(src)
             template = self.env.from_string(data)
+            content = template.render(profile=profile, env=os.environ)
 
-        content = template.render(profile=profile)
         content = content.encode('UTF-8')
         return content