From 2f6c41bf3517fb7817fa158833bdb1f58c7dd69d Mon Sep 17 00:00:00 2001
From: Lucas Beier <lucas.beier@gmail.com>
Date: Tue, 8 Aug 2017 14:44:26 -0300
Subject: [PATCH] Uses environment variables as fallback when no config file is
 used.

In our project we rather set the user and password as environment
variables instead of using them hardcoded in a file (following the 12
factor app recommendations). This commit is a propostal to use the
environment variables as fallback when no config file is used.
---
 README.md                                     |  5 ++---
 config/{icinga2.json => icinga2.json.example} |  0
 lib/icinga2.rb                                | 14 +++++++++-----
 3 files changed, 11 insertions(+), 8 deletions(-)
 rename config/{icinga2.json => icinga2.json.example} (100%)

diff --git a/README.md b/README.md
index f3aa853..d86fee4 100644
--- a/README.md
+++ b/README.md
@@ -160,7 +160,7 @@ In case you want to use client certificates, set the `client_cn` accordingly.
 
 ### Dashing Configuration
 
-Edit `config/icinga2.json` and adjust the settings for the Icinga 2 API credentials.
+Move `config/icinga2.json.example` to `config/icinga2.json` and adjust the settings for the Icinga 2 API credentials.
 
 ```
 vim config/icinga2.json
@@ -177,8 +177,7 @@ vim config/icinga2.json
 }
 ```
 
-If you don't have any configuration file yet, the default values from the example above
-will be used.
+If you don't have any configuration file, the environment variables `ICINGA_API_HOST`, `ICINGA_API_PORT`, `ICINGA_API_USER` and `ICINGA_API_PASSWORD` will be used. If these environment variables are not setted, an `ArgumentError` will raise.
 
 If you prefer to use client certificates, set `pki_path` accordingly. The Icinga 2
 job expects the certificate file names based on the local FQDN e.g. `pki/icinga2-master1.localdomain.crt`.
diff --git a/config/icinga2.json b/config/icinga2.json.example
similarity index 100%
rename from config/icinga2.json
rename to config/icinga2.json.example
diff --git a/lib/icinga2.rb b/lib/icinga2.rb
index ec3b65c..9fef205 100644
--- a/lib/icinga2.rb
+++ b/lib/icinga2.rb
@@ -93,12 +93,16 @@ def initialize(configFile)
         @password = @config["icinga2"]["api"]["password"]
         @pkiPath = @config["icinga2"]["api"]["pki_path"]
       else
-        @log.warn(sprintf('Config file %s not found! Using default config.', configFile))
-        @host = "localhost"
-        @port = 5665
-        @user = "dashing"
-        @password = "icinga2ondashingr0xx"
+        @log.warn(sprintf('Config file %s not found. Using ENV vars.', configFile))
+        @host = ENV['ICINGA_API_HOST']
+        @port = ENV['ICINGA_API_PORT']
+        @user = ENV['ICINGA_API_USER']
+        @password = ENV['ICINGA_API_PASSWORD']
         @pkiPath = "pki/"
+
+        if [@host, @port, @user, @password].all? {|value| value.nil? or value == ""}
+          raise ArgumentError.new('No config file or env var found!')
+        end
       end
 
       @apiVersion = "v1" # TODO: allow user to configure version?