From de6d4beef90dc4f5710d649172ebc316ac4f047d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mari=C3=A1n=20Skrip?= <marian@skrip.sk>
Date: Sat, 19 Feb 2022 01:56:02 +0100
Subject: [PATCH] feat(config): add option to specify default value to env var
 expansion (#5020)

* feat: Add option to specify default value to env var expansion

* fix: remove unused capturing group for env var replacement

Co-authored-by: Nicolas Giard <github@ngpixel.com>
---
 dev/build/config.yml     | 4 ++--
 server/helpers/config.js | 8 ++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/dev/build/config.yml b/dev/build/config.yml
index 6f1a61b4..d9e58761 100644
--- a/dev/build/config.yml
+++ b/dev/build/config.yml
@@ -15,6 +15,6 @@ ssl:
   provider: letsencrypt
   domain: $(LETSENCRYPT_DOMAIN)
   subscriberEmail: $(LETSENCRYPT_EMAIL)
-logLevel: info
-logFormat: $(LOG_FORMAT)
+logLevel: $(LOG_LEVEL:info)
+logFormat: $(LOG_FORMAT:default)
 ha: $(HA_ACTIVE)
diff --git a/server/helpers/config.js b/server/helpers/config.js
index 0e6ab563..6f972d40 100644
--- a/server/helpers/config.js
+++ b/server/helpers/config.js
@@ -8,14 +8,18 @@ module.exports = {
   /**
    * Parse configuration value for environment vars
    *
+   * Replaces `$(ENV_VAR_NAME)` with value of `ENV_VAR_NAME` environment variable.
+   *
+   * Also supports defaults by if provided as `$(ENV_VAR_NAME:default)`
+   *
    * @param {any} cfg Configuration value
    * @returns Parse configuration value
    */
   parseConfigValue (cfg) {
     return _.replace(
       cfg,
-      /\$\(([A-Z0-9_]+)\)/g,
-      (fm, m) => { return process.env[m] }
+      /\$\(([A-Z0-9_]+)(?::(.+))?\)/g,
+      (fm, m, d) => { return process.env[m] || d }
     )
   },