feat: support multi-lines environment variables substitution

README.md

@@ -292,7 +292,21 @@ In order to be able to implement some **genericity** in your scripts and templat
     * any [GitLab CI variable](https://docs.gitlab.com/ee/ci/variables/#predefined-environment-variables)
       (ex: `${CI_ENVIRONMENT_URL}` to retrieve the actual environment exposed route)
 
-> :warning: In order to be properly replaced, variables in your YAML descriptors shall be written with curly braces (ex: `${MYVAR}` and not `$MYVAR`).
+> :warning:
+>
+> In order to be properly replaced, variables in your YAML descriptors shall be written with curly braces (ex: `${MYVAR}` and not `$MYVAR`).
+>
+> Multiline variables must be surrounded by **double quotes** (`"`). Example:
+>
+> ```yaml
+> [...]
+> containers:
+> - name: restaurant-app
+>   env:
+>   # multiline variable
+>   - name: MENU
+>     value: "${APP_MENU}"
+> ```
 
 ## kube-score job
 

templates/gitlab-ci-k8s.yml

@@ -236,7 +236,7 @@ stages:
   }
 
   function awkenvsubst() {
-    awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);gsub("[$]{"var"}",ENVIRON[var])}}1'
+    awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);val=ENVIRON[var];gsub(/["\\]/,"\\\\&", val);gsub("\n", "\\n", val);gsub("\r", "\\r", val);gsub("[$]{"var"}",val)}}1'
   }
 
   function login() {