Add docker secret support

Author: abelfodil

README.md

@@ -44,6 +44,8 @@ Default login is `wallabag:wallabag`.
 - `-e POPULATE_DATABASE=...`(defaults to "True". Does the DB has to be populated or is it an existing one)
 - `-e SYMFONY__ENV__SERVER_NAME=...` (defaults to "Your wallabag instance". Specifies a user-friendly name for the 2FA issuer)
 
+To set any of these environment variables from a file (for instance a Docker Secret), append `__FILE` to the name of the environment variable.
+
 ## SQLite
 
 The easiest way to start wallabag is to use the SQLite backend. You can spin that up with

root/entrypoint.sh

@@ -1,5 +1,14 @@
 #!/bin/sh
 
+FILE_ENV_VARS="$(env | grep '__FILE=')"
+for env_var in $FILE_ENV_VARS; do
+    var_name="$(echo $env_var | grep -o '.*__FILE=' | sed 's/__FILE=//g')"
+    file_path="$(echo $env_var | grep -o '__FILE=.*' | sed 's/__FILE=//g')"
+    file_content="$(cat $file_path)"
+    new_var="$(echo $var_name=$file_content)"
+    export $(echo $new_var | xargs)
+done
+
 provisioner () {
     echo "Starting provisioner..."
     if ! out=`ansible-playbook -i /etc/ansible/hosts /etc/ansible/entrypoint.yml -c local "$@"`;then