Revert "Use manual approach on entrypoint for now"

This reverts commit 929722d640.

entrypoint.sh

@@ -2,16 +2,30 @@
 
 set -e
 
-# Note(decentral1se): get file_env function back soon
-# https://git.autonomic.zone/coop-cloud/peertube/issues/2
+file_env() {
+   local var="$1"
+   local fileVar="${var}_FILE"
+   local def="${2:-}"
 
-export PEERTUBE_DB_PASSWORD=$(cat "$PEERTUBE_DB_PASSWORD_FILE")
-unset PEERTUBE_DB_PASSWORD_FILE
+   if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
+      echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
+      exit 1
+   fi
 
-if [ -z "$PEERTUBE_SMTP_ENABLED" ]; then
-export PEERTUBE_SMTP_PASSWORD=$(cat "$PEERTUBE_SMTP_PASSWORD_FILE")
-unset PEERTUBE_SMTP_PASSWORD_FILE
-fi
+   local val="$def"
+
+   if [ "${!var:-}" ]; then
+      val="${!var}"
+   elif [ "${!fileVar:-}" ]; then
+      val="$(< "${!fileVar}")"
+   fi
+
+   export "$var"="$val"
+   unset "$fileVar"
+}
+
+file_env "PEERTUBE_DB_PASSWORD"
+file_env "PEERTUBE_SMTP_PASSWORD"
 
 # upstream entrypoint
 # https://github.com/Chocobozzz/PeerTube/blob/66f77f63437c6774acbd72584a9839a7636ea167/support/docker/production/entrypoint.sh