Wait script for docker compose

backend/Dockerfile

@@ -3,7 +3,7 @@ FROM python:3.8-slim-buster
 # Update packages and
 # prepare alembic for docker compose setup
 RUN apt-get update && \
-    apt-get install -y libpq-dev gcc && \
+    apt-get install -y libpq-dev gcc curl && \
     rm -rf /var/lib/apt/lists/* && \
     pip3 install --no-cache-dir --upgrade pip setuptools && \
     pip3 install --no-cache-dir psycopg2-binary alembic

backend/configs/docker_wait.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env sh
+
+set -e
+  
+HOST="$1"
+shift
+
+until curl --request GET --url "http://$HOST/ping"; do
+  >&2 echo "$HOST is unavailable, sleeping"
+  sleep 1
+done
+
+>&2 echo "$HOST is up"