docker: make development database local folder and add wait for mysql logic

.dockerignore

@@ -113,3 +113,6 @@ config
 
 # celerybeat schedule database
 jdav_web/celerybeat-schedule.db
+
+# docker development database folder
+docker/development/db

.gitignore

@@ -114,3 +114,6 @@ jdav_web/celerybeat-schedule.db
 
 # docker environment variables
 docker.env
+
+# docker development database folder
+docker/development/db

docker/development/docker-compose.yaml

@@ -17,8 +17,8 @@ services:
     master:
         <<: *kompass
         entrypoint: /app/docker/development/entrypoint-master.sh
-        stdin_open: true # docker run -i
-        tty: true # docker run -t
+        stdin_open: true
+        tty: true
         volumes:
           - ./../../jdav_web:/app/jdav_web
         ports:
@@ -36,5 +36,5 @@ services:
         restart: always
         image: mariadb
         volumes:
-          - /tmp/db:/var/lib/mysql
+          - ./db:/var/lib/mysql
         env_file: docker.env

docker/development/entrypoint-master.sh

@@ -2,7 +2,31 @@
 
 set -o errexit
 
-sleep 5
+mysql_ready() {
+cd /app/jdav_web
+python << END
+import sys
+
+from django.db import connections
+from django.db.utils import OperationalError
+
+db_conn = connections['default']
+
+try:
+    c = db_conn.cursor()
+except OperationalError:
+    sys.exit(-1)
+else:
+    sys.exit(0)
+
+END
+}
+
+until mysql_ready; do
+    >&2 echo 'Waiting for MySQL to become available...'
+    sleep 1
+done
+>&2 echo 'MySQL is available'
 
 cd /app