connect backend to db in nginx-flask-mysql

Signed-off-by: Anca Iordache <anca.iordache@docker.com>

nginx-flask-mysql/backend/hello.py

@@ -1,6 +1,41 @@
+import os
+import time
 from flask import Flask
+import mysql.connector
+
+passfile = open('/run/secrets/db-password', 'r')
+
+#give db some time to start
+time.sleep(3)
+#connect to db
+conn = mysql.connector.connect(
+    user='root', 
+    password=passfile.read(),
+    host='db', # name of the mysql service as set in the docker-compose file
+    database='example',
+    auth_plugin='mysql_native_password'
+)
+passfile.close()
+
+cursor = conn.cursor()
+
 app = Flask(__name__)
 
 @app.route('/')
-def hello_world():
-    return 'Hello world'
+def listBlog():
+    cursor.execute('SELECT title FROM blog')
+    response = ''
+    for c in cursor:
+        response = response  + '<div>' + c[0] + '</div>'
+    return response
+
+def prepare_db():
+    cursor.execute('DROP TABLE IF EXISTS blog')
+    cursor.execute('CREATE TABLE blog (id INT AUTO_INCREMENT PRIMARY KEY, title VARCHAR(255))')
+    cursor.executemany('INSERT INTO blog (id, title) VALUES (%s, %s);', [(i, 'Blog post #%d'% i) for i in range (1,5)])
+    conn.commit()
+
+
+if __name__ == '__main__':
+    prepare_db()
+    app.run()