1+ from flask import Flask , render_template , g
2+ import psycopg2
3+ import psycopg2 .extras # For dictionary cursor
4+ import os # For environment variables (recommended for credentials)
5+
6+ app = Flask (__name__ )
7+
8+ # --- Database Configuration ---
9+ # It's highly recommended to use environment variables for sensitive data in production.
10+ # For this example, we're using the provided values directly.
11+ DB_HOST = os .getenv ("DB_HOST" , "mydbserver" )
12+ DB_PORT = int (os .getenv ("DB_PORT" , 5432 ))
13+ DB_NAME = os .getenv ("DB_NAME" , "myhost" )
14+ DB_USER = os .getenv ("DB_USER" , "myuser" )
15+ DB_PASS = os .getenv ("DB_PASS" , "mypass" )
16+ DB_SSLMODE = os .getenv ("DB_SSLMODE" , "prefer" )
17+ DB_TABLE = "logs"
18+
19+ def get_db_connection ():
20+ """Establishes a new database connection."""
21+ try :
22+ conn = psycopg2 .connect (
23+ host = DB_HOST ,
24+ port = DB_PORT ,
25+ database = DB_NAME ,
26+ user = DB_USER ,
27+ password = DB_PASS ,
28+ sslmode = DB_SSLMODE
29+ )
30+ return conn
31+ except psycopg2 .Error as e :
32+ print (f"Error connecting to PostgreSQL database: { e } )
33+ return None
34+
35+ @app .before_request
36+ def before_request ():
37+ """Get a database connection before each request."""
38+ g .db_conn = get_db_connection ()
39+
40+ @app .teardown_request
41+ def teardown_request (exception ):
42+ """Close the database connection after each request."""
43+ db_conn = g .pop ('db_conn' , None )
44+ if db_conn is not None :
45+ db_conn .close ()
46+
47+ @app .route ('/' )
48+ def show_logs ():
49+ if not g .db_conn :
50+ return render_template ('logs.html' ,
51+ error_message = "Failed to connect to the database. Please check server logs and configuration." ,
52+ table_name = DB_TABLE , logs = [], columns = [])
53+
54+ logs_data = []
55+ column_names = []
56+ error = None
57+
58+ try :
59+ # Using DictCursor to get rows as dictionaries (column_name: value)
60+ with g .db_conn .cursor (cursor_factory = psycopg2 .extras .DictCursor ) as cur :
61+ cur .execute (f"SELECT * FROM { DB_TABLE } )
62+ if cur .description :
63+ column_names = [desc [0 ] for desc in cur .description ]
64+ logs_data = cur .fetchall ()
65+ except psycopg2 .Error as e :
66+ print (f"Database query error: { e } )
67+ error = f"Error fetching data from table '{ DB_TABLE } { e }
68+ # You might want to rollback if it was a write operation, g.db_conn.rollback()
69+
70+ return render_template ('logs.html' ,
71+ logs = logs_data ,
72+ columns = column_names ,
73+ table_name = DB_TABLE ,
74+ error_message = error )
75+
76+ if __name__ == '__main__' :
77+ # IMPORTANT: Set debug=False in a production environment!
78+ app .run (host = '0.0.0.0' , port = 5000 , debug = True )
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