feat: Add PostgreSQL Healtcheck HTTP server

.env.dist

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+export DATABASE_HOST="localhost"
+export DATABASE_PORT="5432"
+export DATABASE_NAME="d4g"
+export DATABASE_USER="d4guser"
+export DATABASE_PASSWORD="d4gpassword"

.gitignore

@@ -160,4 +160,6 @@ dmypy.json
 cython_debug/
 
 # Precommit hooks: ruff cache
-.ruff_cache
+.ruff_cache
+.env*
+!.env.dist

main.py

@@ -0,0 +1,18 @@
+from http.server import HTTPServer
+
+from peer_session import upserver
+
+host_name = "localhost"
+server_port = 8080
+
+if __name__ == "__main__":
+    web_server = HTTPServer((host_name, server_port), upserver.UpServer)
+    print(f"Server listening http://{host_name}:{server_port}")
+
+    try:
+        web_server.serve_forever()
+    except KeyboardInterrupt:
+        pass
+
+    web_server.server_close()
+    print("Server stopped.")

peer_session/db.py

@@ -0,0 +1,50 @@
+import logging
+import os
+import time
+
+import psycopg2
+
+
+class DB:
+    def __init__(self) -> None:
+        self.connection = None
+        self.configure()
+        self.connect()
+
+    def configure(self) -> None:
+        """Configure the connection to the database."""
+        self.database_host = os.environ.get("DATABASE_HOST")
+        self.database_port = os.environ.get("DATABASE_PORT")
+        self.database_name = os.environ.get("DATABASE_NAME")
+        self.database_user = os.environ.get("DATABASE_USER")
+        self.database_password = os.environ.get("DATABASE_PASSWORD")
+
+        logging.debug(f"Connecting to host {self.database_host}")
+        logging.debug(f"port : {self.database_port}")
+        logging.debug(f"database : {self.database_name}")
+        logging.debug(f"user : {self.database_user}")
+
+    def connect(self) -> None:
+        """Connect to a PostgreSQL database."""
+        try:
+            if self.connection is None:
+                self.connection = psycopg2.connect(
+                    database=self.database_name,
+                    user=self.database_user,
+                    password=self.database_password,
+                    host=self.database_host,
+                    port=self.database_port,
+                )
+        except psycopg2.DatabaseError:
+            logging.exception
+        finally:
+            logging.info("Database connection opened successfully.")
+
+    def healthcheck(self) -> float:
+        """Make sure the Postgres database is reachable."""
+        start_time = time.perf_counter()
+        self.connection.cursor().execute("SELECT 1")
+        end_time = time.perf_counter()
+
+        elapsed_time = round((end_time - start_time) * 1000, 3)
+        return elapsed_time

peer_session/upserver.py

@@ -0,0 +1,32 @@
+from http.server import BaseHTTPRequestHandler
+
+from peer_session.db import DB
+
+
+class UpServer(BaseHTTPRequestHandler):
+    def do_get(self) -> None:
+        if self.path == "/up":
+            self.do_UP()
+            return
+
+        self.send_response(420)
+        self.send_header("Content-type", "text/html")
+        self.end_headers()
+        self.wfile.write(
+            bytes("He who breaks a thing has lost the path of wisdom.", "utf-8"),
+        )
+
+    def do_up(self) -> None:
+        database = DB()
+        try:
+            time_ms = database.healthcheck()
+            self.send_response(200)
+            self.send_header("Content-type", "json")
+            self.end_headers()
+            self.wfile.write(bytes(f'{{"up": true, "time": "{time_ms}ms"}}', "utf-8"))
+        except Exception:
+            self.send_response(500)
+            self.send_header("Content-type", "json")
+            self.end_headers()
+            self.wfile.write(bytes('{"up": false, "time": 0}', "utf-8"))
+            return

pyproject.toml

@@ -3,19 +3,16 @@ requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
-name = "python_template"
+name = "peer-session"
 version = "0.1.0"
-description = "Template"
+description = "This repository is purely for educational purposes."
 authors = ["DataForGood"]
-license = " MIT"
+license = "MIT"
 readme = "README.md"
 
 [tool.poetry.dependencies]
 python = "^3.10"
-# numpy = "^1.21.1"
-# pandas = "^1.1.1"
-# jupyter = "^1.0.0"
-# ipykernel = "^5.3.4"
+psycopg2-binary = "^2.9.9"
 
 [tool.poetry.group.dev.dependencies]
 pre-commit = "^2.20.0"