Merged code from external repo and refactored folder structure

Author: rjtokenring

README.md

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+# Installation
+
+To build package:
+* pip install build
+* python -m build

appslab_modules/db_storage/__init__.py

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+from .database_storage import DatabasePersistence, DatabaseRetrieval

appslab_modules/db_storage/compose.yaml

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+services:
+  db_storage:
+    image: influxdb:2.7 # or a different version
+    ports:
+      - "127.0.0.1:8086:8086"
+    volumes:
+      - ./influxdb_data:/app/db_storage/data
+    environment:
+      DOCKER_INFLUXDB_INIT_MODE: setup
+      DOCKER_INFLUXDB_INIT_USERNAME: admin
+      DOCKER_INFLUXDB_INIT_PASSWORD: Arduino15
+      DOCKER_INFLUXDB_INIT_ORG: arduino
+      DOCKER_INFLUXDB_INIT_BUCKET: db_storage
+      DOCKER_INFLUXDB_INIT_ADMIN_TOKEN: 392edbf2-b8a2-481f-979d-3f188b2c05f0

appslab_modules/db_storage/database_storage.py

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+from influxdb_client import InfluxDBClient, Point, WritePrecision
+from influxdb_client.client.write_api import SYNCHRONOUS
+import yaml
+import time
+
+class _InfluxPersistence:
+    def __init__(self, host:str = "db_storage", port:int = 8086):
+        self.name = "db_storage"
+        self.host = host
+        self.port = port
+        infra = self.load_default_infra()
+        env_dict = infra['services']['db_storage']['environment']
+        self.url = f"http://{self.host}:{self.port}"
+        self.token =  env_dict['DOCKER_INFLUXDB_INIT_ADMIN_TOKEN']
+        self.org =  env_dict['DOCKER_INFLUXDB_INIT_ORG']
+        self.bucket =  env_dict['DOCKER_INFLUXDB_INIT_BUCKET']
+        self._connect()
+
+    def load_default_infra(self):
+        with open("compose.yaml", "r") as file:
+            config = yaml.safe_load(file)
+            return config
+
+    def _connect(self):
+        try:
+            with InfluxDBClient(url=self.url, token=self.token, org=self.org) as client:
+                self.client = client
+                self.write_api = client.write_api(write_precision=WritePrecision.MS)
+                self.query_api = client.query_api()
+                #Test connection
+                query = f'from(bucket: "{self.bucket}") |> range(start: -1m)'
+                self.query_api.query(query)
+                print("Connection and query successful!")
+
+        except Exception as e:
+            print(f"Error: {e}")
+
+    def close(self):
+        self.client.close()        
+
+class DatabasePersistence(_InfluxPersistence):
+    def __init__(self, host:str, port:int):
+        super().__init__(host, port)
+
+    def write_sample(self, measurement_name :str, measure :str, value :any, ts :int = 0):
+        try:
+            if ts <= 0:
+                ts = int(time.time_ns() / 1000000)
+            point = Point(measurement_name).field(measure, value).time(ts, WritePrecision.MS)
+
+            self.write_api.write(bucket=self.bucket, record=point)
+            print("Data written successfully!")
+
+        except Exception as e:
+            print(f"Error: {e}")
+
+class DatabaseRetrieval(_InfluxPersistence):
+    def __init__(self, host:str, port:int):
+        super().__init__(host, port)
+
+    def read_last_sample(self, measurement_name :str, measure :str):
+        try:
+            query = f"""
+            from(bucket: "{self.bucket}")
+            |> range(start: -1d) # look back 1 day
+            |> filter(fn: (r) => r["_measurement"] == "{measurement_name}")
+            |> filter(fn: (r) => r["_field"] == "{measure}")
+            |> last()
+            """
+
+            result = self.query_api.query(org=self.org, query=query)
+
+            if result:
+              for table in result:
+                  for record in table.records:
+                      return record.get_time(), record.get_value()
+            else:
+                print(f"No data found for {measurement_name} and {measure}")
+
+        except Exception as e:
+            print(f"Error: {e}")
+             

appslab_modules/db_storage/module_config.yaml

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+name: db_storage
+module_description: "Simplified database storage layer for Arduino sensor data"

appslab_modules/db_storage/test_database_storage.py

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+from database_storage import DatabasePersistence
+import time
+
+## TODO define unit test properly, now just a simple main
+
+db = DatabasePersistence(host="localhost")
+
+i = 0
+while i < 2:
+    db.write_sample("test_measurement", 1234)
+    time.sleep(1)
+    i += 1
+
+time.sleep(1)
+db.close()
+print("Test complete!")