postgres healthcheck works

anaxi/cli.py

@@ -4,7 +4,10 @@ import click
 import pyfiglet
 
 from anaxi.logging import get_anaxi_logger
-from anaxi.processes import run_cosmos_db_healthcheck_process
+from anaxi.processes import (
+    run_cosmos_db_healthcheck_process,
+    run_postgres_healthcheck_process,
+)
 
 logger = get_anaxi_logger(__name__)
 
@@ -36,3 +39,11 @@ def cosmos_db_healthcheck(cosmos_db_id):
     logger.info("Starting a Cosmos DB healthcheck.")
     run_cosmos_db_healthcheck_process(cosmos_db_id)
     logger.info("Finished the Cosmos DB healthcheck.")
+
+
+@cli.command()
+@click.option("--postgres-database", type=click.STRING, required=True)
+def postgres_healthcheck(postgres_database):
+    logger.info("Starting a Postgres healthcheck.")
+    run_postgres_healthcheck_process(postgres_database)
+    logger.info("Finished the Postgres healthcheck.")

anaxi/config.py

@@ -3,8 +3,9 @@ import pathlib
 from typing import Dict
 
 from anaxi.file_persistence import read_yaml
+from anaxi.logging import get_anaxi_logger
 
-logger = logging.getLogger()
+logger = get_anaxi_logger(__name__)
 
 
 class CosmosDBDatabaseConfig:
@@ -38,3 +39,38 @@ class CosmosDBDatabaseConfig:
             raise e
 
         return database_configs
+
+
+class PostgresDatabaseConfig:
+
+    config_root_key: str = "postgres-databases"
+
+    def __init__(self, host: str, port: int, dbname: str, user: str, password) -> None:
+        self.host = host
+        self.port = port
+        self.dbname = dbname
+        self.user = user
+        self.password = password
+
+    @classmethod
+    def from_dict(cls, a_dict) -> "PostgresDatabaseConfig":
+        return PostgresDatabaseConfig(**a_dict)
+
+    @classmethod
+    def from_yaml(cls, path: pathlib.Path) -> Dict[str, "PostgresDatabaseConfig"]:
+        yaml_contents = read_yaml(path)
+
+        postgres_contents = yaml_contents[PostgresDatabaseConfig.config_root_key]
+
+        try:
+            database_configs = {
+                db_name: PostgresDatabaseConfig.from_dict(db_config)
+                for db_name, db_config in postgres_contents.items()
+            }
+        except KeyError as e:
+            logger.error(
+                "Error reading Postgres config yaml file. The file seems malformed. Review the example in the repository."
+            )
+            raise e
+
+        return database_configs

anaxi/constants.py

@@ -11,3 +11,6 @@ class PATHS:
     cosmos_db_config_file_path: pathlib.Path = config_home_path / pathlib.Path(
         "cosmos-db.yml"
     )
+    postgres_config_file_path: pathlib.Path = config_home_path / pathlib.Path(
+        "postgres.yml"
+    )

anaxi/postgres_tools.py

@@ -0,0 +1,27 @@
+import psycopg2
+from psycopg2.sql import SQL
+
+from anaxi.config import PostgresDatabaseConfig
+
+
+def create_postgres_connection_from_config(config: PostgresDatabaseConfig):
+    return psycopg2.connect(
+        dbname=config.dbname,
+        user=config.user,
+        password=config.password,
+        host=config.host,
+        port=config.port,
+    )
+
+
+def simply_query(config: PostgresDatabaseConfig, query: SQL):
+    with psycopg2.connect(
+        dbname=config.dbname,
+        user=config.user,
+        password=config.password,
+        host=config.host,
+        port=config.port,
+    ) as db_connection:
+        cursor = db_connection.cursor()
+        cursor.execute(query)
+        return cursor.fetchall()

anaxi/processes.py

@@ -1,7 +1,10 @@
-from anaxi.config import CosmosDBDatabaseConfig
+from psycopg2.sql import SQL
+
+from anaxi.config import CosmosDBDatabaseConfig, PostgresDatabaseConfig
 from anaxi.constants import PATHS
 from anaxi.cosmos_tools import create_cosmos_client_from_config
 from anaxi.logging import get_anaxi_logger
+from anaxi.postgres_tools import simply_query
 
 logger = get_anaxi_logger(__name__)
 
@@ -25,8 +28,27 @@ def run_cosmos_db_healthcheck_process(cosmos_db_id: str) -> None:
     cosmos_client = create_cosmos_client_from_config(relevant_cosmos_db_config)
     logger.info("Client created.")
 
-    logger.info("Throwing a SELECT 1;")
+    logger.info("Sending a SELECT 1;")
     response = cosmos_client.query_databases(query="SELECT 1")
     logger.info(f"Response: {response.next()}")
 
     return
+
+
+def run_postgres_healthcheck_process(postgres_database: str) -> None:
+    logger.info("Reading Postgres config file...")
+    postgres_configs = PostgresDatabaseConfig.from_yaml(PATHS.postgres_config_file_path)
+    logger.info(f"Found file with {len(postgres_configs)} entries.")
+    try:
+        relevant_postgres_config = postgres_configs[postgres_database]
+    except KeyError as e:
+        logger.error(
+            f"Couldn't find a config entry for database with id: {postgres_database}"
+        )
+        raise e
+
+    logger.info("Connecting and sending a SELECT 1...")
+    query_result = simply_query(config=relevant_postgres_config, query=SQL("SELECT 1;"))
+    logger.info(f"Response: {query_result}")
+
+    return