refactor(env): #22: parse data for connection string of orm from env

.env.example

@@ -0,0 +1,6 @@
+# Database
+POSTGRES_HOST=tobemodified
+POSTGRES_PORT=tobemodified
+POSTGRES_DB=tobemodified
+POSTGRES_USER=tobemodified
+POSTGRES_PASSWORD=tobemodified

README.md

@@ -32,7 +32,8 @@ When the project configuration is finished, click Build to build the project.
 ### Project run
 
 #### Before launching web server:
-- Run the database container via docker compose command `docker compose -f docker-compose.dev.yaml up -d` from workspace.
+- Run the database container via docker compose command `docker compose up -d` from workspace.
+- Import environment variables declared in the `.env` file while in the dev container and using the command `export $(grep -v '^#' .env | xargs)`. If the file containing the environment variables is named something other than `.env`, you should modify the command to specify the correct name.
 
 To launch the executable, click Launch in the CMake extension.
 <p style="text-align: center;"><img src="docs/images/cmakeLaunch.png" alt="cmakeLaunch" width="400"/></p>

docker-compose.dev.yaml → docker-compose.yml

@@ -4,11 +4,11 @@ services:
     container_name: postgresql
     image: postgres:14-alpine
     env_file:
-      - .env.dev
+      - .env
     volumes:
       - postgresql-data:/var/lib/postgresql/data
     ports:
       - "5432:5432"
 
 volumes:
-  postgresql-data:
+  postgresql-data:

src/data/alembic.ini

@@ -81,14 +81,6 @@ path_separator = os
 # are written from script.py.mako
 # output_encoding = utf-8
 
-# database URL.  This is consumed by the user-maintained env.py script only.
-# other means of configuring database URLs may be customized within the env.py
-# file.
-
-# TODO(https://github.com/TourmalineCore/to-dos-api-cpp/issues/22): parse connection data variables from .env or .env.dev
-sqlalchemy.url = postgresql://postgres:admin@localhost/to-dos-api-cpp_db
-
-
 [post_write_hooks]
 # post_write_hooks defines scripts or Python functions that are run
 # on newly generated revision scripts.  See the documentation for further

src/data/migrations/env.py

@@ -29,6 +29,17 @@
 # my_important_option = config.get_main_option("my_important_option")
 # ... etc.
 
+def get_database_url():
+    """Getting the Database URL from Environment Variables"""
+    user = os.getenv('POSTGRES_USER')
+    password = os.getenv('POSTGRES_PASSWORD')
+    host = os.getenv('POSTGRES_HOST')
+    port = os.getenv('POSTGRES_PORT')
+    name = os.getenv('POSTGRES_DB')
+
+    return f"postgresql://{user}:{password}@{host}:{port}/{name}"
+
+url = get_database_url()
 
 def run_migrations_offline() -> None:
     """Run migrations in 'offline' mode.
@@ -42,7 +53,6 @@ def run_migrations_offline() -> None:
     script output.
 
     """
-    url = config.get_main_option("sqlalchemy.url")
     context.configure(
         url=url,
         target_metadata=target_metadata,
@@ -61,6 +71,8 @@ def run_migrations_online() -> None:
     and associate a connection with the context.
 
     """
+    config.set_main_option('sqlalchemy.url', url)
+
     connectable = engine_from_config(
         config.get_section(config.config_ini_section, {}),
         prefix="sqlalchemy.",

src/main.cpp

@@ -14,14 +14,13 @@ int main()
     {
         // TODO(https://github.com/TourmalineCore/to-dos-api-cpp/issues/27): add migration update on startup
 
-        // TODO(https://github.com/TourmalineCore/to-dos-api-cpp/issues/22): parse that variables from .env or .env.dev
-        const std::string user = "postgres";
-        const std::string password = "admin";
-        const std::string db_name = "to-dos-api-cpp_db";
-        const std::string host = "localhost";
-        const unsigned port = 5432;
+        const std::string user = std::getenv("POSTGRES_USER");
+        const std::string password = std::getenv("POSTGRES_PASSWORD");
+        const std::string db_name = std::getenv("POSTGRES_DB");
+        const std::string host = std::getenv("POSTGRES_HOST");
+        const std::string port = std::getenv("POSTGRES_PORT");
 
-        std::string conninfo = "host=" + host + " port=" + std::to_string(port) + " dbname=" + db_name + " user=" + user + " password=" + password;
+        std::string conninfo = "host=" + host + " port=" + port + " dbname=" + db_name + " user=" + user + " password=" + password;
 
         std::unique_ptr<odb::database> db(new odb::pgsql::database(conninfo));