CLI

Propan has its own built-in CLI tool for your maximum comfort as a developer.

Thanks to typer and watchfiles. Their work is the basis of this tool.

$ propan --help

Usage: propan [OPTIONS] COMMAND [ARGS]...

  Generate, run, and manage Propan apps for greater development experience

Options:
  --version             Show current platform, python and propan version
  --install-completion  Install completion for the current shell.
  --show-completion     Show completion for the current shell, to copy it or
                        customize the installation.
  --help                Show this message and exit.

Commands:
  create  Create a new Propan project at [APPNAME] directory
  run     Run [MODULE:APP] Propan application

Project generation

To start a new project template, you can use the standard template Propan:

$ propan create async rabbit app

Create Rabbit Propan project template at: ./app

The template includes:

• a simple yet working Dockerfile
• docker-compose.yml configured for development
• a project configured to use pydantic as the environment manager

Reloading the project

Thanks to watchfiles, written in Rust, you can work with your project easily. Edit the code as much as you like - the new version has already been launched and is waiting for your requests!

$ propan run app.app.serve:app --reload

2023-04-10 23:39:41,140 INFO     - Started reloader process [115536] using WatchFiles
2023-04-10 23:39:41,145 INFO     - Propan app starting...
2023-04-10 23:39:41,151 INFO     - `base_handler` waiting for messages
2023-04-10 23:39:41,152 INFO     - Propan app started successfully! To exit press CTRL+C

Environment Management

You can pass any custom flags and launch options to the Propan CLI even without first registering them. Just use them when launching the application - and they will be right in your environment.

Use this option to select environment files, configure logging, or at your discretion.

For example, we will pass the .env file to the context of our application:

$ propan run serve:app --env=.env.dev

2023-04-10 23:39:41,145 INFO     - Propan app starting...
2023-04-10 23:39:41,151 INFO     - `base_handler` waiting for messages
2023-04-10 23:39:41,152 INFO     - Propan app started successfully! To exit press CTRL+C

RedisRabbitMQKafkaSQSNATS

from propan import PropanApp, RedisBroker
from propan.annotations import ContextRepo
from pydantic_settings import BaseSettings

broker = RedisBroker()

app = PropanApp(broker)

class Settings(BaseSettings):
    host: str = "redis://localhost:6379"

@app.on_startup
async def setup(env: str, context: ContextRepo):
    settings = Settings(_env_file=env)
    await broker.connect(settings.host)
    context.set_global("settings", settings)

from propan import PropanApp, RabbitBroker
from propan.annotations import ContextRepo
from pydantic_settings import BaseSettings

broker = RabbitBroker()

app = PropanApp(broker)

class Settings(BaseSettings):
    host: str = "amqp://guest:guest@localhost:5672/"

@app.on_startup
async def setup(env: str, context: ContextRepo):
    settings = Settings(_env_file=env)
    await broker.connect(settings.host)
    context.set_global("settings", settings)

from propan import PropanApp, KafkaBroker
from propan.annotations import ContextRepo
from pydantic_settings import BaseSettings

broker = KafkaBroker()

app = PropanApp(broker)

class Settings(BaseSettings):
    host: str = "localhost:9092"

@app.on_startup
async def setup(env: str, context: ContextRepo):
    settings = Settings(_env_file=env)
    await broker.connect(settings.host)
    context.set_global("settings", settings)

from propan import PropanApp, SQSBroker
from propan.annotations import ContextRepo
from pydantic_settings import BaseSettings

broker = SQSBroker()

app = PropanApp(broker)

class Settings(BaseSettings):
    host: str = "http://localhost:9324"

@app.on_startup
async def setup(env: str, context: ContextRepo):
    settings = Settings(_env_file=env)
    await broker.connect(settings.host)
    context.set_global("settings", settings)

from propan import PropanApp, NatsBroker
from propan.annotations import ContextRepo
from pydantic_settings import BaseSettings

broker = NatsBroker()

app = PropanApp(broker)

class Settings(BaseSettings):
    host: str = "nats://localhost:4222"

@app.on_startup
async def setup(env: str, context: ContextRepo):
    settings = Settings(_env_file=env)
    await broker.connect(settings.host)
    context.set_global("settings", settings)

Note

Note that the env parameter was passed to the setup function directly from the command line

All passed values can be of type bool, str or list[str].

In this case, the flags will be interpreted as follows:

$ propan run app:app --flag       # flag = True
$ propan run app:app --no-flag    # flag = False
$ propan run app:app --my-flag    # my_flag = True
$ propan run app:app --key value  # key = "value"
$ propan run app:app --key 1 2    # key = ["1", "2"]

You can use them both individually and together in unlimited quantities.