Skip to main content

Asyncio plugins, components, dependency injection and configs

Project description

This is heavily inspired by Pyramid and my daily needs to fastly create and maintain microservice like applications.

a plugin mechanic

  • plugin may depend on other plugins

  • plugins yield tasks to run

  • a registry serves as a store for application components created by plugins

  • a dependency injection creates intermediate components

  • a config source is mapped to plugin specific needs

  • structlog boilerplate for json/tty logging

You bootstrap like following:

from buvar import plugin

plugin.stage("some.module.with.plugin.function")
# some.module.with.plugin.function
from buvar import context, plugin

class Foo:
    ...


async def task():
    asyncio.sleep(1)


async def server():
    my_component = context.get(Foo)
    await asyncio.Future()


# you may omit include in arguments
async def prepare(load: plugin.Loader):
    await load('.another.plugin')

    # create some long lasting components
    my_component = context.add(Foo())

    # you may run simple tasks
    yield task()

    # you may run server tasks
    yield server()

a components and dependency injection solution

Dependency injection relies on registered adapters, which may be a function, a method, a class, a classmethod or a generic classmthod.

Dependencies are looked up in components or may be provided via, arguments.

from buvar import di

class Bar:
    pass

class Foo:
    def __init__(self, bar: Bar = None):
        self.bar = bar

    @classmethod
    async def adapt(cls, baz: str) -> Foo:
        return Foo()

async def adapt(bar: Bar) -> Foo
    foo = Foo(bar)
    return foo


async def task():
    foo = await di.nject(Foo, baz="baz")
    assert foo.bar is None

    bar = Bar()
    foo = await di.nject(Foo, bar=bar)
    assert foo.bar is bar

async def prepare():
    di.register(Foo.adapt)
    di.register(adapt)

a config source

buvar.config.ConfigSource is just a dict, which merges arbitrary dicts into one. It serves a the single source of truth for application variability.

You can load a section of config values into your custom attrs class instance. ConfigSource will override values by environment variables if present.

config.toml

log_level = "DEBUG"
show_warnings = "yes"

[foobar]
some = "value"
export APP_FOOBAR_SOME=thing
import attr
import toml

from buvar import config

@attr.s(auto_attribs=True)
class GeneralConfig:
    log_level: str = "INFO"
    show_warnings: bool = config.bool_var(False)


@attr.s(auto_attribs=True)
class FoobarConfig:
   some: str


source = config.ConfigSource(toml.load('config.toml'), env_prefix="APP")

general_config = source.load(GeneralConfig)
assert general_config == GeneralConfig(log_level="DEBUG", show_warnings=True)

foobar_config = source.load(FoobarConfig, 'foobar')
assert foobar_config.some == "thing"

There is a shortcut to the above approach provided by buvar.config.Config, which requires to be subclassed from it with a distinct section attribute. If one adds a buvar.config.ConfigSource component, he will receive the mapped config in one call.

from buvar import config, plugin


@attr.s(auto_attribs=True)
class GeneralConfig(config.Config):
    log_level: str = "INFO"
    show_warnings: bool = config.bool_var(False)


@attr.s(auto_attribs=True)
class FoobarConfig(config.Config, section="foobar"):
    some: str


async def prepare(load: plugin.Loader):
    # this would by typically placed in the main entry point
    source = context.add(config.ConfigSource(toml.load('config.toml'), env_prefix="APP"))

    # to provide the adapter to di, which could also be done inthe main entry point
    await load(config)
    foobar_config = await di.nject(FoobarConfig)

a structlog

Just structlog boilerplate.

import sys

from buvar import log

log.setup_logging(sys.stdout.isatty(), general_config.log_level)

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

buvar-0.41.0.tar.gz (127.0 kB view details)

Uploaded Source

Built Distributions

buvar-0.41.0-cp38-cp38-manylinux1_x86_64.whl (547.9 kB view details)

Uploaded CPython 3.8

buvar-0.41.0-cp37-cp37m-manylinux1_x86_64.whl (485.4 kB view details)

Uploaded CPython 3.7m

File details

Details for the file buvar-0.41.0.tar.gz.

File metadata

  • Download URL: buvar-0.41.0.tar.gz
  • Upload date:
  • Size: 127.0 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/3.1.1 pkginfo/1.5.0.1 requests/2.23.0 setuptools/46.1.3 requests-toolbelt/0.9.1 tqdm/4.45.0 CPython/3.8.2

File hashes

Hashes for buvar-0.41.0.tar.gz
Algorithm Hash digest
SHA256 ce32f4cffa27679390d9b02eb59c012dc7356f0be6b869791f251f7a6f98fae6
MD5 6ae7f276fef04b891de11edfdd5928ac
BLAKE2b-256 746f5760699a61da7d6b5300d3e9df0f1749a39af339594e97eae07b5e46c44b

See more details on using hashes here.

File details

Details for the file buvar-0.41.0-cp38-cp38-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.41.0-cp38-cp38-manylinux1_x86_64.whl
  • Upload date:
  • Size: 547.9 kB
  • Tags: CPython 3.8
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/3.1.1 pkginfo/1.5.0.1 requests/2.23.0 setuptools/46.1.3 requests-toolbelt/0.9.1 tqdm/4.45.0 CPython/3.8.2

File hashes

Hashes for buvar-0.41.0-cp38-cp38-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 405a137fc5bfbe5ecb10600c656a4de89169422b527b3af4c999401b89770209
MD5 90af74fb07f4a2551ce5ac7da213bf34
BLAKE2b-256 2a15f22c9d47a0809452a95118f8ece1e179a179c46f708b20bee894c735b2b4

See more details on using hashes here.

File details

Details for the file buvar-0.41.0-cp37-cp37m-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.41.0-cp37-cp37m-manylinux1_x86_64.whl
  • Upload date:
  • Size: 485.4 kB
  • Tags: CPython 3.7m
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/3.1.1 pkginfo/1.5.0.1 requests/2.23.0 setuptools/46.1.3 requests-toolbelt/0.9.1 tqdm/4.45.0 CPython/3.8.2

File hashes

Hashes for buvar-0.41.0-cp37-cp37m-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 5b0fb53ca73952d47df339e221636b84ac2d35a51f6c5d42b3eb0f61f28efb9d
MD5 2ed04f5e4aab51bcdaf69e111b4204da
BLAKE2b-256 42bb21d6fe2dc0330a95428d9c6b866d09e4976defb474cd785ad41e0b46457c

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page