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-0.23.1.tar.gz (126.8 kB view details)

Uploaded Source

Built Distributions

buvar-0.23.1-cp38-cp38-manylinux1_x86_64.whl (435.1 kB view details)

Uploaded CPython 3.8

buvar-0.23.1-cp37-cp37m-manylinux1_x86_64.whl (372.6 kB view details)

Uploaded CPython 3.7m

File details

Details for the file buvar-0.23.1.tar.gz.

File metadata

  • Download URL: buvar-0.23.1.tar.gz
  • Upload date:
  • Size: 126.8 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/1.13.0 pkginfo/1.5.0.1 requests/2.22.0 setuptools/41.0.1 requests-toolbelt/0.9.1 tqdm/4.32.1 CPython/3.7.3

File hashes

Hashes for buvar-0.23.1.tar.gz
Algorithm Hash digest
SHA256 405707a7396c1b1714cdba621fe9247ab61b8a784000a69d67fc13c72e55d1d7
MD5 a4de160a3f0db1901903f88765838ea6
BLAKE2b-256 ec0fa7e69e80b18ff70db4f71959e3bbf788a65196502ab1af0bbe550cabeca6

See more details on using hashes here.

File details

Details for the file buvar-0.23.1-cp38-cp38-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.23.1-cp38-cp38-manylinux1_x86_64.whl
  • Upload date:
  • Size: 435.1 kB
  • Tags: CPython 3.8
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/1.13.0 pkginfo/1.5.0.1 requests/2.22.0 setuptools/41.0.1 requests-toolbelt/0.9.1 tqdm/4.32.1 CPython/3.7.3

File hashes

Hashes for buvar-0.23.1-cp38-cp38-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 83e8753f7d868d25bd70b957801917762cfeba6d9b041878f964ce91e1276c9c
MD5 fd520f9f7f87461ef7be48cf3f0680a0
BLAKE2b-256 43baadb92fc16818358c750713fef6c9405bc7a9e92ad1a7e4bb15a693a80413

See more details on using hashes here.

File details

Details for the file buvar-0.23.1-cp37-cp37m-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.23.1-cp37-cp37m-manylinux1_x86_64.whl
  • Upload date:
  • Size: 372.6 kB
  • Tags: CPython 3.7m
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/1.13.0 pkginfo/1.5.0.1 requests/2.22.0 setuptools/41.0.1 requests-toolbelt/0.9.1 tqdm/4.32.1 CPython/3.7.3

File hashes

Hashes for buvar-0.23.1-cp37-cp37m-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 9f7209cd0fa26ff1a26716b691818cc0bdf8b9e0380091b027c2065b51633174
MD5 cba2b03abe5869a02e3faea6d0d7842b
BLAKE2b-256 d5e03b174348582ca75eba136d73b6ddf190eb82026fc8033d20911eaa683a28

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