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-0.34.0.tar.gz (130.9 kB view details)

Uploaded Source

Built Distributions

buvar-0.34.0-cp38-cp38-manylinux1_x86_64.whl (553.6 kB view details)

Uploaded CPython 3.8

buvar-0.34.0-cp37-cp37m-manylinux1_x86_64.whl (491.1 kB view details)

Uploaded CPython 3.7m

File details

Details for the file buvar-0.34.0.tar.gz.

File metadata

  • Download URL: buvar-0.34.0.tar.gz
  • Upload date:
  • Size: 130.9 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-0.34.0.tar.gz
Algorithm Hash digest
SHA256 cba180056f9df4895a1b605b966e3328ea38b19c024a12bee381957edeb5504d
MD5 2876120036a9cc5db14e5fb4a2000932
BLAKE2b-256 a8c27a6d4a5f35a18d1fcb77452c78170eb010faf430c277df441d218398c6b6

See more details on using hashes here.

File details

Details for the file buvar-0.34.0-cp38-cp38-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.34.0-cp38-cp38-manylinux1_x86_64.whl
  • Upload date:
  • Size: 553.6 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-0.34.0-cp38-cp38-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 0a6fbd3344e2eda6440b54eec3ec26aeec2f6252d863ef6623956bed81cd31db
MD5 8ebf5c2fecb5eae202f56f67c22211e0
BLAKE2b-256 3f087c88db63e229b0045d9093eb46832ded1bc3efd9192c3b283cb61e558766

See more details on using hashes here.

File details

Details for the file buvar-0.34.0-cp37-cp37m-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.34.0-cp37-cp37m-manylinux1_x86_64.whl
  • Upload date:
  • Size: 491.1 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-0.34.0-cp37-cp37m-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 86a3fca59ec7286e441972d983f1695ad95f34082719b734afcd87c7dd4eaab7
MD5 97481ddc057af64e709ac2a24d8e4b24
BLAKE2b-256 07b2a6d32b8c0f6735e245ca93a1532721d8eb728d1e319c3c5d5ab4b99efe37

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