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-0.25.0.tar.gz (129.1 kB view details)

Uploaded Source

Built Distributions

buvar-0.25.0-cp38-cp38-manylinux1_x86_64.whl (438.1 kB view details)

Uploaded CPython 3.8

buvar-0.25.0-cp37-cp37m-manylinux1_x86_64.whl (375.6 kB view details)

Uploaded CPython 3.7m

File details

Details for the file buvar-0.25.0.tar.gz.

File metadata

  • Download URL: buvar-0.25.0.tar.gz
  • Upload date:
  • Size: 129.1 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-0.25.0.tar.gz
Algorithm Hash digest
SHA256 b1775534e1a51879634e27c9f037a735b23412e786e37648b77a8394d33a6ad6
MD5 dde43483f01f83211f56ada5a453be25
BLAKE2b-256 1bf5e03c07739d4ec135363f30d2b03e8c3eee6b1decb3dedb965d95ae00f7e5

See more details on using hashes here.

File details

Details for the file buvar-0.25.0-cp38-cp38-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.25.0-cp38-cp38-manylinux1_x86_64.whl
  • Upload date:
  • Size: 438.1 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-0.25.0-cp38-cp38-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 0866524d460c504627c45c48534fec77518474a2e0fa0c8201f97f8ab3a5cfef
MD5 2b0c7e7a81343a12580a8bf2b702d053
BLAKE2b-256 1230d18b3be439a62719e3739ed5e0085cbb7929d6dcf10cc9de5db54564e604

See more details on using hashes here.

File details

Details for the file buvar-0.25.0-cp37-cp37m-manylinux1_x86_64.whl.

File metadata

  • Download URL: buvar-0.25.0-cp37-cp37m-manylinux1_x86_64.whl
  • Upload date:
  • Size: 375.6 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-0.25.0-cp37-cp37m-manylinux1_x86_64.whl
Algorithm Hash digest
SHA256 afd775fbb9c15adebc8df45948765cd4bb0ced1b43b331ebbd9fefd181bd4fd9
MD5 edcbe2a35895bd963629413dcc771b88
BLAKE2b-256 3a3f0297893faa5627b9f11016853dc06a3bb1969b4d109d1108e425784e851e

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