bjoern-cli

bjoern-cli is a command line wrapper to serve a Python WSGI app with bjoern server. It exists because the only way to serve an app with bjoern is to import it in your code and configure the entrypoint to launch the server. This way to serve bjoern ties your application code to a webserver implementation and upgrading or changing the server becomes a change in application code.

With bjoern-cli you can configure your application to expose the WSGI app object and serve it from command line. It also provides a convenient wrappers to selectively use features that are compiled in bjoern and ignore those that aren't.

Installation

If you ship your app in a docker container then the recommended way is to install bjoern-cli in the container context separate from the application. This makes it easier to upgrade the server or simply swap it out for something inferior. Alternatively you can also use it as an app dependency. If that is what you want to do — and you really shouldn't be doing it like this — add bjoern-cli in your setup.py or requirements.txt file. If you are using the pathetically slow, pain in the ass tool then put it in Pipenv file.

pip install bjoern-cli

Usage

Assuming that your application api is exposed by module my_app.web, you can start the server with

bjoern-cli --module my_app.web --app api

Following command line parameters are available:

  --host host            Host name or the IP address to bind with (default: 0.0.0.0)
  --port port            Port number to bind with (default: 8787)
  --module module        Importable python module that exposes the WSGI app (default: None)
  --app app              Name of the app as exposed by the module (default: app)
  --statsd-enable        Expose metrics to statsd (default: False)
  --statsd-host host     Address of the Statsd collector (default: 127.0.0.1)
  --statsd-port port     Port of the Statsd collector (default: 8125)
  --statsd-ns namespace  Statsd metrics namespace (default: bjoern)
  --statsd-tags tags     Comma separated list of tags to expose with metrics (default: [])

Features than can be selectively compiled into bjoern are appropriately indicated in the argument description. If a feature is not available its parameter description is followed by "Ignored since bjoern is not compiled with this feature".

Caveat

Note that bjoern-cli fetches bjoern from github instead of PyPI. This is necessary at this time because the version of bjoern with Statsd support is not tagged and pulling from github remains the only way to install it. This also means that bjoern will be compiled when you install bjoern-cli and you are expected to setup proper feature flags in the installation environment. If you are installing bjoern-cli in a docker container then adding the following snippet to the Dockerfile should enable statsd and tags support.

ENV BJOERN_WANT_STATSD=true BJOERN_WANT_STATSD_TAGS=true

If you are in a shell then simply run

BJOERN_WANT_STATSD=true BJOERN_WANT_STATSD_TAGS=true pip install bjoern-cli

You can consult setup.py to know the version of bjoern that will be installed.