Support for --no-default-middleware flag about capistrano-unicorn

[sosedoff]

@masterkain im not sure where is this supposed to go

[masterkain]

-N is a special option that can go as the last parameter, if set, during unicorn/rainbows startup: it tells to not load any default middleware in the stack. It can be used to manually load Rack::ContentLength and Rack::Chunked instead of relying on the correct -E option.

The -E option corresponds to RACK_ENV, but the effective values are 'deployment', 'none' and 'development'.

#  RACK ENVIRONMENT

Accepted values of RACK_ENV and the middleware they automatically load
(outside of RACKUP_FILE) are exactly as those in rackup(1):

* development - loads Rack::CommonLogger, Rack::ShowExceptions, and
                Rack::Lint middleware
* deployment  - loads Rack::CommonLogger middleware
* none        - loads no middleware at all, relying
                entirely on RACKUP_FILE

All unrecognized values for RACK_ENV are assumed to be
"none".  Production deployments are strongly encouraged to use
"deployment" or "none" for maximum performance.

Note the Rack::ContentLength and Rack::Chunked middlewares are also
loaded by "deployment" and "development", but no other values of
RACK_ENV.  If needed, they must be individually specified in the
RACKUP_FILE, some frameworks do not require them.

-N, \--no-default-middleware
:   Disables loading middleware implied by RACK_ENV.  This bypasses the
    configuration documented in the RACK ENVIRONMENT section, but still
    allows RACK_ENV to be used for application/framework-specific purposes.

So in production if someone wants the two content middleware loaded, it has to specify an app_env as 'deployment', but this will also tell rails that the environment is 'deployment', while it is really production, staging, etc.

AFAIK the -N switch eliminates default middlewares without interfering with RACK_ENV.

[aspiers]

@masterkain is right. This issue is essentially a very well disguised duplicate of #46. I have just been looking into #46, and independently found that capistrano-unicorn incorrectly assumes that values like staging and production are valid choices for the app_env variable, since it defaults app_env to whatever rails_env is. This is totally wrong, and will result in Rack::CommonLogger not ever being loaded for Rails staging and production environment (unless the user happens to realise this and manually set app_env to deployment).

I will produce a pull request to fix this mess. :) It will rename app_env to rack_env for maximum clarity, and bump the version to 0.2.0. It will also choose a sensible default according to rails_env, based on the recommendations from the unicorn docs quoted above.