Class: Rack::ECG

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/ecg.rb,
lib/rack/ecg/check.rb,
lib/rack/ecg/version.rb,
lib/rack/ecg/check/http.rb,
lib/rack/ecg/check/error.rb,
lib/rack/ecg/check/static.rb,
lib/rack/ecg/check_factory.rb,
lib/rack/ecg/check_registry.rb,
lib/rack/ecg/check/git_revision.rb,
lib/rack/ecg/check/redis_connection.rb,
lib/rack/ecg/check/migration_version.rb,
lib/rack/ecg/check/sequel_connection.rb,
lib/rack/ecg/check/active_record_connection.rb

Defined Under Namespace

Modules: Check Classes: CheckFactory, CheckRegistry

Constant Summary collapse

DEFAULT_MOUNT_AT =

Default mount path.

"/_ecg"
DEFAULT_CHECKS =

Checks enabled by default.

[:http]
DEFAULT_FAILURE_STATUS =

Default failure response status.

500
VERSION =

Library version.

"0.3.0"

Instance Method Summary collapse

Constructor Details

#initialize(app = nil, checks: DEFAULT_CHECKS, at: DEFAULT_MOUNT_AT, hook: nil, failure_status: DEFAULT_FAILURE_STATUS) ⇒ ECG

Constructs an instance of ECG Rack middleware with the specified options.

Parameters:

  • app (Object, nil) (defaults to: nil) —

    Underlying Rack application to receive unmatched requests. If unset, any unmatched requests will return a 404.

  • checks (Array<Symbol, Array<Symbol, Object>>) (defaults to: DEFAULT_CHECKS) —

    Sets and configures the checks run by this instance.

  • at (String, nil) (defaults to: DEFAULT_MOUNT_AT) —

    Path which this ECG instance handles.

  • hook (#call, nil) (defaults to: nil) —

    Callable which receives the success status and check results

  • failure_status (Integer) (defaults to: DEFAULT_FAILURE_STATUS) —

    Status code to return on check failure



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# File 'lib/rack/ecg.rb', line 28

def initialize(app = nil, checks: DEFAULT_CHECKS, at: DEFAULT_MOUNT_AT, hook: nil,
  failure_status: DEFAULT_FAILURE_STATUS)
  @app = app

  check_configuration = checks || []
  @check_factory = CheckFactory.new(check_configuration, DEFAULT_CHECKS)
  @mount_at = at || DEFAULT_MOUNT_AT

  @result_hook = hook

  @failure_response_status = failure_status
end

Instance Method Details

#call(env) ⇒ Object

Rack compatible call method. Not intended for direct usage.



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# File 'lib/rack/ecg.rb', line 42

def call(env)
  if env["PATH_INFO"] == @mount_at
    check_results = @check_factory.build_all.inject({}) do |results, check|
      results.merge(check.result.as_json)
    end

    success = check_results.none? { |check| check[1][:status] == Check::Status::ERROR }

    response_status = success ? 200 : @failure_response_status

    @result_hook&.call(success, check_results)

    response_headers = {
      "x-rack-ecg-version" => Rack::ECG::VERSION,
      "content-type" => "application/json",
    }

    response_body = JSON.pretty_generate(check_results)

    [response_status, response_headers, [response_body]]
  elsif @app
    @app.call(env)
  else
    [404, {}, []]
  end
end