gitlab-org--gitlab-foss/lib/gitlab/middleware/basic_health_check.rb

49 lines
1.6 KiB
Ruby

# frozen_string_literal: true
# This middleware provides a health check that does not hit the database. Its purpose
# is to notify the prober that the application server is handling requests, but a 200
# response does not signify that the database or other services are ready.
#
# See https://thisdata.com/blog/making-a-rails-health-check-that-doesnt-hit-the-database/ for
# more details.
module Gitlab
module Middleware
class BasicHealthCheck
# This can't be frozen because Rails::Rack::Logger wraps the body
# rubocop:disable Style/MutableConstant
OK_RESPONSE = [200, { 'Content-Type' => 'text/plain' }, ["GitLab OK"]]
EMPTY_RESPONSE = [404, { 'Content-Type' => 'text/plain' }, [""]]
# rubocop:enable Style/MutableConstant
HEALTH_PATH = '/-/health'
def initialize(app)
@app = app
end
def call(env)
return @app.call(env) unless env['PATH_INFO'] == HEALTH_PATH
# We should be using ActionDispatch::Request instead of
# Rack::Request to be consistent with Rails, but due to a Rails
# bug described in
# https://gitlab.com/gitlab-org/gitlab-foss/issues/58573#note_149799010
# hosts behind a load balancer will only see 127.0.0.1 for the
# load balancer's IP.
request = Rack::Request.new(env)
return OK_RESPONSE if client_ip_whitelisted?(request)
EMPTY_RESPONSE
end
def client_ip_whitelisted?(request)
ip_whitelist.any? { |e| e.include?(request.ip) }
end
def ip_whitelist
@ip_whitelist ||= Settings.monitoring.ip_whitelist.map(&IPAddr.method(:new))
end
end
end
end