rack-graphql
rack-graphql is designed to build ruby services with graphql api. It provides /graphql endpoint and can handle subscriptions and multiplex.
It works on pure rack and none of ActionController/ActionDispatch/ActionPack or Sinatra is required. By default it provides health route on /health and /, which can be disabled.
It can be used together with rails to not make graphql requests be routed with ActionDispatch or more pure ruby apps.
Installation
Add this line to your application's Gemfile:
gem 'rack-graphql'Usage example
Add following to your config.ru file:
run RackGraphql::Application.call(
schema: YourGraqphqlSchema, # required
app_name: 'your-service-name', # optional, used for health endpoint content
context_handler: YourGraphqlContextHandler, # optional, empty `proc` by default
log_exception_backtrace: !A9n.env.production?, # optional, `false` default
# `true` when `RACK_GRAPHQL_LOG_EXCEPTION_BACKTRACE` env var is set to `'1'` or `'true'`
health_route: true, # optional, true by default
health_on_root_path: health_route, # optional, health_route value by default (mind map '/' is covering '/any/path-123')
root_path_app: YourDashboardApp, # optional
logger: A9n.logger, # optional, not set by default
error_status_code_map: { IamTeapotError => 418 }, # optional
re_raise_exceptions: true, # optional, false by default
request_epilogue: -> { ActiveRecord::Base.connection_handler.clear_active_connections! }
)context_handler can be a class, object or proc. It must respond to call method taking env as an argument. It is supposed to decode or transform request properties to graphql context (eg. jwt token to user object, as shown on an example below).
Example: using context handler for JWT authentication
class GraphqlContextHandler
class << self
def call(env)
payload = decode_payload(env)
graphql_context_hash(payload)
end
private
def graphql_context_hash(payload)
{
current_user: current_user(payload)
}
end
def decode_payload(env)
jwt = env["HTTP_AUTHORIZATION"].to_s.split(' ').last
return if jwt.blank?
DecodeJwt.call(jwt) || {}
end
def current_user(payload)
return unless payload
return unless payload['user_id']
UserRepo.find_by_id(payload['user_id'])
end
end
endLogging exception backtrace
RackGraphql catches all errors and respond with 500 code. By default it adds exception backtrace to the response body. If you don't want to have the backtrace in the response set:
RackGraphql.log_exception_backtrace = false
Error tracking/reporting
To respect the graphql spec, all errors need to be returned as json and rack-graphql catches all exceptions and does NOT re-raise them. You can change this behavior via re_raise_exceptions argument.
Because of this, using error tracking middleware (use Sentry::Rack::CaptureExceptions, use Raven::Rack) does not take any effect for graphql requests.
To use Sentry or other reporting tool for graphql queries, you should handle it on graphql schema level:
class MySchema < GraphQL::Schema
rescue_from StandardError do |e, obj, args, ctx, field|
extra = {
args: args,
field: field.inspect,
context: ctx
}
Sentry.capture_exception(e, extra: extra)
# re-raise to be handled by rack middleware
raise
# or return execution error
::GraphQL::ExecutionError.new(
exception.class.to_s,
options: { "http_status" => 500 },
extensions: {
"code" => exception.class.to_s,
"http_status" => 500,
"details" => exception.inspect
}
)
end
endContributing
Bug reports and pull requests are welcome on GitHub at https://github.com/RenoFi/rack-graphql. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.