Class: RazorRisk::Cassini::Applications::Microservice

Inherits:
Sinatra::Base
  • Object
show all
Includes:
RazorRisk::Core::Diagnostics::Logger, Xqsr3::Quality::ParameterChecking
Defined in:
lib/razor_risk/cassini/applications/microservice.rb

Overview

Common base-class for all microservices

Notable features:

  • provide class attribute full_description, which assumes the deriving class has defined the constants FULL_DESIGNATION SERVICE_TYPE and SHORT_DESIGNATION, that obtains a human-readable "full Cassini' service description
  • provides class method init_base_service that is used to initialise the microservice class. It must be called within a class initialiser of a derived class
  • provides class method run! that ensures class initialisation (by a derived microservice class) has been performed
  • provides global 'before' handler that:
    • trace
    • log of request details
    • before handle that:
      • sets 'Content-Type' to 'text/plain'

Direct Known Subclasses

SecurableMicroservice, UnsecuredMicroservice

Class Method Summary collapse

Class Method Details

.define_catch_all_handlers ⇒ Object

Defines catch-all handlers for all available verbs

Unless given a block, it will create catch-all handlers with a basic message and obtaining a 404. If a block given, it will be invoked with two parameters - the method name symbol and an options hash within which are the options :env, :params, :request, and :response - and should return an array consisting of the HTTP status code and the body message.

NOTE: Must be the last component defining the application!



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# File 'lib/razor_risk/cassini/applications/microservice.rb', line 153

def self.define_catch_all_handlers

    methods =   %i(delete get head link options patch post put unlink)

    if block_given?

        methods.each do |method|

            send method, // do

                yield method, env: env, params: params, request: request, response: response
            end
        end
    else

        methods.each do |method|

            send method, // do

                [ 404, "'#{env['PATH_INFO']}' [#{method.to_s.upcase}] not found" ]
            end
        end
    end
end

.full_description ⇒ Object

Provides a full description of an including type, which must have the constants FULL_DESIGNATION, SERVICE_TYPE, and SHORT_DESIGNATION.



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# File 'lib/razor_risk/cassini/applications/microservice.rb', line 138

def self.full_description

    "#{self::FULL_DESIGNATION} #{self::SERVICE_TYPE.to_s.capitalize} (#{self::SHORT_DESIGNATION})"
end

.init_base_service(host: to_nil(host_not_given_ = true), port: to_nil(port_not_given_ = true), **options) ⇒ Object

This must be invoked prior to activation of the application

Signature

  • Parameters:

    - host

    [String] The host to which the application binds. May be: nil, in which case no binding is performed and the Sinatra defaults are observed; +'0.0.0.0', in which case the server will listen on all available interfaces; a specific IP addres, in which case the server will listen only on that address. It is recommend that a specific address is used. Required

    - port

    [Integer] The port on which to activate. Required

Raises:

  • (ArgumentError) 


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# File 'lib/razor_risk/cassini/applications/microservice.rb', line 190

def self.init_base_service \
    host: to_nil(host_not_given_ = true),
    port: to_nil(port_not_given_ = true),
    **options

    trace ParamNames[ :host, :port, :options ], host, port, options

    raise ArgumentError, 'missing keyword: host' if host_not_given_

    raise ArgumentError, 'missing keyword: port' if port_not_given_
    check_parameter port, 'port', type: Integer

    init_base_service_ host, port, options
end

.run!(options = {}, &block) ⇒ Object

Refinement of ::Sinatra::Base.run! that ensures that the microservice class has been initialised



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# File 'lib/razor_risk/cassini/applications/microservice.rb', line 207

def self.run!(options = {}, &block)

    trace

    # TODO: Change this to use proper exception
    unless settings.respond_to?(:microservice_is_initialised) &&
            settings.respond_to?(:microservice_base_is_initialised)

        raise ArgumentError, "#{self} microservice application class is not initialised. Must first call #{self}.init_service()"
    end

    # Configures settings in backend service (e.g. thin, webrick)
    begin

        super do |server|

            # Set the timeout for the backend service. This prevents thin
            # from closing connections
            server.timeout = nil if server.respond_to? :timeout

            # This configures ssl in the backend service, which must be
            # thin.
            if settings.respond_to? :cassini_tls_settings

                cts = settings.cassini_tls_settings
                ssl_opts = {

                    cert_chain_file: cts[:tls_certificate_file],
                    private_key_file: cts[:tls_private_key_file],
                    verify_peer: false,
                }
                server.ssl = true
                server.ssl_options = ssl_opts
            end
        end
    rescue ::ArgumentError, ::NameError, ::NoMethodError, ::TypeError => x

        log :violation, "unexpected exception (#{x.class}): '#{x.message}': #{x.backtrace}"
        raise
    rescue => x

        log :alert, "exception (#{x.class}): '#{x.message}': #{x.backtrace}"
        raise
    end
end