AppBuilder implements an Microservice Archtecture with a number of containerized services. Services are run in docker containers, typically deployed through docker swarm. Services are typically written in NodeJs based off of the nodejs docker image.
AB Services
ab_service_api_sails
This is the main api gateway for AppBuilder. It uses sailsjs. Here we process incoming requests, including authentication and resolving the tenant. The actually request is then passed off to one or more service to do the actual work.
Documentation on our api endpoints can be fount in the README
Sails can return tempalted html, but most of our html is served statically from ab_service_web.
ab_service_web
This is our nginx web server. It’s based on the nginx docker image. It serves static assets, including the majority of our html.
We maintain both a master and develop branch of ab_service-web, both get built into docker images. The main difference is in the webpack build. master contains compressed and minified code, while develop is uncompressed and unmimified. master should be production ready code.
ab_platform_web
This is the main framework for displaying AppBuilder in a web browser. It will create a factory (ABFactory) which use to generate the Apps based off of the definitions and handle most functions including communication with the server. The web platform extends appbuilder_classes_core.
The main UI framework we use is Webix.
plugin_ABDesigner
This is a core plugin that enables users with Builder permission, to create and edit Apps within the system. This, like all plugins, recieves the ABFactory from ab_platform_web.
ab_service_appbuilder
This service handles operations that read and write data to/from the tenant’s custom tables as defined in their app definitions.
ab_service_custom_reports
This service renders and serves html reports. These include data from the tenant and custom buisness. It intended for reports or templates that are hard to model using the ABDesigner. Reports are written as ejs templates and custom logic to get the necessary data.
ab_service_definition_manager
This service manages the appbuilder defintions for each tenant. Definitions define many things including the display of each apps and the custom database tables. Typically definions are created and editied using the ABDesigner plugin.
Definitions are stored as JSON in the appbuilder_definion table.
ab_service_log_manager
This service maintains an audit log of data changes, including who changed what when. Logs are stored in the SITE_ROWLOG table.
ab_service_file_processor
The serivec manages uploaded files.
ab_service_process_manager
This service runs processes as defined in the definions. Process are modeled in the ABDesigner plugin, using bpmn.io notation. Process manager will trigger and run various process tasks as defined.
ab_service_relay
This service decrypts and triggers reqeust that come in from a MCC relay servers. Response are encrypted before being sent out.
ab_service_tenant_manager
This service manages configuration settings for individual tenants.
ab_service_user_manager
This service manages users, including setting and verifying passwords.
ab_service_db
This is a MariaDB database based off of the official image. It includes the basic schema for our SITE_ tables, as well as the appbuilder_definition table.
It also includes some data, for example, the definitions for our Site Adminstration App. Each tenant has it own database.
The SITE_ tables will have the same schema for each tenant, but tenants will also have custom generated tables based on theoir defintions.
Changes to our SITE_ tables and basic appbuilder_definions are handled by ab_migartion_manager, which applies ordered patches to new and existing databases.
Shared Components
ab-utils
This is shared set of utilities used in each of our services. This is where implement cote, which handles communication between our services.
ab-utils also includes the mysql library for interacting with the database.
More details about the utilities is documented in it’s READNE.
We publish ab-utils to npm and included as a dependency in each service.
appbuilder_class_core
This is a shared set of clases that get extended in a different platforms. For example ABFactoryCore is defined here. ab_platform_web extends this as ABFactory to include specific functionality used only on the web.
appbuilder_platform_service also extends this and creates it’s own ABFactory class which includes functionality needed on the server.
Note: Though not discussed here, this is also shared with ab_platform_mobile and test_pwa (experimental mobile platform).
appbuilder_platform_service
This is a shared codebase used in many of our services. It many function is to create an ABFactory used by the service. An ABFactory is unique to each tenant, and will ensure that the correct database is used forany queries.
Currently we use Objection.js and Knex.js to work with the Database.
Other
Redis
We run an instance of Redis. We run the official redis docker image.
This is used by cote for service discovery.
It is also used sails as the session store and socket store.