@architect/plugin-external-tables

Enable access to external DynamoDB tables from other Architect projects, legacy Architect projects, and non-Architect projects

Install

npm i @architect/plugin-external-tables

Add this line to your Architect project manifest:

# app.arc
@plugins
architect/plugin-external-tables

Then follow the directions below for @external-tables.

Note: this plugin currently only supports enabling access to tables in the same region. For example: if your app is in us-west-1, this plugin will not enable access to external tables in us-east-1.

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@external-tables

The @external-tables pragma enables access to DynamoDB tables managed by current and legacy versions of Architect, and an arbitrary number of physical DynamoDB table names. Usage for each:

• Other Architect tables
  • Each entry is a named list, where the name is the @app name of the external Architect app, and the list is of tables to which you'd like to provide access
  • In the example below, resources in the my-app Architect app would get access three external tables:
    • The analytics + data tables from the app named an-arc-app, and
    • The usage table from the app named another-arc-app
• Legacy Architect tables
  • Each entry is a string; legacy Arc tables follow convention-based naming, and require a special variable, like so: old-app-$arc_stage-users; this breaks down as follows:
    • old-app - the @app name of your legacy Arc app
    • $arc_stage - a special string used by this plugin to identify the deployment stage (staging or production) of the table
    • users - the @tables name of your legacy table
• Physical table names
  • Each entry is a string; any arbitrary table name can be used here, e.g. user-data
  • Note: physical table names are not to be confused with ARNs; DynamoDB ARNs cannot be used by this plugin

Table uniqueness

Although tables may have various unique physical names, each resolved logical table name must be unique across @tables, @arc-tables, and @other-tables when using this plugin.

If a conflict is found, this plugin will error. For example, you may have the following literal table names:

• MyAppStaging-UsersTable-ABC123 - a table named users managed by the Architect app named my-app
• AnArcAppProduction-UsersTable-DEF456 - a table named users managed by another Architect app named an-arc-app
• another-arc-app-staging-users - a table named users originally created by a legacy Architect app named another-arc-app
• users - a table just named users created outside of Architect

Because of how Architect manages automatic service discovery for tables with @architect/functions all four of these tables would be in conflict with the logical table name users (e.g. arc.tables().users.get()).

Examples

An example providing an Architect app access to the internal table named products, and five external tables: analytics, data, usage, users, and user-data.

@app
my-app

@tables                   # tables managed by this Architect app
products
  id *String

@external-tables          # tables managed by other Arc apps in the same region
an-arc-app                # app name
  analytics               # table names...
  data
another-arc-app           # another app
  usage
old-app-$arc_stage-users  # legacy Arc table
user-data                 # DynamoDB table not created/managed by Arc

This example would not work due to table name uniqueness conflicts enumerated above:

@app
broken-tables

@tables                       # tables managed by this Architect app
products
  id *String

@external-tables
an-arc-app
  products                    # conflicts with @tables products
another-arc-app
  products                    # conflicts with @tables products
old-app-$arc_stage-products   # conflicts with @tables products
products                      # conflicts with @tables products