feat: introduce role based access control

packages/backend/src/db/migrations/20230615205857_create_permissions.ts

@@ -0,0 +1,25 @@
+import { Knex } from 'knex';
+
+const getPermission = (subject: string, actions: string[]) => actions.map(action => ({ subject, action }));
+
+export async function up(knex: Knex): Promise<void> {
+  await knex.schema.createTable('permissions', (table) => {
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'));
+    table.string('action').notNullable();
+    table.string('subject').notNullable();
+
+    table.timestamps(true, true);
+  });
+
+  await knex('permissions').insert([
+    ...getPermission('Connection', ['create', 'read', 'delete', 'update']),
+    ...getPermission('Execution', ['read']),
+    ...getPermission('Flow', ['create', 'delete', 'publish', 'read', 'update']),
+    ...getPermission('Role', ['create', 'delete', 'read', 'update']),
+    ...getPermission('User', ['create', 'delete', 'read', 'update']),
+  ]);
+}
+
+export async function down(knex: Knex): Promise<void> {
+  return knex.schema.dropTable('permissions');
+}