(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/gen-server/migration/1561589211752-Aliases.ts

@@ -0,0 +1,67 @@
+import {MigrationInterface, QueryRunner, Table, TableColumn, TableIndex} from 'typeorm';
+import {datetime, now} from 'app/gen-server/sqlUtils';
+
+export class Aliases1561589211752 implements MigrationInterface {
+
+  public async up(queryRunner: QueryRunner): Promise<any> {
+    const dbType = queryRunner.connection.driver.options.type;
+
+    // Make a table for document aliases.
+    await queryRunner.createTable(new Table({
+      name: 'aliases',
+      columns: [
+        {
+          name: 'url_id',
+          type: 'varchar',
+          isPrimary: true
+        },
+        {
+          name: 'org_id',
+          type: 'integer',
+          isPrimary: true
+        },
+        {
+          name: 'doc_id',
+          type: 'varchar',
+          isNullable: true   // nullable in case in future we make aliases for other resources
+        },
+        {
+          name: "created_at",
+          type: datetime(dbType),
+          default: now(dbType)
+        }
+      ],
+      foreignKeys: [
+        {
+          columnNames: ['doc_id'],
+          referencedColumnNames: ['id'],
+          referencedTableName: 'docs',
+          onDelete: 'CASCADE'  // delete alias if doc goes away
+        },
+        {
+          columnNames: ['org_id'],
+          referencedColumnNames: ['id'],
+          referencedTableName: 'orgs'
+          // no CASCADE set - let deletions be triggered via docs
+        }
+      ]
+    }));
+
+    // Add preferred alias to docs.  Not quite a foreign key (we'd need org as well)
+    await queryRunner.addColumn('docs', new TableColumn({
+        name: 'url_id',
+        type: 'varchar',
+        isNullable: true
+    }));
+    await queryRunner.createIndex("docs", new TableIndex({
+      name: "docs__url_id",
+      columnNames: ["url_id"]
+    }));
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<any> {
+    await queryRunner.dropIndex('docs', 'docs__url_id');
+    await queryRunner.dropColumn('docs', 'url_id');
+    await queryRunner.dropTable('aliases');
+  }
+}