Create a service

To create a service, you have to:

1. Add the new service in packages/services/list.ts with the corresponding new unique port and name.

2. Create a new package in the directory packages/services/.

3. The new service's package.json should at least have this defined:

   {
     "name": "service-NEW_SERVICE_NAME",
     "version": "0.0.1",
     "private": true,
     "scripts": {
       "dev": "bob-tsm --node-env=dev --watch=src src/index.ts",
       "start": "bob-tsm src/index.ts"
     },
     "dependencies": {
       "api-base": "workspace:^0.0.1",
       "db": "workspace:^0.0.1"
     }
   }

   This will give the new service access to the db package, which has the database connection and related code, and the api-base package, which has useful shared code between services.

4. The new service needs a tsconfig.json alongside the just created package.json. It should be defined like this:

This configuration extends the main typescript configuration but isolates the service types

{
  "extends": "../../../tsconfig.json",
  "include": ["**/*"],
  "exclude": ["**/node_modules"]
}

5. The new service's "src/index.ts" file should look something like this:

   import { baseServicesList, logger, pubSub, smartListen } from "api-base";
   import Fastify from "fastify";
   import { buildApp } from "./ez";
   
   // This creates the new web server
   const app = Fastify({
     logger,
     pluginTimeout: 30000,
   });
   
   // This builds the GraphQL EZ API
   const ezApp = buildApp({
     async prepare() {
       // This will add the new expected gql api modules
       await import("./modules/index");
     },
   });
   
   app.register(ezApp.fastifyPlugin);
   
   app.ready(async (err) => {
     if (err) {
       console.error(err);
       process.exit(1);
     }
   
     // This will listen on the expected port, considering development mode and environment variables.
     await smartListen(app, baseServicesList.NEW_SERVICE_NAME);
   
     // This will notify the gateway to re-introspect all the services, and detect possible changes
     pubSub.publish("updateGateway", "NEW_SERVICE_NAME");
   });

6. The new service's "src/ez.ts" file should look something like this:

   import { CreateApp } from "@graphql-ez/fastify";
   
   import { ezServicePreset } from "api-base";
   
   // This created the new GraphQL EZ instance, re-using a service preset with tools like GraphQL Codegen, GraphQL Altair and GraphQL Voyager
   export const { buildApp, gql, registerModule } = CreateApp({
     ez: {
       preset: ezServicePreset,
     },
   });
   
   export * from "api-base";

7. A new service module, let's call it "src/modules/foo.ts", should start looking like this:

   import { gql, registerModule } from "../ez";
   
   export const fooModule = registerModule(
     // This defines the types
     gql`
       extend type Query {
         foo: String!
       }
     `,
     {
       id: "Foo",
       dirname: import.meta.url,
       // This defines the resolvers associated with the defined types
       resolvers: {
         Query: {
           foo() {
             return "Foo!";
           },
         },
       },
     }
   );

8. And a new file "src/modules/index.ts" should start looking like this:

   export * from "./foo";

9. Update the root docker-compose.yaml to include the new service; you can follow the format of the existing services.