Architecting GraphQL apps workshop

Getting started

We will work with your Heroku app, if you haven't created a Heroku app already then you can deploy using:

Add admin secret

1. From the Heroku app dashboard (dashboard.heroku.com/apps/<my-app-name>), navigate to the Settings tab -> Reveal config vars.

2. Add a new config var: HASURA_GRAPHQL_ADMIN_SECRET: adminsecret

For local Docker setup

In case you prefer to work locally with docker containers instead:

Use docker-compose up -d

View your new Hasura GraphQL Engine Console at http://localhost:8080 (admin secret from docker-compose.yaml: adminsecret)

Note: To end a session, use docker-compose down -v

Loading initial data

Via console

• Head to the Data tab and go to the Run SQL window
• Run schema.sql
• Run data.sql

For a Heroku deployment

From the Heroku app dashboard (dashboard.heroku.com/apps/<my-app-name>), navigate to the Settings tab -> Reveal config vars -> DATABASE_URL. Use the following command:

psql <DATABASE_URL> < schema.sql
psql <DATABASE_URL> < data.sql

or, lacking psql, use the following with the heroku CLI: (might need to run heroku login first):

heroku pg:psql -a <my-app-name> < schema.sql
heroku pg:psql -a <my-app-name> < data.sql

For local Docker setup

Use the following command to set up initial tables and data into your postgres container:

psql postgres://postgres:mypassword@localhost:6432/postgres < schema.sql 
psql postgres://postgres:mypassword@localhost:6432/postgres < data.sql 

If you do not have psql available, you can copy the schema.sql and data.sql file to the postgres container and execute the psql command via inside it:

Note: You can find <postgres-container-ID> with docker ps

docker cp schema.sql <postgres-container-ID>:/
docker cp data.sql <postgres-container-ID>:/
docker exec -ti <postgres-container-ID> /bin/bash
psql -U postgres < schema.sql
psql -U postgres < data.sql

Track tables and foreign-key relations

Return to the Hasura GraphQL Engine console and select the Data tab. In the central view, there should be a section "Untracked tables or views" with several tables listed and a "Track All" option available. Select "Track All", and then "Track All" again for untracked foreign-key relations.

Now you're all set! You should see your tables listed in the left-hand panel.

Go to the Graphiql tab and start trying out queries, mutations, and subscriptions.

Dataset

• Users: Users who are browsing and purchasing items
• Products: Inventory of products on sale
• Orders: Order information

Exploring the GraphQL API

• Existing database
• CRUD
• Subscriptions

Authn and Authz

• x-hasura-admin-secret
• Hasura Authz

Model reads

• Define roles on models
• x-hasura-role and x-hasura-user-id
• Authorized models/views/functions

Model writes (Actions)

https://codesandbox.io/s/determined-shockley-4gys1?file=/src/index.js

• Place an order
• Create shipment (SaaS API: https://logistics-api-2.herokuapp.com/v1/graphql)
• Create action relationship (remote join)

To test if action is working:

app.post("/test", (req, res) => {
  return res.json({ order_id: 1 });
});

Remote joins

• Add Remote Schema
• Create remote relationship

Model events

• Sync with analytics db (data event)
• EOD reports (time event)
• Mark delivery complete (time event)

CQRS and 3factor app