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Prisma

This app comes from Prisma's REST API Example and shows how to create a REST API using Express and Prisma Client and deploy it onto Unikraft Cloud. It uses a SQLite database file with some initial dummy data which you can find at ./prisma/store.db. To run it, follow these steps:

  1. Install the kraft CLI tool and a container runtime engine, for example Docker.

  2. Clone the examples repository and cd into the examples/node18-prisma-rest-express/ directory:

Code(bash)
git clone https://github.com/kraftcloud/examples cd examples/node18-prisma-rest-express/

Make sure to log into Unikraft Cloud by setting your token and a metro close to you. This guide uses fra (Frankfurt, ๐Ÿ‡ฉ๐Ÿ‡ช):

Code(bash)
# Set Unikraft Cloud access token export UKC_TOKEN=token # Set metro to Frankfurt, DE export UKC_METRO=fra

When done, invoke the following command to deploy this app on Unikraft Cloud:

Code(bash)
kraft cloud deploy -M 512 -p 443:3000 .

The output shows the instance address and other details:

Code(ansi)
[โ—] Deployed successfully! โ”‚ โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ name: node18-prisma-hdof1 โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ uuid: 066f55cb-bcbd-45e5-9f6b-b3866c3a3a4c โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ state: running โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ url: https://funky-sun-4bf8v7g9.fra.unikraft.app โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ image: node18-prisma@sha256:770d4af1d490daea11171c680eaf99e2a6017a262ba9fbf1ba8d708f5fc32bfe โ”œโ”€โ”€โ”€โ”€โ”€ boot time: 37.94 ms โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ memory: 512 MiB โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€ service: funky-sun-4bf8v7g9 โ”œโ”€โ”€ private fqdn: node18-prisma-hdof1.internal โ”œโ”€โ”€โ”€โ”€ private ip: 172.16.28.2 โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€ args: /usr/bin/node /usr/src/server.js

In this case, the instance name is node18-prisma-hdof1 and the address is https://funky-sun-4bf8v7g9.fra.unikraft.app. They're different for each run.

Use curl to test the REST API, such as the /users endpoint:

Code(bash)
curl https://funky-sun-4bf8v7g9.fra.unikraft.app/users
Code(json)
[{"id":1,"email":"alice@prisma.io","name":"Alice"}, {"id":2,"email":"nilu@prisma.io","name":"Nilu"}, {"id":3,"email":"mahmoud@prisma.io","name":"Mahmoud"}]

You can list information about the instance by running:

Code(bash)
kraft cloud instance list
Code(text)
NAME FQDN STATE CREATED AT IMAGE MEMORY ARGS BOOT TIME node18-prisma-hdof1 funky-sun-4bf8v7g9.fra.unikraft.app running 1 minute ago node18-prisma@sha25... 512 MiB /usr/bin/node /usr/src/server.js 37935us

When done, you can remove the instance:

Code(bash)
kraft cloud instance remove node18-prisma-hdof1

If you would like to test the server locally before deploying to Unikraft Cloud, follow the instructions here.

Using the app

You can access the REST API of the server using the following endpoints:

Endpoints

  • GET /post/:id: Fetch a single post by its id
  • GET /feed?searchString={searchString}&take={take}&skip={skip}&orderBy={orderBy}: Fetch all published posts
    • Query Parameters
      • searchString (optional): This filters posts by title or content
      • take (optional): This specifies how many objects the list should return
      • skip (optional): This specifies how many of the returned objects in the list to skip
      • orderBy (optional): The sort order for posts in either ascending or descending order. The value can either asc or desc
  • GET /user/:id/drafts: Fetch user's drafts by their id
  • GET /users: Fetch all users
  • POST /post: Create a new post
    • Body:
      • title: String (required): The title of the post
      • content: String (optional): The content of the post
      • authorEmail: String (required): The email of the user that creates the post
  • POST /signup: Create a new user
    • Body:
      • email: String (required): The email address of the user
      • name: String (optional): The name of the user
      • postData: PostCreateInput[] (optional): The posts of the user
  • PUT /publish/:id: Toggle the publish value of a post by its id
  • PUT /post/:id/views: Increases the viewCount of a Post by one id
  • DELETE /post/:id: Delete a post by its id

Evolving the app

Evolving the app typically requires two steps:

  1. Migrate your database using Prisma Migrate
  2. Update your app code

For the following example scenario, assume you want to add a "profile" feature to the app where users can create a profile and write a short bio about themselves.

1. Migrate your database using Prisma Migrate

The first step is to add a new table, for example called Profile, to the database. You can do this by adding a new model to your Prisma schema file file and then running a migration afterward:

Code
// ./prisma/schema.prisma model User { id Int @default(autoincrement()) @id name String? email String @unique posts Post[] + profile Profile? } model Post { id Int @id @default(autoincrement()) createdAt DateTime @default(now()) updatedAt DateTime @updatedAt title String content String? published Boolean @default(false) viewCount Int @default(0) author User? @relation(fields: [authorId], references: [id]) authorId Int? } +model Profile { + id Int @default(autoincrement()) @id + bio String? + user User @relation(fields: [userId], references: [id]) + userId Int @unique +}

Once you've updated your data model, you can execute the changes against your database with the following command:

Code
npx prisma migrate dev --name add-profile

This adds another migration to the prisma/migrations directory and creates the new Profile table in the database.

2. Update your app code

You can now use your PrismaClient instance to perform operations against the new Profile table. Those operations can create API endpoints in the REST API.

2.1 Add the app programming interface endpoint to your app

Update your src/index.js file by adding a new endpoint to your API:

Code(js)
app.post('/user/:id/profile', async (req, res) => { const { id } = req.params const { bio } = req.body const profile = await prisma.profile.create({ data: { bio, user: { connect: { id: Number(id) } } } }) res.send(profile) })

2.2 Testing out your new endpoint

Restart your app server and test out your new endpoint.

Create endpoint
  • /user/:id/profile: Create a new profile based on the user id
    • Body:
      • bio: String : The bio of the user

Here are some more sample Prisma Client queries on the new Profile model:

Create a new profile for an existing user
Code(ts)
const profile = await prisma.profile.create({ data: { bio: 'Hello World', user: { connect: { email: 'alice@prisma.io' }, }, }, })
Create a new user with a new profile
Code(ts)
const user = await prisma.user.create({ data: { email: 'john@prisma.io', name: 'John', profile: { create: { bio: 'Hello World', }, }, }, })
Update the profile of an existing user
Code(ts)
const userWithUpdatedProfile = await prisma.user.update({ where: { email: 'alice@prisma.io' }, data: { profile: { update: { bio: 'Hello Friends', }, }, }, })

Switch to another database

If you want to try this example with another database than SQLite, you can adjust the database connection in prisma/schema.prisma by reconfiguring the datasource block.

Learn more about the different connection configurations in the docs.

PostgreSQL

For PostgreSQL, the connection address has the following structure:

Code
datasource db { provider = "postgresql" url = "postgresql://USER:PASSWORD@HOST:PORT/DATABASE?schema=SCHEMA" }

Here is an example connection string with a local PostgreSQL database:

Code
datasource db { provider = "postgresql" url = "postgresql://janedoe:mypassword@localhost:5432/notesapi?schema=public" }

MySQL

For MySQL, the connection address has the following structure:

Code
datasource db { provider = "mysql" url = "mysql://USER:PASSWORD@HOST:PORT/DATABASE" }

Here is an example connection string with a local MySQL database:

Code
datasource db { provider = "mysql" url = "mysql://janedoe:mypassword@localhost:3306/notesapi" }

Microsoft structured query language server database

Here is an example connection string with a local Microsoft SQL Server database:

Code
datasource db { provider = "sqlserver" url = "sqlserver://localhost:1433;initial catalog=sample;user=sa;password=mypassword;" }

MongoDB

Here is an example connection string with a local MongoDB database:

Code
datasource db { provider = "mongodb" url = "mongodb://USERNAME:PASSWORD@HOST/DATABASE?authSource=admin&retryWrites=true&w=majority" }

Learn more

Use the --help option for detailed information on using Unikraft Cloud:

Code(bash)
kraft cloud --help

Or visit the CLI Reference.

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