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Example apps

Prisma HTTP Server

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 migration data.

To run this example, follow these steps:

1. Install the unikraft CLI. You need a BuildKit builder. The easiest way to get one is via Docker. Alternatively, you can also directly set up and use BuildKit, see the quick start.

2. Clone the examples repository and cd into the examples/httpserver-prisma-expressjs4.19-node18/ directory:

   Code
   git clone https://github.com/unikraft-cloud/examples
   cd examples/httpserver-prisma-expressjs4.19-node18/

Make sure to log into Unikraft Cloud and pick a metro close to you. This guide uses fra (Frankfurt, 🇩🇪):

Code
unikraft login

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

Code
unikraft build . --output <my-org>/httpserver-prisma-expressjs419-node18:latest
unikraft run --metro fra \
  -m 512M \
  -p 443:3000/tls+http \
  --scale-to-zero policy=on,cooldown-time=1000 \
  --image <my-org>/httpserver-prisma-expressjs419-node18:latest

The output shows the instance address and other details:

Code
metro:        fra
name:         httpserver-prisma-expressjs419-node18-hdof1
uuid:         066f55cb-bcbd-45e5-9f6b-b3866c3a3a4c
state:        starting
image:        <my-org>/httpserver-prisma-expressjs419-node18
resources:
  memory:     512MiB
  vcpus:      1
service:
  uuid:       b7da8a3b-ca4d-979a-3ae9-9634bca98008
  name:       funky-sun-4bf8v7g9
  domains:
  - fqdn:     funky-sun-4bf8v7g9.fra.unikraft.app
networks:
- uuid:       63d977e8-548c-f0af-cc97-39856660f612
  private-ip: 10.0.28.2
  mac:        12:b0:43:fb:5c:30
timestamps:
  created:    just now

In this case, the instance name is httpserver-prisma-expressjs419-node18-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
curl https://funky-sun-4bf8v7g9.fra.unikraft.app/users

Code
[{"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
unikraft instances list

Code
METRO  NAME                                         STATE    IMAGE                                           ARGS  MEMORY  VCPUS  FQDN                                 CREATED
fra    httpserver-prisma-expressjs419-node18-hdof1  running  <my-org>/httpserver-prisma-expressjs419-node18        512MiB  1      funky-sun-4bf8v7g9.fra.unikraft.app  2 minutes ago

When done, you can remove the instance:

Code
unikraft instances delete httpserver-prisma-expressjs419-node18-hdof1

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
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
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
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
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
unikraft --help

Or visit the CLI Reference.