Postgres

This library allows using postgres with Wing.

Prerequisites

• winglang
• Neon free-tier account (for deploying on AWS)

Installation

Use npm to install this library:

npm i @winglibs/postgres

Bring it

bring cloud;
bring postgres;

let db = new postgres.Database(
  name: "mydb",
  pgVersion: 15,
);

let api = new cloud.Api();

api.get("/users", inflight (req) => {
  let users = db.query("select * from users");
  return {
    status: 200,
    body: Json.stringify(users),
  };
});

You can find connection information in db.connection:

• host - the host to connect to
• port - the external port to use (a token that will resolve at runtime)
• user - user name
• password - password
• database - the database name
• ssl - use SSL or not

sim

When executed in the Wing Simulator, postgres is run within a local Docker container.

Connecting to Postgres from sim.Container

If you are connecting from a sim.Container, you should use host.docker.internal as the host in order to be able to access the host network:

Example:

new sim.Container(
  // ...
  env: {
    DB_HOST: "host.docker.internal",
    DB_PORT: db.connection.port
  }
)

Reference Existing Postgres Database

If you want to import a reference to an existing postgres database, you can use the DatabaseRef class:

bring postgres;

let db = new postgres.DatabaseRef() as "somedatabase";


new cloud.Function(inflight() => {
  let users = db.query("select * from users");
});

This will automatically create a secret resource that is required for the database connection. To seed this secret, use the secrets subcommand:

❯ wing secrets main.w
1 secret(s) found

? Enter the secret value for connectionString_somedatabase: [input is hidden] 

When referencing an existing database for the tf-aws target you will also need to specify VPC information in your wing.toml file (unless your database is publicly accessible). Or you will see an warning like this:

WARNING: Unless your database is accessible from the public internet, you must provide vpc info under `tf-aws` in your wing.toml file
For more info see: https://www.winglang.io/docs/platforms/tf-aws#parameters

tf-aws

On the tf-aws target, the postgres database can be created and hosted by either AWS RDS or Neon. To configure which one to use, simply specify the parameter postgresEngine in your wing.toml file:

postgresEngine = "rds" # or "neon"

Neon Setup

Neon has a free tier that can be used for personal projects and prototyping.

Database credentials are securely stored on AWS Secrets Manager (via cloud.Secret).

When you deploy Terraform that uses the Database class, you will need to have the NEON_API_KEY environment variable set with an API key.

Roadmap

• Support tf-aws platform using Neon
• Support sim platform
• Make all Neon databases share a Neon project to stay within the free tier
• Reuse postgres client across multiple queries by requiring users to call connect() / end() methods
• Initialize secret value through cloud.Secret APIs - https://github.com/winglang/wing/issues/2726
• Support parameterized queries for preventing SQL injection
• Customize type parser for most popular postgres types / conversions to Wing types
• Have query() return both rows and a list of field names
• More unit tests and examples

License

Licensed under the MIT License.

API Reference

Table of Contents

• Classes
  • Database
  • DatabaseRef
• Interfaces
  • IDatabase
• Structs
  • AwsParameters
  • ConnectionOptions
  • DatabaseProps

Database (preflight class)

No description

Constructor

new(props: DatabaseProps): Database

Properties

Name	Type	Description
connection	ConnectionOptions	No description

Methods

Signature	Description
inflight connectionOptions(): ConnectionOptions	No description
inflight query(query: str): Array<Map>	No description

DatabaseRef (preflight class)

No description

Constructor

new(): DatabaseRef

Properties

No properties

Methods

Signature	Description
inflight query(query: str): Array<Map>	No description

IDatabase (interface)

No description

Properties

No properties

Methods

Signature	Description
inflight connectionOptions(): ConnectionOptions?	No description
inflight query(query: str): Array<Map>	No description

AwsParameters (struct)

No description

Properties

Name	Type	Description
postgresEngine	str?	No description

ConnectionOptions (struct)

No description

Properties

Name	Type	Description
database	str	No description
host	str	No description
password	str	No description
port	str	No description
ssl	bool	No description
user	str	No description

DatabaseProps (struct)

No description

Properties

Name	Type	Description
name	str	No description
pgVersion	num?	No description