Valkey#

Valkey is a fork of Redis v7.2.4 with additional features and improvements. It is backed by the Linux Foundation, ensuring it will remain open source forever.

VaporValkey is an integration between Vapor and valkey-swift, which is the underlying driver that communicates with both Valkey and Redis (up to v7.2.4).

Package#

The first step to using VaporValkey is adding it and valkey-swift as dependencies to your project in your Swift package manifest.

dependencies: [
    // ...
    .package(url: "https://github.com/vapor/valkey.git", from: "1.2.0"),
    .package(url: "https://github.com/valkey-io/valkey-swift.git", from: "1.0.0"),
],
targets: [
    .target(name: "App", dependencies: [
        // ...
        .product(name: "VaporValkey", package: "VaporValkey"),
        .product(name: "Valkey", package: "valkey-swift"),
    ])
]

Configure#

ValkeyClient and ValkeyClusterClient use a connection pool, and there are several options to configure individual connections as well as the pools themselves.

The bare minimum required for configuring a Valkey client is to provide a URL to connect to:

import Valkey
import Vapor
import VaporValkey

let app = Application()

app.valkey = ValkeyClient(
    .hostname("localhost"),
    eventLoopGroup: app.eventLoopGroup,
    logger: app.logger
)

When assigning the Application‘s valkey property, the Application will take ownership of the Valkey client’s lifecycle. Specifically, this assignment operation will automatically run the client and its connection pool, and they will be automatically cancelled when the Application is shut down.

The Application’s valkey property can accept either ValkeyClient or ValkeyClusterClient. For more information about these clients and their configuration, see the valkey-swift documentation.

Sending a Command#

You can send commands using the .valkey property on any Application or Request instance, which will give you access to a ValkeyClientProtocol.

Any ValkeyClientProtocol has several extensions for all of the various Valkey commands.

import Valkey
import Vapor
import VaporValkey

try await app.valkey.set("mykey", value: "myvalue")

let value: RESPBulkString? = try await app.valkey.get("my_key")
if let value {
    print(String(value))
}

Pub/Sub Mode#

Valkey and Redis support the ability to enter a “Pub/Sub” mode where a connection can listen to specific “channels” and run specific closures when the subscribed channels publish a “message” (some data value).

There is a defined lifecycle to a subscription:

1. subscribe: invoked once when the subscription first starts

2. message: invoked 0+ times as messages are published to the subscribed channels

3. unsubscribe: invoked once when the subscription ends, either by request or the connection being lost

Use subscribe(to:process:) to subscribe to one or more channels and receive every message published to those channels as an AsyncSequence. When you exit the closure, the Valkey client sends the relevant UNSUBSCRIBE messages.

import Valkey
import Vapor
import VaporValkey

try await app.valkey.publish(channel: "channel", message: "Hello, World!")

try await app.valkey.subscribe(to: ["channel"]) { subscription in
    for try await item in subscription {
        print(item.channel)
        print(String(item.message))
    }
}

See the documentation of valkey-swift on pub/sub to learn more about all available subscription features and usage patterns.