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Unikraft Cloud

Deploy a Dragonfly DB

This guides shows you how to deploy Dragonfly, a simple, performant, and cost-efficient in-memory data store.

To run it example, follow these steps:

  1. Install the kraft CLI tool and a container runtime engine, e.g. Docker.

  2. Clone the examples repository and cd into the examples/dragonflydb/ directory:

Terminal window
git clone https://github.com/kraftcloud/examples
cd examples/dragonflydb/

Make sure to log into Unikraft Cloud by setting your token and a metro close to you. We use fra0 (Frankfurt, 🇩🇪) in this guide:

Terminal window
# Set Unikraft Cloud access token
export UKC_TOKEN=token
# Set metro to Frankfurt, DE
export UKC_METRO=fra0

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

Terminal window
kraft cloud deploy -p 443:6379 -M 512 .

The output shows the instance URL and other details:

Terminal window
[●] Deployed successfully!
 │
 ├────────── name: dragonflydb-10zgk
 ├────────── uuid: 6282ef0c-2161-494c-a3f3-2d16055096c2
 ├───────── state: running
 ├─────────── url: https://dry-moon-x6bgl6c0.fra0.kraft.host
 ├───────── image: dragonflydb@sha256:21e6d3ff1f86292e14266bcf5c6e73d3b7a86a0ec4102c66a0961373af743f19
 ├───── boot time: 28.74 ms
 ├──────── memory: 512 MiB
 ├─────── service: dry-moon-x6bgl6c0
 ├── private fqdn: dragonflydb-10zgk.internal
 ├──── private ip: 172.16.6.5
 └────────── args: /usr/bin/dragonfly --maxmemory 256MiB

In this case, the instance name is dragonflydb-10zgk and the URL is https://dry-moon-x6bgl6c0.fra0.kraft.host. They are different for each run.

Use curl to query the Unikraft Cloud instance of Drangonfly.

Terminal window
curl https://dry-moon-x6bgl6c0.fra0.kraft.host
<!DOCTYPE html>
<html><head>
<meta http-equiv='Content-Type' content='text/html; charset=UTF-8'/>
    <link href='https://fonts.googleapis.com/css?family=Roboto:400,300' rel='stylesheet'
     type='text/css'>
    <link rel='stylesheet' href='http://static.dragonflydb.io/data-plane/status_page.css'>
    <script type="text/javascript" src="http://static.dragonflydb.io/data-plane/status_page.js"></script>
</head>
<body>
<div><img src='http://static.dragonflydb.io/data-plane/logo.png' width="160"/></div>
<div class='left_panel'></div>
<div class='styled_border'>
<div>Status:<span class='key_text'>OK</span></div>
<div>Started on:<span class='key_text'>1970-01-01T00:00:00</span></div>
<div>Uptime:<span class='key_text'>474611:3:38</span></div>
<div>Render Latency:<span class='key_text'>110 us</span></div>
</div>
</body>
<script>
var json_text1 = {"engine": { "keys": 0,"obj_mem_usage": 0,"table_load_factor": 0 },
"current-time": 1708599818};
document.querySelector('.left_panel').innerHTML = JsonToHTML(json_text1);
</script>
</html>

At any point in time, you can list information about the instance:

Terminal window
kraft cloud instance list
NAME               FQDN                              STATE    CREATED AT    IMAGE                            MEMORY   ARGS                                     BOOT TIME
dragonflydb-10zgk  dry-moon-x6bgl6c0.fra0.kraft....  running  1 minute ago  dragonflydb@sha256:21e6d3...     512 MiB  /usr/bin/dragonfly --maxmemor...         28740us

When done, you can remove the instance:

Terminal window
kraft cloud instance remove dragonflydb-10zgk

Customize your Application

To customize the application, update the files in the repository, listed below:

  • Kraftfile: the Unikraft Cloud specification, including command-line arguments
  • Dockerfile: In case you need to add files to your instance’s rootfs
spec: v0.6


runtime: dragonfly:latest


rootfs: ./Dockerfile


cmd: ["/usr/bin/dragonfly", "--maxmemory", "256MiB"]

Learn More

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

Terminal window
kraft cloud --help

Or visit the CLI Reference.