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Example apps

Debian SSH server

This guide explains how to create and deploy a Debian app with SSH enabled. 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/debian-ssh directory:

   Code
   git clone https://github.com/unikraft-cloud/examples
   cd examples/debian-ssh/

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>/debian-ssh:latest
unikraft run --metro fra \
  -m 1G \
  -p 2222:2222/tls \
  --scale-to-zero policy=off \
  -e PUBKEY="...." \
  --image <my-org>/debian-ssh:latest

The output shows the instance address and other details:

Code
metro:        fra
name:         debian-ssh-2uwg5
uuid:         b3d158c5-fb52-4685-a76b-2497973308dc
state:        starting
image:        <my-org>/debian-ssh
resources:
  memory:     1024MiB
  vcpus:      1
service:
  uuid:       5771bead-c045-52fa-1f89-5bc4f1cf3c38
  name:       nameless-cherry-sw2e9ul2
  domains:
  - fqdn:     nameless-cherry-sw2e9ul2.fra.unikraft.app
networks:
- uuid:       9d76ad3f-2149-f0af-d77f-76daba253d33
  private-ip: 10.0.0.109
  mac:        12:b0:1d:bd:54:f6
timestamps:
  created:    just now

In this case, the instance name is debian-ssh-2uwg5 and the address is nameless-cherry-sw2e9ul2.fra.unikraft.app. They're different for each run.

You need to set up a tunnel that handles the TLS connection to the Unikraft Cloud instance. This way, you have a non-TLS port that your SSH client can connect to:

Code
socat TCP-LISTEN:2222,reuseaddr,fork OPENSSL:nameless-cherry-sw2e9ul2.fra.unikraft.app:2222,verify=0

Then connect to the instance via SSH using:

Code
ssh -l root localhost -p 2222

You might see warnings like REMOTE HOST IDENTIFICATION HAS CHANGED. This is normal if you have set up tunnels to connect with SSH on localhost, so don't worry.

You can list information about the instance by running:

Code
unikraft instances list

Code
METRO  NAME              STATE    IMAGE                ARGS  MEMORY  VCPUS  FQDN                                    CREATED
fra    debian-ssh-2uwg5  running  <my-org>/debian-ssh        1.0GiB  1      nameless-cherry-sw2e9ul2.fra.unikraft…  2 minutes ago

When done, you can remove the instance:

Code
unikraft instances delete debian-ssh-2uwg5

Learn more

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

Code
unikraft --help

Or visit the CLI Reference.