Quick Start

Minimal image

The following example demonstrates how to create a minimal image specification using the Image Builder API. This setup leverages the Container Object Storage Interface (COSI) for managing bucket credentials.

Note

You can use any of the object storage providers, that support S3 protocol and has COSI (v1alpha1) driver.

Example of such drivers are:

• Ceph COSI
• Linode COSI Driver

Example Configuration

apiVersion: image-builder.anza-labs.dev/v1alpha1
kind: Image
metadata:
  name: minimal
spec:
  format: 'kernel+initrd'
  configuration: |
    kernel:
      image: linuxkit/kernel:6.6.13
      cmdline: "console=tty0 console=ttyS0 console=ttyAMA0"
    init:
      - linuxkit/init:e120ea2a30d906bd1ee1874973d6e4b1403b5ca3
      - linuxkit/runc:6062483d748609d505f2bcde4e52ee64a3329f5f
      - linuxkit/containerd:39301e7312f13eedf19bd5d5551af7b37001d435
    onboot:
      - name: dhcpcd
        image: linuxkit/dhcpcd:e9e3580f2de00e73e7b316a007186d22fea056ee
        command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
    services:
      - name: getty
        image: linuxkit/getty:5d86a2ce2d890c14ab66b13638dcadf74f29218b
        env:
        - INSECURE=true
  bucketCredentials:
    name: s3-credentials

Applying the Configuration

Save the above configuration into a file named minimal-image.yaml. You can then apply it using kubectl:

kubectl apply -f minimal-image.yaml

Once applied, you can verify the status and access the generated secrets as follows:

$ kubectl get images.image-builder.anza-labs.dev minimal
NAME      READY
minimal   true

To view the created secrets:

$ kubectl get secrets minimal
NAME      TYPE     DATA   AGE
minimal   Opaque   3      3m36s

To retrieve the key and presigned URL from the secret:

$ kubectl get secrets minimal -o=json | jq -r '.data."<Output Name>"' | base64 -d
<Object Key> = <Presigned URL>

You can then use e.g. mc to fetch the objects:

$ mc ls <alias>/<bucket>/default/minimal/kernel-initrd/
[2024-12-30 18:57:13 CET]    42B STANDARD image-cmdline
[2024-12-30 19:00:48 CET]  77MiB STANDARD image-initrd-img
[2024-12-30 19:01:12 CET] 8.7MiB STANDARD image-kernel