GCP Using Konvoy Image Builder

Konvoy Image Builder (KIB) is a complete solution for building Cluster API compliant images.

This procedure describes how to use the Konvoy Image Builder (KIB) to create a Cluster API compliant GCP image. GCP images contain configuration information and software to create a specific, pre-configured, operating environment. For example, you can create a GCP image of your current computer system settings and software. The GCP image can then be replicated and distributed, creating your computer system for other users. KIB uses variable overrides to specify base image and container images to use in your new GCP image.

Google Cloud Platform does not publish images. You must first build the image using Konvoy Image Builder. Explore the Customize your Image topic for more options. For more information regarding using the image in creating clusters, refer to the GCP Infrastructure section of the documentation.

DKP Prerequisites

Before you begin, you must:

Download the KIB bundle for your version of DKP.
Check the Supported Infrastructure Operating Systems
Check the Supported Kubernetes Version for your Provider.
Create a working Docker or other registry setup.
On Debian-based Linux distributions, install a version of the cri-tools package known to be compatible with both the Kubernetes and container runtime versions.
Verify that your Google Cloud project does not have the Enable OS Login feature enabled. See below for more information:

The Enable OS Login feature is sometimes enabled by default in GCP projects. If the OS login feature is enabled, KIB will not be able to ssh to the VM instances it creates and will not be able to successfully create an image.

To check if it is enabled, use the commands on this page https://cloud.google.com/compute/docs/metadata/setting-custom-metadata#console_2 to inspect the metadata configured in in your project. If you find the the enable-oslogin flag set to TRUE, you must remove (or set it to FALSE) to successfully use KIB.

GCP Prerequisite Roles

If you are creating your image on either a non-GCP instance or one that does not have the required roles, you must either:

Create a GCP service account.
If you have already created a service account, retrieve the credentials for an existing service account.

Export the static credentials that will be used to create the cluster:

CODE

export GCP_B64ENCODED_CREDENTIALS=$(base64 < "${GOOGLE_APPLICATION_CREDENTIALS}" | tr -d '\n')

Make sure to rotate static credentials for increased security.

Build the GCP image

Run the konvoy-image command to build and validate the image:

CODE

./konvoy-image build gcp --project-id ${GCP_PROJECT} --network ${NETWORK_NAME} images/gcp/ubuntu-2004.yaml

KIB will run and print out the name of the created image, you will use this name when creating a Kubernetes cluster. See sample output below:

CODE

...
==> ubuntu-2004-focal-v20220419: Deleting instance...
    ubuntu-2004-focal-v20220419: Instance has been deleted!
==> ubuntu-2004-focal-v20220419: Creating image...
==> ubuntu-2004-focal-v20220419: Deleting disk...
    ubuntu-2004-focal-v20220419: Disk has been deleted!
==> ubuntu-2004-focal-v20220419: Running post-processor: manifest
Build 'ubuntu-2004-focal-v20220419' finished after 7 minutes 46 seconds.

==> Wait completed after 7 minutes 46 seconds

==> Builds finished. The artifacts of successful builds are:
--> ubuntu-2004-focal-v20220419: A disk image was created: konvoy-ubuntu-2004-1-23-7-1658523168
--> ubuntu-2004-focal-v20220419: A disk image was created: konvoy-ubuntu-2004-1-23-7-1658523168

Ensure you have named the correct YAML file for your OS in the konvoy-image build command.

To find a list of images you have created in your account, run the following command:
CODE
```
gcloud compute images list --no-standard-images
```

Create a Network (optional)

Building an image requires a Network with firewall rules that allow SSH access to the VM instance.

Set your GCP Project ID for your gcp account unless already set previously:
CODE
```
export GCP_PROJECT=<your GCP project ID>
```

Run the following to create a new network:

CODE

export NETWORK_NAME=kib-ssh-network
gcloud compute networks create "${NETWORK_NAME}" --project="${GCP_PROJECT}" --subnet-mode=auto --mtu=1460 --bgp-routing-mode=regional

Create the firewall rule to allow Ingress access on port 22:

CODE

gcloud compute firewall-rules create "${NETWORK_NAME}-allow-ssh" --project="${GCP_PROJECT}" --network="projects/${GCP_PROJECT}/global/networks/${NETWORK_NAME}" --description="Allows TCP connections from any source to any instance on the network using port 22." --direction=INGRESS --priority=65534 --source-ranges=0.0.0.0/0 --action=ALLOW --rules=tcp:22

With your KIB image now created, you can now move on to create your cluster and set up your Cluster API (CAPI) controllers.

Konvoy Image Builder has a more detailed section in the documentation if you need to refer there for compatible versions with DKP and other specific information.

Next Topic

GCP Cluster Creation Customization Choices