airshipctl/tools/airship-in-a-pod

Airship in a Pod

Airship in a pod is a Kubernetes pod definition which describes all of the components required to deploy a fully functioning Airship 2 deployment. The pod consists of the following "Task" containers:

• artifact-setup: This container collects the airshipctl binary repo, builds the airshipctl binary (and associated kustomize plugins), and makes them available to the other containers
• infra-builder: This container creates the various virtual networks and machines required for an Airship deployment
• runner: The runner container is the "meat" of the pod, and executes the deployment. It sets up a customized airshipctl config file, then uses airshipctl to pull the specified manifests and execute the deployment

The pod also contains the following "Support" containers:

• libvirt: This provides virtualisation
• sushy-tools: This is used for its BMC emulator
• docker-in-docker: This is used for nesting containers
• nginx: This is used for image hosting
• status-checker: This container is used to track the completion status of the task containers.

Deployment Options

1. Deploy on Azure (Quick Start)
2. Deploy using Minikube on Linux

Azure Kubernetes Service (AKS) Quick Start

Note: This section provides a means of very quickly getting up and running with AIAP, but requires access to Azure. If you would like to deploy to a native Linux environment, please refer to the Minikube Installation.

Upon logging into and authenticating an Azure account (via az login), Airship-in-a-Pod can be easily run within AKS by running the script:

tools/airship-in-a-pod/scripts/aiap-in-aks.sh

Environment variables can be supplied to override default, such as:

• AIAP_POD: the kustomization to use for the AIAP Pod definition
• CLEANUP_GROUP: whether to delete the resource group created for AIAP. Defaults to false.

Please consult the script for the full list of overrideable variables.

Minikube Installation

This sections provides instructions for deploying AIAP to a single-node minikube.

Prerequisites

• Nested Virtualisation: If deploying on a VM, ensure that nested virtualisation is enabled.
• Environment variable setup: If you are within a proxy environment, ensure that the following environment variables are defined, and NO_PROXY has the IP address which minikube uses. Check the minikube documentation for retrieving the minikube ip.

export USE_PROXY=true
export HTTP_PROXY=http://username:password@host:port
export HTTPS_PROXY=http://username:password@host:port
export NO_PROXY="localhost,127.0.0.1,10.23.0.0/16,10.96.0.0/12,10.1.1.44"
export http_proxy="$HTTP_PROXY"
export https_proxy="$HTTPS_PROXY"
export no_proxy="$NO_PROXY"

To start minikube

Within the environment, with appropriate env variables set, run the following command.

sudo -E minikube start --driver=none

Refer to the minikube documentation for more details.

Deploy the Pod

Since Airship in a Pod is just a pod definition, deploying and using it is as simple as deploying and using any other Kubernetes pod with kubectl apply -f. The base pod definition can be found here and deploys using the current master airshipctl binary and current master test site.

Pod configuration

Further configuration can be applied to the pod definition via kustomize. Options that can be configured can be found in the airshipctl example. You may choose to either modify one of the examples or create your own.

Once you've created the desired configuration, the kustomized pod can be deployed with the following:

kustomize build ${PATH_TO_KUSTOMIZATION} | kubectl apply -f -

Finishing a Deployment

A deployment of Airship-in-a-pod is denoted by one of two states:

1. The runner container reaches the end of its execution successfully
2. An error occurs in any of the containers

The statuses for the task containers is aggregated in the status-checker container, which provides a status report every 5 seconds. The status report has the following structure:

artifact-setup: <$STATUS> infra-builder: <$STATUS> runner: <$STATUS>

In the above, $STATUS can be any of RUNNING, SUCCESS, FAILED, or UNKNOWN. The last line of the status-checker's logs will always contain the most recent status report. This status report can be used to determine the overall health of the deployment, as in the following:

# Check if AIAP has finished successfully
test $(kubectl logs airship-in-a-pod -c status-checker --tail 1 | grep -o "SUCCESS" | wc -l) = 3

# Check if AIAP has failed
kubectl logs airship-in-a-pod -c status-checker --tail 1 | grep -q "FAILED"

Interacting with the Pod

For a quick rundown of what a particular container is doing, simply check the logs for that container.

# $CONTAINER is one of [runner infra-builder artifact-setup libvirt sushy dind nginx]
kubectl logs airship-in-a-pod -c $CONTAINER

For a deeper dive, consider execing into one of the containers.

# $CONTAINER is one of [runner infra-builder artifact-setup libvirt sushy dind nginx]
kubectl exec -it airship-in-a-pod -c $CONTAINER -- bash

Interacting with the Nodes

If you would like to interact with the nodes used in the deployment, you should first prevent the runner container from exiting (check the examples/airshipctl replacements for the option to do this). While the runner container is alive, exec into it using the above command. The kubectl tool can then be used to interact with a cluster. Choose a context from kubectl config get-contexts and switch to it via kubectl config use-context ${MY_CONTEXT}.

Output

Airship-in-a-pod produces the following outputs:

• The airshipctl repo, manifest repo, and airshipctl binary used with the deployment.
• A tarball containing the generated ephemeral ISO, as well as the configuration used during generation.

These artifacts are placed at ARTIFACTS_DIR (defaults to /opt/aiap-files/artifacts).

Caching

#TODO: Need to review this.

As it can be cumbersome and time-consuming to build and rebuild binaries and images, some options are made available for caching. A developer may re-use artifacts from previous runs (or provide their own) by placing them in CACHE_DIR (defaults to /opt/aiap-files/cache). Special care is needed for the caching:

• If using a cached airshipctl, the airshipctl binary must be stored in the $CACHE_DIR/airshipctl/bin/ directory, and the developer must have set USE_CACHED_AIRSHIPCTL to true.
• If using a cached ephemeral iso, the iso must first be contained in a tarball named iso.tar.gz, must be stored in the $CACHE_DIR/ directory, and the developer must have set USE_CACHED_ISO to true.