airshipctl/tools/airship-in-a-pod/README.md
Fletcher, Stacey (sf5715) a423607000 Airship in a Pod
Introduces Airship in pod. This includes:
* A base image which sets up common requirements
* An image for the libvirt service
* An image for building a specified instance of airshipctl
* An image for initializing the various libvirt infrastructure required
  for a deployment
* An image which runs the deployment scripts

Closes: #313

Change-Id: Ib1114350190b0fe0c0761ff67b38b3eca783161a
2021-02-22 19:55:44 -06:00

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# 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:
* `airshipctl-builder`: This container builds the airshipctl binary and makes it
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
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
## Prerequisites
In order to deploy Airship in a Pod for development, you must first have a
working Kubernetes cluster. This guide assumes that a developer will deploy
using [minikube](https://minikube.sigs.k8s.io/docs/start/):
```
sudo -E minikube start --driver=none
```
## Usage
Since Airship in a Pod is just a pod definition, deploying and using it is as
simple as deploying and using any Kubernetes pod.
#### Deploy the Pod
```
kubectl apply -f airship-in-a-pod.yaml
```
#### View Pod Logs
```
kubectl logs airship-in-a-pod -c $CONTAINER
```
#### Interact with the Pod
```
kubectl exec -it airship-in-a-pod -c $CONTAINER -- bash
```
where `$CONTAINER` is one of the containers listed above.
### Output
Airship-in-a-pod produces the following outputs:
* The airshipctl repo and associated 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-artifacts`).
### Caching
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-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`.