103 lines
3.2 KiB
Markdown
103 lines
3.2 KiB
Markdown
# Openstack Bootstrap Container
|
|
|
|
This project contains the Go application as well as the shell scripts and configuration files for
|
|
implementing the Openstack Bootstrap container.
|
|
|
|
The Openstack Bootstrap container is responsible to create or delete a Kubernetes (K8S) cluster on
|
|
Openstack. The K8S cluster is created using `kubeadm`.
|
|
|
|
## Go Application
|
|
|
|
The Go application is the container orchestrator that is responsible for translating commands
|
|
into actions: create, delete, help.
|
|
|
|
The Go application reads the Ephemeral cluster configuration file (e.g., openstack-config.yaml) and
|
|
converts the attributes into environment variables. These environment variables are used by the
|
|
shell scripts to create or delete the K8S cluster.
|
|
|
|
To build this Go application, execute the following commands:
|
|
|
|
```bash
|
|
go install .
|
|
go build -o capo-ephemeral
|
|
```
|
|
|
|
## Shell Scripts
|
|
|
|
The shell scripts make use of openstack cli commands to create and delete K8S cluster.
|
|
The other alternative that was considered was to use magnum container orchestration APIs.
|
|
In order to keep things generic, openstack cli command was chosen to create and delete the K8S
|
|
cluster.
|
|
|
|
### Create K8S Cluster script
|
|
|
|
The **create-k8s-cluster.sh** script creates a K8S cluster using the information provided in
|
|
the Ephemeral cluster configuration file. It passes `user-data.sh` script in the
|
|
`openstack server create` command to execute series of steps to initiate creation of the K8S
|
|
cluster at boot time. Once the cluster is created, its **kubeconfig** file is copied to the
|
|
container's volume mount, "sharing" it with the host.
|
|
|
|
### Delete K8S Cluster script
|
|
|
|
The **delete-k8s-cluster.sh** script deletes the underlying VM and the K8S cluster using the
|
|
information provided in the Ephemeral cluster configuration file.
|
|
|
|
## Dockerfile
|
|
|
|
The **Dockerfile** is used to build the Openstack Bootstrap container image.
|
|
Execute the following command to build the Bootstrap container image:
|
|
|
|
```bash
|
|
make docker
|
|
```
|
|
|
|
## Pre-requisite
|
|
|
|
- [Devstack](https://docs.openstack.org/devstack/latest/guides/devstack-with-lbaas-v2.html)
|
|
is installed.
|
|
- The most recent version of the *64-bit amd64-arch QCOW2* image for *Ubuntu 18.04* is used for
|
|
creating the ephemeral cluster.
|
|
The image is available
|
|
[here](https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64.img) for
|
|
download and should be available in the devstack environment.
|
|
|
|
- `~/.airship/` directory on host machine contains `clouds.yaml` and `openstack-config.yaml` files.
|
|
- airship configuration file is updated with `ephemeral` cluster configuration information.
|
|
|
|
## Appendix
|
|
|
|
### Required Configuration
|
|
|
|
#### Ephemeral Cluster Configuration
|
|
|
|
```bash
|
|
$ cat openstack-config.yaml
|
|
apiVersion: v1
|
|
kind: OpenstackCloudConfig
|
|
metadata:
|
|
name: capi-openstack
|
|
credentials:
|
|
credential: clouds.yaml
|
|
cloudName: devstack
|
|
spec:
|
|
cluster:
|
|
machineSize: ds4G
|
|
kubeconfig: capo.kubeconfig
|
|
securityGroup: bootstrap-sec-grp
|
|
```
|
|
|
|
#### Airship Configuration
|
|
|
|
```bash
|
|
$ cat ~/.airship/config
|
|
apiVersion: airshipit.org/v1alpha1
|
|
bootstrapInfo:
|
|
ephemeral:
|
|
container:
|
|
image: quay.io/airshipit/capo-bootstrap:latest
|
|
name: capo-bootstrap
|
|
volume: /home/stack/.airship:/kube
|
|
ephemeralCluster:
|
|
config: openstack-config.yaml
|
|
```
|