Introduction
At their 2018 annual Re:Invent conference, AWS announced an exciting new product called “Firecracker” that is quickly setting the cloud-native ecosystem on fire. Firecracker is a Virtual Machine Manager (VMM) exclusively designed for running transient and short-lived processes. In other words, it is optimized for running functions and serverless workloads that require faster cold start and higher density.
Using the same technology that Amazon uses for AWS Lambda and AWS Fargate, Firecracker delivers the speed of containers with the security of VMs and has the potential to disrupt the current container and serverless technologies.
What is Weave Ignite?
While Firecracker has a ton of potential, it’s still in its early stages so getting it up and running can be a bit tedious. The goal of Ignite is to solve this issue by adopting its developer experience from containers.
With Ignite, you just pick a container image that you want to run as a VM and then execute ignite run
instead of docker run
.
There’s no need to use VM-specific tools to build .vdi
, .vmdk
, or .qcow2
images, just do a docker build
from any base image you want (e.g. ubuntu:18.04
from Docker Hub), and add your preferred content.
You can even use Buildpacks! As seen in my other blog post here. In this case, you would just follow the same steps, except you would build the image via the pack
command.
What is Firekube?
Firekube is a new open-source Kubernetes distribution that enables the use of Weave Ignite and GitOps to enable the setup of secure VM clusters. Firekube pulls everything from Git, detects your operating system and can boot up a secure cluster of VMs from nothing in 2.5 minutes.
A Firekube cluster has the following properties:
- Runs Kubernetes (now K8s, possibly K3s in future)
- High-grade VM security via the Firecracker KVM isolation
- Fast start-up and tear down of VMs e.g. for functions and serverless apps
- Scales from zero to production – uses standard k8s plugins for networking, etc
- “Lift and shift” software into VMs
- Run containers inside VMs or alongside VMs on the same CNI network
Creating a Firekube Cluster
Firekube is a Kubernetes cluster working on top of Ignite and Firecracker. Firekube clusters are operated with GitOps.
Ignite and Firecracker only works on Linux as they need KVM. However, it will also work on macOS using footloose: the Kubernetes nodes are then running inside containers.
Prerequisites: Docker, Git, kubectl 1.14+.
- Fork this repository.
- Clone your fork and
cd
into it. Use theSSH
git URL as the script will push an initial commit to your fork:
export user="" # Your GitHub handle or org git clone git@github.com:$user/wks-quickstart-firekube.git cd wks-quickstart-firekube
- Start the cluster:
./setup.sh
This step will take several minutes.
Export the KUBECONFIG
environment variable as indicated at the end of the installation:
export KUBECONFIG=/home/damien/.wks/weavek8sops/example/kubeconfig
Enjoy your Kubernetes cluster!
$ kubectl get nodes NAME STATUS ROLES AGE VERSION 67bb6c4812b19ce4 Ready master 3m42s v1.14.1 a5cf619fa058882d Ready <none> 75s v1.14.1
Watch GitOps in action
Now that we have a cluster installed, we can commit Kubernetes objects to the git repository and have them appear in the cluster. Let’s add podinfo, an example Go microservice, to the cluster.
kubectl apply --dry-run -k github.com/stefanprodan/podinfo//kustomize -o yaml > podinfo.yaml git add podinfo.yaml git commit -a -m 'Add podinfo Deployment' git push
A few seconds later, you should witness the apparition of a podinfo pod in the cluster:
$ kubectl get pods NAME READY STATUS RESTARTS AGE podinfo-677768c755-z76xk 1/1 Running 0 30s
To view podinfo
web UI:
- Expose
podinfo
locally:
kubectl port-forward deploy/podinfo 9898:9898
- Point your browser to
http://127.0.0.1:9898
:
Deleting a Firekube cluster
Run:
./cleanup.sh
Using a private git repository with firekube
To use a private git repository instead of a fork of wks-quickstart-firekube
:
- Create a private repository and push the
wks-quickstart-firekube
master
branch there. Use the SSH git URL when cloning the private repository:
git clone git@github.com:$user/$repository.git cd $repository git remote add quickstart git@github.com:weaveworks/wks-quickstart-firekube.git git fetch quickstart git merge quickstart/master git push
- Create an SSH key pair:
ssh-keygen -t rsa -b 4096 -C "damien+firekube@weave.works" -f deploy-firekube -N ""
- Upload the deploy key to your private repository (with read/write access):
- Start the cluster:
./setup.sh --git-deploy-key ./deploy-firekube
Final thoughts
You’ve now learned the basic steps it requires to provision a Kubernetes cluster based on Firecracker VM’s with Firekube. You should explore a bit of the different options the platform provides such as using Ignite to spin up MicroVM’s with Buildpack instead of Docker. I hope you liked this post, and I plan to dive into this a bit more in the future. Thanks for reading!