Manageable Kubernetes manifests through composable, reusable syntax
The description format for Kubernetes manifests, as it stands today, is verbose and unintuitive. Anecdotally, it has been:
- Time consuming to write
- Error-prone, hard to get right without referring to documentation
- Difficult to maintain, read, and reuse
e.g. In order to create a simple nginx pod that runs on any host in region us-east1 or us-east2, here is the Kubernetes native syntax:
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: nginx
spec:
containers:
- name: nginx_container
image: nginx:latest
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: k8s.io/failure-domain
operator: In
values:
- us-east1
- matchExpressions:
- key: k8s.io/failure-domain
operator: In
value:
- us-east2The Short format is designed to be user friendly, intuitive, reusable, and maintainable. The same pod in Short syntax looks like
pod:
name: nginx
labels:
app: nginx
containers:
- name: nginx
image: nginx:latest
affinity:
- node: k8s.io/failure-domain=us-east1,us-east2Our approach is to reframe Kubernetes manifests in an operator-friendly syntax without sacrificing expressiveness.
Koki Short can transform Kubernetes syntax into Short and Short syntax back into Kubernetes. No information is lost in either direction.
For more information on Koki Short transformations, please refer to Resources.
Koki Short introduces the concept of modules, which are reusable collections of Short resources. Any resource can be reused multiple times in other resources and linked resources can be managed as a single unit on the Koki platform.
Any valid koki resource object can be reused. This includes subtypes of top-level resource types. For example, here's module called affinity_east1.yaml:
affinity:
- node: k8s.io/failure-domain=us-east-1This affinity value can be reused in any pod spec:
imports:
- affinity: affinity_east1.yaml
pod:
name: nginx
labels:
app: nginx
containers:
- name: nginx
image: nginx-latest
affinity: ${affinity} # re-use the affinity resource hereFor more information on Koki Modules, please refer to Modules.
In order to start using Short, simply download the binary from the releases page.
#start with any existing Kubernetes manifest file
$$ cat kube_manifest.yaml
apiVersion: v1
kind: Pod
metadata:
name: podName
namespace: podNamespace
spec:
hostAliases:
- ip: 127.0.0.1
hostnames:
- localhost
- myMachine
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- matchExpressions:
- key: k8s.io/failure-domain
operator: In
value: us-east1
containers:
- name: container
image: busybox:latest
ports:
- containerPort: 6379
hostPort: 8080
name: service
protocol: TCP
resources:
limits:
cpu: "2"
memory: 1024m
requests:
cpu: "1"
memory: 512m
#convert Kubernetes manifest into a Short syntax representation
$$ short -f kube_manifest.yaml
pod:
name: podName
namespace: podNamespace
affinity:
- node: k8s.io/failure-domain=us-east1
host_aliases:
- 127.0.0.1 localhost myMachine
containers:
- image: busybox
cpu:
min: "1"
max: "2"
mem:
min: "512m"
max: "1024m"
expose:
- port_map: "8080:6379"
name: service
#input can be json or yaml
$$ short -f kube_manifest.json -f kube_manifest2.yaml -f kube_multi_manifest.yaml
#stream input
$$ cat kube_manifest.yaml | short -
#revert to kubernetes type
$$ short -k -f koki_spec.yaml
#-k flag denotes that it should output Kubernetes manifest
For more information, refer to our getting started guide.
Koki is completely open source community driven, including the roadmaps, planning, and implementation. We encourage everyone to help us make Kubernetes manifests more manageable. We welcome Issues, Pull Requests and participation in our weekly meetings.
If you'd like to get started with contributing to Koki Short, read our Roadmap and start with any issue labelled help-wanted or good-first-issue