Halyard

Halyard is in an experimentation phase where I will will be learning a lot and changing my opinion (and APIs) very often.

Halyard is a deployment and resource management tool. It packs an opinionated collection of best-in-class features of other similar tools with an emphasis on simplicity and efficiency.

Install

go install github.com/fvumbaca/halyard@latest

Usage

Base Deployment (base.yaml):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

Production Patches (prod.yaml):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
  annotations:
    halyard.sh/layer: "prod"
spec:
  replicas: 3
  template:
    spec:
      containers:
      - image: nginx:1.14.2

Preview rendered resources:

halyard template base.yaml prod.yaml

Update/Create resources:

halyard apply base.yaml prod.yaml

TODO

• Better cli flags/options
  • Default namespace override
• Layer filtering
• Resource association via selection labels
  • Resource cleanup
• Value based templating
  • Use variables/patching
• Apply Methods
  • Local and server-side resource validation/dry running
  • Look into server side apply
  • Look into patching over updating
• Track update history
  • store changes to resources in a history file or configmap