Deploying with a hook command, without any manifests

[alexellis]

Expected behavior

I'd like to be able to deploy OpenFaaS functions via HTTP/REST using faas-cli deploy. This does work using an after hook, but a spurious and unnecessary Kubernetes YAML file is required, which makes using Skaffold confusing for users.

apiVersion: skaffold/v4beta2
kind: Config
metadata:
  name: quick
build:
  tagPolicy:
    inputDigest: {}
  artifacts:
  - image: alexellis2/quick
    custom:
      buildCommand: |
        sed 's/SKAFFOLD_IMAGE/IMAGE/g' ./stack.yml > /tmp/stack.yml
        DOCKER_BUILDKIT=1 faas-cli publish -f /tmp/stack.yml
      dependencies:
        paths:
          - ./quick/**/
    hooks:
      before:
        - command: ["kubectl", "delete", "job", "quick", "--ignore-not-found=true"]
      after:
        - command: ["faas-cli", "deploy"]
manifests:
  rawYaml:
  - ./warmup.yaml

Actual behavior

A dummy deployment file is required with 0 replicas i.e.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: quick-warmup
  namespace: openfaas-fn
  labels:
    app: quick
spec:
  replicas: 0
  selector:
    matchLabels:
      app: quick
  template:
    metadata:
      labels:
        app: quick
    spec:
      containers:
      - name: quick
        image: alexellis2/quick
        command: ["fwatchdog", "--version"]
        ports:
        - containerPort: 8080

OpenFaaS stack.yml

version: 1.0
provider:
  name: openfaas
  gateway: http://127.0.0.1:8080
functions:
  quick:
    lang: node16
    handler: ./quick
    image: ${SKAFFOLD_IMAGE:-alexellis2/quick:latest}

Steps to reproduce the behavior

skaffold version
v2.1.0

Full example plus additional context on the current issues: https://github.com/alexellis/openfaas-skaffold-faas-cli