Example of how you could template a manifest file and what values you would make variable

Example manifest template

## template with a lot of options

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{.Values.name}}
  namespace: {{.Values.environ}}
spec:
  replicas: {{.Values.replicas}}
  template:
    metadata:
      labels:
        app: {{.Values.name}}
        tier: {{ .Values.tier }}
        version: {{.Values.version}}
      annotations:
    spec:
      containers:
      - name: {{.Values.name}}
        image: gcr.io/{{.Values.regnamespace}}/{{.Values.name}}:{{.Values.version}}
        resources:
          requests:
            memory: {{ .Values.requestmemory }}
            cpu: {{ .Values.requestcpu }}
          limits:
            memory: {{ .Values.limitmemory }}
            cpu: {{ .Values.limitcpu }}
        readinessProbe:
          httpGet:
            path: {{ .Values.readinessprobepath }}
            port: {{ .Values.serviceport }}
          initialDelaySeconds: 120
          timeoutSeconds: 1
          periodSeconds: 3
        livenessProbe:
          httpGet:
            path: {{ .Values.livenessprobepath }}
            port: {{ .Values.serviceport }}
          initialDelaySeconds: 120
          periodSeconds: 10
        env:
        - name: SOME_ENV_VAR
          valueFrom:
            configMapKeyRef:
              name: env-config
              key: env.name
        imagePullPolicy: Always
        ports:
        - containerPort: {{ .Values.serviceport }}
      nodeSelector:
        environment: {{.Values.environ}}

---

apiVersion: v1
kind: Service
metadata:
  name: {{.Values.name}}
  namespace: {{.Values.environ}}
  annotations:
    prometheus.io/probe: "{{ .Values.prometheusprobe }}"
    prometheus.io/path: "{{ .Values.prometheusprobepath }}"
spec:
  ports:
    - protocol: TCP
      port: {{ .Values.serviceport }}
  selector:
    app: {{.Values.name}}


-------------------------------


## values for above template

---
name: cool-api # name of application. Will be used as pod and service name
regnamespace: releases # registry namespace
version: 1.1.0 # container/app version. Will be used as image tag
replicas: 2
environ: stage # In this example it is used to choose what hosts to go to
tier: backend # just for metadata purposes
requestMemory: "1.5Gi"
requestCPU: "100m"
limitMemory: "1.9Gi"
limitCPU: "200m"
servicePort: "8080" # port that will be used for the service and container
livenessProbePath: "/healthcheck/version" # paths to use for probes
readinessProbePath: "/healthcheck/version" # paths to use for probes
prometheusProbePath: "/healthcheck/version" # paths to use for probes