Use relative paths in Kubernetes config

Question

The goal is to orchestrate both production and local development environments using Kubernetes. The problem is that hostPath doesn't work with relative path values. This results in slightly differing configuration files on each developer's machine to accommodate for the different project locations (i.e. "/my/absolute/path/to/the/project"):

apiVersion: v1 kind: Service metadata:   name: some-service   labels:     app: app spec:   type: LoadBalancer   ports:   - port: 80   selector:     app: app --- apiVersion: apps/v1 kind: Deployment metadata:   name: some-deploy spec:   selector:     matchLabels:       app: app   replicas: 1   template:     metadata:       labels:         app: app     spec:       containers:       - name: app         image: nginx:1.13.12-alpine         ports:         - containerPort: 80         volumeMounts:         - name: vol_example           mountPath: /var/www/html       volumes:         - name: vol_example           hostPath:             path: "/my/absolute/path/to/the/project"             type: Directory 

How can relative paths be used in Kubernetes config files? Variable replacements (such as $(PWD)/project) have been tried, but didn't seem to work. If config variables can work with volumes, this might help but unsure of how to achieve this.

Answer 1

As mentioned here kubectl will never support variable substitution.

You can create a helm chart for your app (yaml). It supports yaml template variables (among various other features). So you'll be able to pass hostPath parameter based on development or production.