When setting up application delivery in Kubernetes, you must decide which format to use for managing the deployment configuration (parameterization, dependency management, configuration for different environments, etc.), as well as how to apply this configuration (the deployment mechanism).

Helm is built into werf and is used for these tasks. Configuration development and maintenance is carried out using Helm charts. As for the deployment process, Helm in werf provides some advanced features:

  • smart resource state tracking during deployment;
  • specifying the deployment order for any resources, not just hooks;
  • waiting for non-release resources to be created and ready;
  • integration of the assembly and deployment and other features.

werf strives to make working with Helm easier, more convenient and flexible without breaking backward compatibility with Helm charts, Helm templates, and Helm releases.

Basic deployment example

You only need two files and the werf converge command (run it in the application’s Git repository) to deploy a basic application:

# .helm/templates/hello.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello
spec:
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        app: hello
    spec:
      containers:
      - image: nginxdemos/hello:plain-text

# werf.yaml:
configVersion: 1
project: hello

werf converge --repo registry.example.org/repo --env production

The above command will deploy the hello Deployment to the hello-production Namespace.

Advanced deployment example

Here is a more complex deployment example involving image assembly and external Helm charts:

# werf.yaml:
configVersion: 1
project: myapp
---
image: backend
dockerfile: Dockerfile

# Dockerfile:
FROM node
WORKDIR /app
COPY . .
RUN npm ci
CMD ["node", "server.js"]

# .helm/Chart.yaml:
dependencies:
- name: postgresql
  version: "~12.1.9"
  repository: https://charts.bitnami.com/bitnami

# .helm/values.yaml:
backend:
  replicas: 1

# .helm/templates/backend.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend
spec:
  replicas: {{ $.Values.backend.replicas }}
  selector:
    matchLabels:
      app: backend
  template:
    metadata:
      labels:
        app: backend
    spec:
      containers:
      - image: {{ $.Values.werf.image.backend }}

werf converge --repo registry.example.org/repo --env production

The above command will build the backend image and then deploy the backend Deployment and the resources of the postgresql chart to the myapp-production Namespace.