What is an example of Infrastructure as a Code(IaC)?

Question

I ran into the word "IaaC" (or IaC) many times. When I googled it, it told me :

Infrastructure as code(IaC) is the process of managing and provisioning computer data centers through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools.

Can yaml files used in Kubernetes be an example of IaC? Maybe even Dockerfile can be considered as such? If not, could you give me some examples of IaC?

For example :

apiVersion: v1
kind: Service
metadata:
  name: my-nginx-svc
  labels:
    app: nginx
spec:
  type: LoadBalancer
  ports:
  - port: 80
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

Answer 1

There are a number of steps which a IP Ops need to do to release/update the application running on the internet. Few examples of the tasks are

1. Provisioning new virtual machines, like starting the VM with the required memory and specs.

2. Installing the required software and dependency

3. Managing and scaling the infrastructure.

4. Repeating all of the configurations we've made again and again.

Infrastructure as a code means automating the steps required to deploy our application on the internet. Since using docker and k8s we are automating the deployment process, it is also considered infrastructure as a code.

Example

# define services (containers) that should be running
services:
  mongo-database:
    image: mongo:3.2
    # what volumes to attach to this container
    volumes:
      - mongo-data:/data/db
    # what networks to attach this container
    networks:
     - raddit-network

  raddit-app:
    # path to Dockerfile to build an image and start a container
    build: .
    environment:
      - DATABASE_HOST=mongo-database
    ports:
      - 9292:9292
    networks:
     - raddit-network
    # start raddit-app only after mongod-database service was started
    depends_on:
      - mongo-database

# define volumes to be created
volumes:
  mongo-data:
# define networks to be created
networks:
  raddit-network:

This docker compose file installs the dependency mongo-database by itself also it installs the main application raddit-app, and specifies the port the application listens for.

Source: Artemmkin / infrastructure-as-code-tutorial