Prerequisites
- Download and Install Docker
- Download and install Docker desktop
- IDE (Visual Studio Code)
- Sign-up to Docker Hub
- Install compose plugin
Get app
- Cloned node.js todo wep app github
Build the app’s container image
- In the app directory created a Dockerfile
- Added the folowing content to the Dockerfile [image]
- Build the container image
docker build -t sca-project
- Started the app container
docker run -dp 3000:3000 sa-project
- Opened web browser to localhost to see the app
Share application
- Created docker repository [image] on Docker Hub docker-repo
Docker login -u my_username
docker tag sca-project my_username/sca-project
docker push my_username/sca-project
Persist the database
docker volume create todo-db
docker run -dp 3000:3000 –mount type-volume, src=todo-db,target=/etc/todos sa-project
- Got to see my list being stored
-
docker volume inspect todo-db
Run app in a development container with a bind mount
docker run -dp 3000:3000 \
-w /app --mount type=bind,src="$(pwd)",target=/app \
node:18-alpine \
sh -c "yarn install && yarn run dev"
docker run -dp 3000:3000 `
-w /app --mount "type=bind,src=$pwd,target=/app" `
node:18-alpine `
sh -c "yarn install && yarn run dev"
docker logs -f <container-id>
- Make changes to app.js , save file (restarts the app inside the container automatically)
- Refresh the pages and saw my changes being reflected almost immediately
Multi container apps
- docker network create todo-app
docker run -d \
--network todo-app --network-alias mysql \
-v todo-mysql-data:/var/lib/mysql \
-e MYSQL_ROOT_PASSWORD=secret \
-e MYSQL_DATABASE=todos \
mysql:8.0
docker exec -it <my-sql-container-id> myqsl -u root -p
- Into mysql shell -> show databases; (don’t forget the semi-colons or else nothing will be displayed)
-
Exit
the mysql shell
Connect mysql
- docker network create todo-app
docker run -d `
--network todo-app --network-alias mysql `
-v todo-mysql-data:/var/lib/mysql `
-e MYSQL_ROOT_PASSWORD=secret `
-e MYSQL_DATABASE=todos `
mysql:8.0
Docker logs -f <container-id>
docker exec -it <my-sql-container-id> myqsl -p todos
- Into mysql shell ->
select * from todos_items
-
Exit
the mysql shellDocker compose
docker compose version
In the root folder created docker-compose.yml
Insert into docker-compose.yml file
services:
Define the app service
- docker-compose.yml file should look like:
services:
app:
image: node:18-alpine
command: sh -c "yarn install && yarn run dev"
ports:
- 3000:3000
working_dir: /app
volumes:
- ./:/app
environment:
MYSQL_HOST: mysql
MYSQL_USER: root
MYSQL_PASSWORD: secret
MYSQL_DB: todos
mysql:
image: mysql:8.0
volumes:
- todo-mysql-data:/var/lib/mysql
environment:
MYSQL_ROOT_PASSWORD: secret
MYSQL_DATABASE: todos
volumes:
todo-mysql-data:
Run the application stack
docker compose up -d
-
See the app stack in docker desktop dashboard
Describe apps using kubernetes yaml
Create deployment.yaml in the app root folder
Fill deploment.yaml with this code
apiVersion: apps/v1
kind: Deployment
metadata:
name: bb-demo
namespace: default
spec:
replicas: 1
selector:
matchLabels:
bb: web
template:
metadata:
labels:
bb: web
spec:
containers:
- name: bb-site
image: getting-started
imagePullPolicy: Never
---
apiVersion: v1
kind: Service
metadata:
name: bb-entrypoint
namespace: default
spec:
type: NodePort
selector:
bb: web
ports:
- port: 3000
targetPort: 3000
nodePort: 30002
Create and monitor deployment
- Enabled Kubernetes on Docker Desktop setting
Kubectl apply -f deplyment.yaml
Kubectl rollout status deployment/app-deployment
- Now can access the app with the yaml configuration nodePort :30002
-
Kubectl get deployments
-> view pods configured by yaml file] Kubectl get pods
Kubectl get services
Kubectl describe deploments
Scale deployment
Kubectl scale deployment/app-deployment –replicas=3
- Horizontal pod autoscaling
Kubectl autoscale deployment/app-deployment –min=3 –max–10 –cpu-percentage=80
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