DevOps

index

CI/CD

• Continuous Integration and Delivery - CircleCI
• Jenkins
• GitHub Actions documentation - GitHub Docs

Docker

your-dockerhub-username == namespace

1) Make a Dockerfile with example contents as follows:

FROM node:20
 
# specify where whole project will install inside /usr/src
WORKDIR /usr/src/name_of_app 
 
COPY . .
 
RUN npm install
 
# change to where your server.js/index.js/app.js
WORKDIR /usr/src/name_of_app/src
 
EXPOSE 3000
 
CMD ["node", "server.js"]

2) Make a .dockerignore file with example contents as follows:

Dockerfile
 
.gitignore
node_modules
.env 
 
devlogs.txt

3) Make a docker-compose.yml file with example contents as follows:

• this file contains where to locate for environment variables while local development.

version: '3.8'
 
services:
  app:
    image: namespace/image_name
    build: .
    ports:
      - '3000:3000'
    env_file:
      - .env

4) Build an image:

• docker build . -t namespace/image_name ⇒ run this command where you have your docker files

5) Push image to DockerHub:

• docker push namespace/image_name

6) Pull images from DockerHub:

• docker pull namespace/image_name

---

Run an image locally (without env variables):

• You typically specify the image (app) and additional flags (e.g., -p for port mapping, -v for volumes).
• Example: docker run -p 3000:3000 app.
• Above examples tells that port 3000 of machine is mapped to port 3000 of container, so docker run -p machine_port:container_port image_name.

Run an image locally (with env variables):

docker run --env-file ./path/to/.env -p 3000:3000 namespace/image_name:latest