Kathleen Juell, Digital Ocean - Containers are an essential part of today's microservice ecosystem, as they allow developers and operators to maintain standards of reliability and reproducibility in fast-paced deployment scenarios. And while there are best practices that extend across stacks in containerized environments, there are also things that make each stack distinct, starting with the application image itself. This talk will dive into some of these particularities, both at the image and service level, while also covering general best practices for building and running Node applications with database backends using Docker and Compose.

1. How to Build and Run Node Applications With
Docker and Compose
- Kathleen Juell, Developer @ DigitalOcean, @katjuell

6. ● Building containers
● Containerizing for development
with Compose
● Containerizing for deployment

10. Containers

11. Containers and VMs
● Container features
○ Lightweight
○ Portable
○ Isolated
Containers Virtual Machines

12. 1. Building an Image for a
Node App

13. Dockerfile
CODE EDITOR
FROM node:12-alpine
1. Build the base

14. Dockerfile
CODE EDITOR
FROM node:12-alpine
RUN apk add --update --no-cache vim
1. Build the base
2. Install
container-level
dependencies

15. Dockerfile
CODE EDITOR
FROM node:12-alpine
RUN apk add --update --no-cache
curl
git
vim
1. Build the base
2. Install
container-level
dependencies

16. Dockerfile
CODE EDITOR
FROM node:12-alpine
RUN apk add --update --no-cache
curl
git
vim
RUN mkdir -p /home/node/app/node_modules && chown
-R node:node /home/node/app
USER node
WORKDIR /home/node/app
1. Build the base
2. Install
container-level
dependencies
3. Set working
directory & user

17. Dockerfile
CODE EDITOR
FROM node:12-alpine
RUN apk add --update --no-cache
curl
git
vim
RUN mkdir -p /home/node/app/node_modules && chown
-R node:node /home/node/app
USER node
WORKDIR /home/node/app
COPY package*.json ./
COPY --chown=node:node . .
RUN npm install
1. Build the base
2. Install
container-level
dependencies
3. Set working
directory & user
4. Copy code, set
permissions, and
install project
dependencies

18. Dockerfile
CODE EDITOR
FROM node:12-alpine
RUN apk add --update --no-cache
curl
git
vim
RUN mkdir -p /home/node/app/node_modules && chown
-R node:node /home/node/app
USER node
WORKDIR /home/node/app
COPY package*.json ./
COPY --chown=node:node . .
RUN npm install
EXPOSE 8080
CMD [ “node”, “app.js” ]
1. Build the base
2. Install
container-level
dependencies
3. Set working
directory & user
4. Copy code, set
permissions, and
install project
dependencies
5. Expose ports and
invoke commands

19. Up & Running

20. ● Build: docker build -t <docker-demo> .
● Run: docker run --name <docker-demo> -p
80:8080 -d <docker-demo>
● Logs: docker logs <container-id>
● Check: docker ps -a
● Exec: docker exec -it <container-id> sh

21. Demo Time

22. 2. Development Setup
with Compose

23. A. Prepare the Application

24. ● Service: A running container
● Service definition: Information
about how the container will run

25. ● Service: A running container
● Service definition: Information about how
the container will run
● 12FA principles to consider: 1. Store config
in the environment & separate it from code;
2. Treat backing services as attached
resources

26. Where to look & what to do?
● Where are your database credentials defined?
● Anything else that talks to an attached service?

27. Before:
const mongoose = require('mongoose');
const MONGO_USERNAME = 'sammy';
const MONGO_PASSWORD = 'your_password';
const MONGO_HOSTNAME = '127.0.0.1';
const MONGO_PORT = '27017';
const MONGO_DB = 'sharkinfo';
const url =
`mongodb://${MONGO_USERNAME}:${MONGO_PASSWORD}@${MONGO_H
OSTNAME}:${MONGO_PORT}/${MONGO_DB}?authSource=admin`;
mongoose.connect(url, {useNewUrlParser: true});

28. After:
const mongoose = require('mongoose');
const {
MONGO_USERNAME,
MONGO_PASSWORD,
MONGO_HOSTNAME,
MONGO_PORT,
MONGO_DB
} = process.env;
const url =
`mongodb://${MONGO_USERNAME}:${MONGO_PASSWORD}@${MONGO_H
OSTNAME}:${MONGO_PORT}/${MONGO_DB}?authSource=admin`;
mongoose.connect(url, {useNewUrlParser: true});

29. Environment Variables:
● Use .env file

30. Environment Variables:
● Use .env file
MONGO_USERNAME=sammy
MONGO_PASSWORD=your_password
MONGO_PORT=27017
MONGO_DB=sharkinfo

31. Environment Variables:
● Use .env file
● Credentials manager (orchestrated
environments)

32. One more stop at `db.js`:
. . .
const options = {
useNewUrlParser: true,
reconnectTries: Number.MAX_VALUE,
reconnectInterval: 500,
connectTimeoutMS: 10000,
};
const url =
`mongodb://${MONGO_USERNAME}:${MONGO_PASSWORD}@${MONGO_HOSTNAME}:${MO
NGO_PORT}/${MONGO_DB}?authSource=admin`;
mongoose.connect(url, options).then( function() {
console.log('MongoDB is connected');
})
.catch( function(err) {
console.log(err);
});

33. And an addition to `package.json`:
...
"dependencies": {
"ejs": "^2.6.1",
"express": "^4.16.4",
"mongoose": "^5.4.10"
},
"devDependencies": {
"nodemon": "^1.18.10"
}
}

34. B. Write the Compose File

35. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
1. Tell Compose
how it should
build the app
image

36. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
env_file: .env
environment:
- MONGO_HOSTNAME=db
volumes:
- .:/home/node/app
- node_modules:/home/node/app/node_modules
1. Tell Compose
how it should
build the app
image
2. Add environment
and volume info

37. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
env_file: .env
environment:
- MONGO_HOSTNAME=db
volumes:
- .:/home/node/app
- node_modules:/home/node/app/node_modules
1. Tell Compose
how it should
build the app
image
2. Add environment
and volume info

38. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
env_file: .env
environment:
- MONGO_HOSTNAME=db
volumes:
- .:/home/node/app
- node_modules:/home/node/app/node_modules
1. Tell Compose
how it should
build the app
image
2. Add environment
and volume info

39. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
env_file: .env
environment:
- MONGO_HOSTNAME=db
volumes:
- .:/home/node/app
- node_modules:/home/node/app/node_modules: delegated
1. Tell Compose
how it should
build the app
image
2. Add environment
and volume info

40. Compose
File
CODE EDITOR
version: '3.4'
services:
nodejs:
build:
context: .
dockerfile: Dockerfile
image: nodejs
container_name: nodejs
env_file: .env
environment:
- MONGO_HOSTNAME=db
volumes:
- .:/home/node/app
- node_modules:/home/node/app/node_modules: delegated
ports:
- "80:8080"
command: ./wait-for.sh db:27017 --
/home/node/app/node_modules/.bin/nodemon app.js
1. Tell Compose
how it should
build the app
image
2. Add environment
and volume info
3. Add ports and
commands

41. Compose
File
CODE EDITOR
. . .
db:
image: mongo:4.2-bionic
container_name: db1. Tell Compose
what image it
should use

42. Compose
File
CODE EDITOR
. . .
db:
image: mongo:4.2-bionic
container_name: db
env_file: .env
environment:
- MONGO_INITDB_ROOT_USERNAME=$MONGO_USERNAME
- MONGO_INITDB_ROOT_PASSWORD=$MONGO_PASSWORD
1. Tell Compose
what image it
should use
2. Add environment
info

43. Compose
File
CODE EDITOR
. . .
db:
image: mongo:4.2-bionic
container_name: db
env_file: .env
environment:
- MONGO_INITDB_ROOT_USERNAME=$MONGO_USERNAME
- MONGO_INITDB_ROOT_PASSWORD=$MONGO_PASSWORD
volumes:
- dbdata:/data/db
1. Tell Compose
what image it
should use
2. Add environment
info
3. Add volumes

44. Compose
File
CODE EDITOR
. . .
volumes:
dbdata:
node_modules:1. Add top-level
volumes key for
named volumes

45. ● Run: docker-compose up -d
● List: docker-compose ps
● Logs: docker-compose logs <container>
● Exec: docker-compose exec <container>
<command>
● Down: docker-compose down

46. Demo Time

47. 3. Preparing to Deploy

48. Compose
File
TODO
CODE EDITOR
version: '3.4'
services:
nodejs:
image: <yourDockerHubUsername>/nodejs:v1
container_name: nodejs
1. Application
images: Pull from
registry

49. Compose
File
TODO
CODE EDITOR
version: '3.4'
services:
nodejs:
image: <yourDockerHubUsername>/nodejs:v1
container_name: nodejs
volumes:
- app_code:/home/node/app
- node_modules:/home/node/app/node_modules
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app
code

50. Compose
File
TODO
CODE EDITOR
webserver:
image: nginx:1.17-alpine
container_name: webserver
ports:
- "80:80"
volumes:
- app_code:/var/www/html
- ./nginx-conf:/etc/nginx/conf.d
depends_on:
- nodejs
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app code
3. Add a web server

51. Compose
File
TODO
CODE EDITOR
webserver:
image: nginx:1.17-alpine
container_name: webserver
ports:
- "80:80"
volumes:
- app_code:/var/www/html
- ./nginx-conf:/etc/nginx/conf.d
depends_on:
- nodejs
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app code
3. Add a web server

52. Compose
File
TODO
CODE EDITOR
certbot:
image: certbot/certbot
container_name: certbot
volumes:
- certbot-etc:/etc/letsencrypt
- certbot-var:/var/lib/letsencrypt
- app_code:/var/www/html
depends_on:
- webserver
command: certonly --webroot --webroot-path=/var/www/html
--email sammy@example.com --agree-tos --no-eff-email --staging -d
example.com -d www.example.com
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app code
3. Add a web server

53. Compose
File
TODO
CODE EDITOR
webserver:
image: nginx:1.17-alpine
container_name: webserver
ports:
- "80:80"
volumes:
- app_code:/var/www/html
- ./nginx-conf:/etc/nginx/conf.d
- certbot-etc:/etc/letsencrypt
- certbot-var:/var/lib/letsencrypt
depends_on:
- nodejs
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app code
3. Add a web server

54. Compose
File
TODO
CODE EDITOR
webserver:
image: nginx:1.17-alpine
container_name: webserver
ports:
- "80:80"
volumes:
- app_code:/var/www/html
- ./nginx-conf:/etc/nginx/conf.d
- certbot-etc:/etc/letsencrypt
- certbot-var:/var/lib/letsencrypt
depends_on:
- nodejs
1. Application
images: Pull from
registry
2. Use Named
Volumes: Prefer
them over bind
mounts for app code
3. Add a web server
4. Docker for certs:
How To Secure a
Containerized Node
Application with Let's
Encrypt

55. How to Build and Run Node Applications With
Docker and Compose
- Kathleen Juell, Developer @ DigitalOcean, @katjuell