Containerizing node.js applications

Build a simple nodejs application

Build the node application docker image

cd building-a-nodejs-app

# build
docker build -t my-node-app .

# docker image size
docker inspect my-node-app

# run
docker run --init --rm --publish 3000:3000 my-node-app

Preparing a multi stage build process

cd multi-stage-build

# build
docker build -t multi-node -f multi.node.Dockerfile .

# docker image size
docker inspect multi-node

# run
docker run --init --rm -p 3000:3000 multi-node

Create application using create-react-app and serve static files using nginx

cd serve-static-files-nginx

# build
docker build -t static-app .

# run
# Port exposed to host is 8080. Internal port used is 80. And nginx uses 80 as the default port
docker run --init --rm -p 8080:80 static-app

# Using docker bind mount. Below command mounts the /build directory inside nginx html directory
docker run --mount type=bind,source="$(pwd)"/build,target=/usr/share/nginx/html -p 8080:80 nginx:1.17-alpine

Bind mount

• Bind mount are works great when you need to share data between host and container.
• Build image docker build --tag=incrementor-bind .
  • New image create with the tag name incrementor-bind
• Run container docker run --rm --env DATA_PATH=data/num.txt --mount type=bind,source="$(pwd)"/incrementor-data,target=/src/data incrementor-bind

Volume mount

• Using bind volumes containers can maintain states between runs.
• Build image docker build --tag=incrementor-volume .
• Run container docker run --rm --env DATA_PATH=/data/num.txt --mount type=volume,src=incrementor-data,target=/data incrementor-volume

Try all example commands within this directory

• --env Passes process environment variable. For example docker run --rm --env DATA_PATH=data/num.txt --mount type=bind,source="$(pwd)"/incrementor-data,target=/src/data incrementor-bind. Here DATA_PATH is the process environment variable passed. Node application can use this data by process.env.DATA_PATH
• --rm Deletes the container after exiting the process. Try running any container with and without this flag to see the difference. For example docker run --rm --env DATA_PATH=data/num.txt --mount type=bind,source="$(pwd)"/incrementor-data,target=/src/data incrementor-bind deletes the container after exiting the run process, but docker run --env DATA_PATH=data/num.txt --mount type=bind,source="$(pwd)"/incrementor-data,target=/src/data incrementor-bind doesn't deletes the container after exiting the process
• src or source mount source directory i.e docker run --rm --env DATA_PATH=/data/num.txt --mount type=volume,src=incrementor-data,target=/data incrementor-volume or docker run --rm --env DATA_PATH=/data/num.txt --mount type=volume,source=incrementor-data,target=/data incrementor-volume
• --init Gracefully exits node process where listen is used

Inspired & credits to @btholt for creating a course in FEM & sharing complete into to containers

• Docker netowkring Crash Course By Hussein Nasser