<10s Docker/NPM build & develop from a docker container

build-docker.sh

#!/bin/bash

# This is the "build" command in the package.json.
# This build command will keep build time < 10s (except when a npm dependency changes).

#  Rational: Docker's cache check the file hash for each line
#  when a file has changed in any way it will bust the cache.
#  This is problematic for package.json files that change
#  frequently even with the dependencies are the same.
#  In order to correct this we'll copy just the package.json
#  dependencies to docker, run `npm install` then override it
#  with the project files. That will build times to < 10s.

node -e \" \                                   
  require('fs').writeFileSync( \                          
  '.deps.json', \
  JSON.stringify({ \
    dependencies:require('./package.json').dependencies \
  }))\" && \                                               # create file with only npm dependencies
docker build -t my/project . && \                          # build the docker container
rm .deps.json                                              # remove the dependencies-only file

Dockerfile

FROM node

RUN mkdir -p /app
WORKDIR /app

# .deps.json will only bust the cache when the package.json dependencies change
COPY .deps.json /app/package.json
RUN npm install

# cache will almost always bust here, but it's only copying files
COPY package.json /app/package.json
COPY src /app/src

CMD npm start

npm-watch.sh

#!/bin/bash

# This is the "watch" command in the package.json.
# Use this to develop from inside a docker container but using your local file system.
# It work especially great for project using old version of node.


docker stop myProject 2>/dev/null      # stop running container
docker rm myProject 2>/dev/null        # remove container logs 

docker run -d \                        # start new daemon
  -e "DEBUG=express:*,my_project:*" \  # turn on NPM debugging
  --name myProject \                   # name the container
  -p 3000:3000 \                       # map internal to external port
  -v /Users/puppybits/myProject:/app \ # override container w/ local dev files
  my/project \                         # container name
  nodemon -L server/index.js           # start nodemon to watch for changes

docker logs -f myProject               # watch container logs

# single line command
docker stop myProject 2>/dev/null && docker rm myProject 2>/dev/null && docker run -d -e "DEBUG=express:*,my_project:*" --name myProject -p 3000:3000 -v /Users/puppybits/myProject:/app my/project nodemon server/index.js && docker logs -f myProject

package.json

{
  "name": "myProject",
  "version": "1.0.0",
  "description": "docker / npm sample",
  "license": "UNLICENSED",
  "main": "server/index.js",
  "scripts": {
    "start": "PORT=8080 node server/index.js",
    "build": "node -e \"require('fs').writeFileSync('.deps.json',JSON.stringify({dependencies:require('./package.json').dependencies}))\" && docker build -t my/project . && rm .deps.json",
    "watch": "docker stop myProject 2>/dev/null && docker rm myProject 2>/dev/null && docker run -d -e \"DEBUG=express:*,my_project:*\" --name myProject -p 3000:3000 -v /Users/puppybits/myProject:/app my/project nodemon -L server/index.js && docker logs -f myProject",
    "ssh": "docker exec -ti myProject /bin/bash",
    "deploy": "gcloud preview app deploy --stop-previous-version"
  },
  "author": "Puppybits <puppybits@gmail.com> (https://twitter.com/puppybits)",
  "dependencies": {
    "body-parser": "*",
    "express": "*",
    "nodemon": "*"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/puppybits"
  }
}