[Docker-101] Tutorial 2

Deploy a Node.js application in Docker container

Sat, 18 Aug 2018

docker-nodejs

  1. Create Dockerfile

    FROM node:7-alpine

# Create a directory
RUN mkdir -p /src/app

# To ensure that a future commands are executed in /src/app
WORKDIR /src/app

# Copy from <host_path> to <container_path>
COPY . /src/app 

RUN npm install

EXPOSE 3000

# will be run when container launch
CMD npm start

    RUN is an image build step, the state of the container after a RUN command will be committed to the docker image. A Dockerfile can have many RUN steps that layer on top of one another to build the image.

    CMD is the command the container executes by default when you launch the built image. A Dockerfile can only have one CMD. The CMD can be overridden when starting a container with docker run $image $other_command.

  2. Build docker images

    docker build -t nodejs:v1 .
    $ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
nodejs              v1                  a365133f2e28        6 seconds ago       67.5MB

  3. Run container with 80 port

    $ docker run -d -p 80:3000 --name node-app nodejs:v1
3dbe413b3a1c00aadbf97a44516562e49df84c688a6b6eb872aa4b161bc678a4
    $ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
3dbe413b3a1c        nodejs:v1           "/bin/sh -c 'npm sta…"   28 seconds ago      Up 28 seconds       0.0.0.0:80->3000/tcp   node-app
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