Notes for Docker

• Docker

1. Docker Basics

Docker is an open standard platforms for developing, packaging, and running portable distributed applications.

What makes Docker images unique and different from other virtual machines is that while each virtual machine image runs on a separate guest OS, the Docker images run within the same OS kernel.

Install Docker with the Official Get Started with Docker

Docker cheet sheet

An instance of an image is called container.

List all images: $docker images

List all containers: $docker ps -a

Download a pre-built image (ubuntu): $docker pull ubuntu

Run a container from a specific image:

$ sudo docker run -i -t <image_id || repository:tag> /bin/bash

Start a existed container:

$ sudo docker start -i <image_id>

Attach a running container:

$ sudo docker attach <container_id>

Exit without shutting down a container:

[Ctrl-p] + [Ctrl-q]

Start a new container:

$ JOB=$(docker run -d ubuntu /bin/sh -c "while true; do echo Hello world; sleep 1; done")

Stop the container: $ docker stop $JOB

Start the container: $ docker start $JOB

Restart the container: $ docker restart $JOB

Kill a container: $ docker kill $JOB

Remove a container:

$ docker stop $JOB # Container must be stopped to remove it $ docker rm $JOB or $ docker rm <container_id>

Remove an image:

$ docker rmi <image_id> # container must be removed first

Search for images command:$ docker search <image_name>

Pull image: $ docker pull <image_name>

Commit your container to a new named image:

# run a container
$ docker run -it <image_name> /bin/bash
# make some changes in the container, then exit.
# commit a copy of this container to an image.
$ docker commit -m "changes content" <container_id> <new_image_name>
# -m is for the commit message

Build an image:

# create a Dockerfile like the following:
FROM ubuntu:14.04
MAINTAINER Kate Smith <ksmith@example.com>
RUN apt-get update && apt-get install -y ruby ruby-dev
RUN gem install sinatra

$ docker build - t <user>/<image_name>:<tag> .

Docker command flags:

• -d: run in background
• -P: map any require network
• -i: interactive

2. Docker for Hadoop

The image I used for launch Hadoop is Hadoop-docker. Following the instruction on the readme file, you can launch and test the Hadoop platfrom pretty easily.

To use the image: $ docker run -it sequenceiq/hadoop-docker:2.7.1 /etc/bootstrap.sh -bash

3. Docker for Spark

Docker-spark

To use the image: $ docker run -d -h sandbox sequenceiq/spark:1.6.0 -d