Docker — How to Get Started With Cloudera

This article offers information and code/scripts which could be used to get started with Cloudera using Docker. Please feel free to comment/suggest if I fail to mention one or more important points.

The following are the key points described in this article:

• Docker machine configuration
• Cloudera & Docker
• Test the Cloudera installation
• Scripts to install & run Cloudera

Docker Machine Configuration

To run Cloudera in a Docker container, one is required to make the following configuration to the Docker machine. Open Oracle VM Virtualbox Manager. Stop the default machine. Then, change the settings as shown below.

• Change the processor (core) setting to 2

Increase core size to 2

• Change the memory setting to 8192 (8 GB Ram)

Increase Memory Size to 8GB    

If not done, running “cloudera-manager –express” throws following error:

Memory related error while starting Cloudera manager service

Cloudera & Docker

• As of date, Cloudera docker image is of size 4.4 GB. Mind you this is going to take some time for image to build.
• For installation of Cloudera image, you could adopt following three methods:
  • Use command such as following:

    docker pull cloudera/quickstart:latest        

  • Use Docker file with following content:

    FROM cloudera/quickstart:latest        

    Save the file as cloudera.df and then, use following command to build the image:

    docker build -t cloudera -f cloudera.df .        

    The image is tagged as Cloudera.
  • Download the Cloudera quickstart tar file. Untar it and import it in Docker. The following command could be used:

    tar xzf cloudera-quickstart-vm-*-docker.tar.gz
    docker import - cloudera/quickstart:latest < cloudera-quickstart-vm-*-docker/*.tar          

• Once the Cloudera image is built, the following command could be used to run the container:

  docker run --privileged=true -ti -d -p 8888:8888 -p 80:80 -p 7180:7180 --name $1 --hostname=quickstart.cloudera -v /c/Users:/mnt/Users $cd_image /usr/bin/docker-quickstart     

  Note that image is named/tagged as Cloudera. You could as well check “docker images” command to find the tag name of Cloudera image and use it in place of “cloudera”. Also, note the port such as 7180, 8888 mapped from guest to host.

Test the Cloudera Installation

Execute the following command to start the Cloudera service assuming that you started the container with the name as “cdh”. Use the scripts below to start “cdh” cloudera container.

docker exec -ti cdh /home/cloudera/cloudera-manager --express

With the above command, Cloudera starts as shown below:

Cloudera starts in a Docker container

Open a browser and access the following command: http://192.168.99.100:7180/. It will open up the login page for Cloudera Manager. Enter the login/password as cloudera/cloudera and you are all set!

Scripts to install & run Cloudera

The following is the script which could be used to install/build the image and run the cloudera container.

• cloudera.df. This is dockerfile for building Cloudera image

  FROM cloudera/quickstart:latest     

• runCloudera.sh. This is a script to build the Cloudera image (if not present) and start the container.

  #!/bin/sh
  
  if [ $# == 0 ]; then
    echo "This script expect container name argument. Example: ./runCloudera.sh cdh"
    exit 100
  fi
  
  docker stop $1;docker rm $1
  
  # Build Cloudera image if it does not exists
  #
  cd_image="cloudera"
  cd_df="cloudera.df"
  if [ `docker images $cd_image | wc -l` -lt 2 ]; then
    echo "Docker Image $cd_image do not exist..."
    echo "Builing docker image $cd_image"
    if [ -f $cd_df ]; then
      docker build -t $cd_image -f $cd_df .
    else
      echo "Can't find Dockerfile $cd_df in the current location"
      exit 200
    fi
  fi
  
  docker run --privileged=true -ti -d -p 8888:8888 -p 80:80 -p 7180:7180 --name $1 --hostname=quickstart.cloudera -v /c/Users:/mnt/Users $cd_image /usr/bin/docker-quickstart      

Open a Docker terminal, place both the files within a folder and execute the command such as “./runCLoudera.sh cdh”. This should build the image and start the container named “cdh”.