Docker Image

A Docker image with CDAP SDK pre-installed is available on the Docker Hub for download.

To use the Docker image:

  • Docker is available for a variety of platforms. Download and install Docker in your environment by following the platform-specific installation instructions from Docker.com to verify that Docker is working and has started correctly.

    If you are not running on Linux, you need to start the Docker Virtual Machine (VM) before you can use containers. For example, on Mac OS, use:

    $ boot2docker start
    $ boot2docker ip
    

    to determine the Docker VM’s IP address. You will need to use that address as the host name when either connecting to the CDAP UI or making an HTTP request.

    When you run boot2docker start, it will print a message on the screen such as:

    To connect the Docker client to the Docker daemon, please set:
        export DOCKER_HOST=tcp://192.168.59.103:2375
        export DOCKER_CERT_PATH=/Users/.../.boot2docker/certs/boot2docker-vm
        export DOCKER_TLS_VERIFY=1
    

    It is essential to run these export commands (or command, if only one). Otherwise, subsequent Docker commands will fail because they can’t tell how to connect to the Docker VM.

  • Once Docker has started, pull down the CDAP Docker Image from the Docker hub using:

    $ docker pull caskdata/cdap-standalone:3.2.2
    
  • Start the Docker CDAP Virtual Machine with:

    $ docker run -t -i -p 9999:9999 -p 10000:10000 caskdata/cdap-standalone:3.2.2
    
  • CDAP will start automatically once the CDAP Virtual Machine starts. CDAP’s Software Directory is under /opt/cdap/sdk.

  • Once CDAP starts, it will instruct you to connect to the CDAP UI with a web browser at http://localhost:9999. Replace localhost with the Docker VM’s IP address (such as 192.168.59.103) that you obtained earlier. Start a browser and enter the address to access the CDAP UI.

  • In order to begin building CDAP applications, have our recommended software and tools installed in your environment.

  • For a full list of Docker Commands, see the Docker Command Line Documentation.

Development Environment Setup

Creating an Application

When writing a CDAP application, it’s best to use an integrated development environment that understands the application interface to provide code-completion in writing interface methods.

The best way to start developing a CDAP application is by using the Maven archetype:

$ mvn archetype:generate \
      -DarchetypeGroupId=co.cask.cdap \
      -DarchetypeArtifactId=cdap-app-archetype \
      -DarchetypeVersion=3.2.2

This creates a Maven project with all required dependencies, Maven plugins, and a simple application template for the development of your application. You can import this Maven project into your preferred IDE—such as IntelliJ or Eclipse—and start developing your first CDAP application.

Using IntelliJ

  1. Open IntelliJ and import the Maven project.
  2. Go to menu File -> Import Project...
  3. Select the pom.xml in the Maven project’s directory.
  4. Select the Import Maven projects automatically and Automatically download: Sources, Documentation boxes in the Import Project from Maven dialog.
  5. Click Next, complete the remaining dialogs, and the new CDAP project will be created and opened.

Using Eclipse

  1. In your Eclipse installation, make sure you have the m2eclipse plugin installed.
  2. Go to menu File -> Import
  3. Enter maven in the Select an import source dialog to filter for Maven options.
  4. Select Existing Maven Projects as the import source.
  5. Browse for the Maven project’s directory.
  6. Click Finish, and the new CDAP project will be imported, created and opened.

Starting and Stopping Standalone CDAP

Use the cdap.sh script to start and stop the Standalone CDAP (the location will vary depending on where the CDAP SDK is installed):

$ cd cdap-sdk-3.2.2
$ ./bin/cdap.sh start
. . .
$ ./bin/cdap.sh stop

Or, if you are using Windows, use the batch script cdap.bat to start and stop the SDK.

Note that starting CDAP is not necessary if you use either the Virtual Machine or the Docker image, as they both start the Standalone CDAP automatically on startup.

Once CDAP is started successfully, in a web browser you will be able to see the CDAP UI running at http://localhost:9999, where you can deploy example applications and interact with CDAP.

Note that in the case of the Docker image, you will need to substitute the Docker VM’s IP address for localhost in the web browser address bar.

Building and Running CDAP Applications

See Building and Running CDAP Applications for information on accessing the CDAP CLI and CDAP SDK bin utilities, building examples, starting CDAP, and deploying, starting, and stopping applications.