---
  - name: Copy Apache HDFS init script.
    template: src=hdfs-init.j2 dest=/etc/init.d/hdfs-init owner=hduser group=lambda mode=0740

  - name: Copy Apache Yarn init script.
    template: src=yarn-init.j2 dest=/etc/init.d/yarn-init owner=hduser group=lambda mode=0740

  - name: Format Apache HDFS.
    shell: su - hduser -c "yes | {{ installation_path }}/hadoop/bin/hadoop namenode -format"
    tags:
      - format-hdfs

  - name: Start Apache HDFS.
    shell: /etc/init.d/hdfs-init start > /dev/null &
    tags:
      - start-hdfs

  - name: Wait for Apache HDFS to become available.
    wait_for: host="{{ hostvars[inventory_hostname]["internal_ip"] }}" port=9000
    tags:
      - start-hdfs

  - name: Start Apache Yarn.
    shell: /etc/init.d/yarn-init start > /dev/null &
    tags:
      - start-yarn

  - name: Wait for Apache Yarn to become available.
    wait_for: host="{{ hostvars[inventory_hostname]["internal_ip"] }}" port=8050 # 8050 is the port of the resource manager.
    tags:
      - start-yarn

  - name: Create Apache HDFS user directory.
    command: "{{ installation_path }}/hadoop/bin/hadoop fs -mkdir /user"
    tags:
      - create-dirs

  - name: Create Apache HDFS user/hduser directory. 
    command: "{{ installation_path }}/hadoop/bin/hadoop fs -mkdir /user/hduser"
    tags:
      - create-dirs