title: ESTABLISH SSH CONNECTION FOR USER: None when specify a single host on the command line
body: <p>how to set ssh or ansible_user when specify a single host on the command line?</p>
  
  <p>when i specify a single host as following:</p>
  
  <pre><code>$ansible-playbook -i "ceph1," jdk.yml
  TASK [hadoop : create hadoop group] ********************************************
  task path: /playbooks/yarn/roles/hadoop/tasks/install.yml:2
  &lt;ceph1&gt; ESTABLISH SSH CONNECTION FOR USER: None
  </code></pre>
  
  <p>Both the ssh conneciton user and {{ansible_user}} are none, but  i have defined it in ssh/config</p>
  
  <pre><code>$cat jdk.yml
  - hosts: all
    vars_files:
       - default.yml
    roles:
       - role: jdk
  
  $cat role/jdk/tasks/main.yml
  
  - name: set java home
    lineinfile: dest=/home/{{ ansible_ssh_user }}/.bashrc
                line={{ item }}
    with_items:
      - export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
  
  $cat hosts
      ceph1 ansible_user=ubuntu
  
  $cat ~/.ssh/config
      Host ceph1
      User ubuntu
  </code></pre>
  
  <p>of course runnig the below is ok</p>
  
  <pre><code>$ansible-playbook  jdk.yml
  </code></pre>