title: Ansible - ERROR! the field 'hosts' is required but was not set
body: <p>I've an error when I launch a playbook but I don't found why....</p>
  
  <blockquote>
    <p>ERROR! the field 'hosts' is required but was not set</p>
  </blockquote>
  
  <p>There is my main.yml :</p>
  
  <pre><code>---
  - hosts: hosts
  - vars: 
    - elasticsearch_java_home: /usr/lib/jmv/jre-1.7.0
    - elasticsearch_http_port: 8443
  
  - tasks: 
    - include: tasks/main.yml
  
  - handlers:
    - include: handlers/main.yml
  </code></pre>
  
  <p>And my /etc/ansible/hosts :</p>
  
  <pre><code>[hosts]
  10.23.108.182
  10.23.108.183
  10.23.108.184
  10.23.108.185
  </code></pre>
  
  <p>When I test a ping, all is good :</p>
  
  <pre><code>[root@poste08-08-00 elasticsearch]# ansible hosts -m ping
  10.23.108.183 | SUCCESS =&gt; {
      "changed": false, 
      "ping": "pong" }
  10.23.108.182 | SUCCESS =&gt; {
      "changed": false, 
      "ping": "pong" }
  10.23.108.185 | SUCCESS =&gt; {
      "changed": false, 
      "ping": "pong" }
  10.23.108.184 | SUCCESS =&gt; {
      "changed": false, 
      "ping": "pong" }
  </code></pre>
  
  <p>Please, help me :)
  Regards,</p>