title: Error in Installation of Openstack Kilo on CentOS7
body: <p>I was installing OpenStack Kilo on CentOS. I gave the command to run the main installation script with the following command > </p>
  
  <pre><code>#packstack --allinone --os-heat-install=y
  </code></pre>
  
  <p>I get the following error </p>
  
  <pre><code>Pre installing Puppet and discovering hosts' details[ ERROR ]
  
  ERROR : Failed to run remote script, stdout: Loaded plugins: fastestmirror, langpacks
  Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&amp;arch=x86_64&amp;repo=os&amp;infra=stock error was
  14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Name or service not known"
  
  stderr: Warning: Permanently added '172.16.34.145' (ECDSA) to the list of known hosts.
  + trap t ERR
  + yum install -y puppet hiera openssh-clients tar nc rubygem-json
  
  
  One of the configured repositories failed (Unknown),
  and yum doesn't have enough cached data to continue. At this point the only
  safe thing yum can do is fail. There are a few ways to work "fix" this:
  
   1. Contact the upstream for the repository and get them to fix the problem.
  
   2. Reconfigure the baseurl/etc. for the repository, to point to a working
      upstream. This is most often useful if you are using a newer
      distribution release than is supported by the repository (and the
      packages for the previous distribution release still work).
  
   3. Disable the repository, so yum won't use it by default. Yum will then
      just ignore the repository until you permanently enable it again or use
      --enablerepo for temporary usage:
  
          yum-config-manager --disable &lt;repoid&gt;
  
   4. Configure the failing repository to be skipped, if it is unavailable.
      Note that yum will try to contact the repo. when it runs most commands,
      so will have to try and fail each time (and thus. yum will be be much
      slower). If it is a very temporary problem though, this is often a nice
      compromise:
  
          yum-config-manager --save --setopt=&lt;repoid&gt;.skip_if_unavailable=true
  
  Cannot find a valid baseurl for repo: base/7/x86_64
  ++ t
  ++ exit 1
  </code></pre>
  
  <p>Thank you in advance.</p>