chef bootstrap template to use old ohai hostname plugin via custom plugins

1-README.txt

This bootstrap template will download the old ohai hostname plugin from github and use it as a custom plugin on bootstrap.

https://github.com/chef/ohai/issues/420

USE:
1. download and place chef-full-old-hostname.erb in ~/.chef/bootstrap/ on your workstation
2. pass "--bootstrap-template chef-full-old-hostname" to your knife bootstrap command

This requires Ohai 8.6.0+, which should be included in Chef 12.4.2+

chef-full-old-hostname.erb

sh -c '
<%= "export https_proxy=\"#{knife_config[:bootstrap_proxy]}\"" if knife_config[:bootstrap_proxy] -%>

if test "x$TMPDIR" = "x"; then
  tmp="/tmp"
else
  tmp=$TMPDIR
fi

# secure-ish temp dir creation without having mktemp available (DDoS-able but not exploitable)
tmp_dir="$tmp/install.sh.$$"
(umask 077 && mkdir $tmp_dir) || exit 1

exists() {
  if command -v $1 >/dev/null 2>&1
  then
    return 0
  else
    return 1
  fi
}

http_404_error() {
  echo "ERROR 404: Could not retrieve a valid install.sh!"
  exit 1
}

capture_tmp_stderr() {
  # spool up /tmp/stderr from all the commands we called
  if test -f "$tmp_dir/stderr"; then
    output=`cat $tmp_dir/stderr`
    stderr_results="${stderr_results}\nSTDERR from $1:\n\n$output\n"
    rm $tmp_dir/stderr
  fi
}

# do_wget URL FILENAME
do_wget() {
  echo "trying wget..."
  wget <%= "--proxy=on " if knife_config[:bootstrap_proxy] %> <%= knife_config[:bootstrap_wget_options] %> -O "$2" "$1" 2>$tmp_dir/stderr
  rc=$?
  # check for 404
  grep "ERROR 404" $tmp_dir/stderr 2>&1 >/dev/null
  if test $? -eq 0; then
    http_404_error
  fi

  # check for bad return status or empty output
  if test $rc -ne 0 || test ! -s "$2"; then
    capture_tmp_stderr "wget"
    return 1
  fi

  return 0
}

# do_curl URL FILENAME
do_curl() {
  echo "trying curl..."
  curl -sL <%= "--proxy \"#{knife_config[:bootstrap_proxy]}\" " if knife_config[:bootstrap_proxy] %> <%= knife_config[:bootstrap_curl_options] %> -D $tmp_dir/stderr -o "$2" "$1" 2>$tmp_dir/stderr
  rc=$?
  # check for 404
  grep "404 Not Found" $tmp_dir/stderr 2>&1 >/dev/null
  if test $? -eq 0; then
    http_404_error
  fi

  # check for bad return status or empty output
  if test $rc -ne 0 || test ! -s "$2"; then
    capture_tmp_stderr "curl"
    return 1
  fi

  return 0
}

# do_fetch URL FILENAME
do_fetch() {
  echo "trying fetch..."
  fetch -o "$2" "$1" 2>$tmp_dir/stderr
  # check for bad return status
  test $? -ne 0 && return 1
  return 0
}

# do_perl URL FILENAME
do_perl() {
  echo "trying perl..."
  perl -e "use LWP::Simple; getprint(shift @ARGV);" "$1" > "$2" 2>$tmp_dir/stderr
  rc=$?
  # check for 404
  grep "404 Not Found" $tmp_dir/stderr 2>&1 >/dev/null
  if test $? -eq 0; then
    http_404_error
  fi

  # check for bad return status or empty output
  if test $rc -ne 0 || test ! -s "$2"; then
    capture_tmp_stderr "perl"
    return 1
  fi

  return 0
}

# do_python URL FILENAME
do_python() {
  echo "trying python..."
  python -c "import sys,urllib2 ; sys.stdout.write(urllib2.urlopen(sys.argv[1]).read())" "$1" > "$2" 2>$tmp_dir/stderr
  rc=$?
  # check for 404
  grep "HTTP Error 404" $tmp_dir/stderr 2>&1 >/dev/null
  if test $? -eq 0; then
    http_404_error
  fi

  # check for bad return status or empty output
  if test $rc -ne 0 || test ! -s "$2"; then
    capture_tmp_stderr "python"
    return 1
  fi
  return 0
}

# do_download URL FILENAME
do_download() {
  PATH=/opt/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sfw/bin:/sbin:/bin:/usr/sbin:/usr/bin
  export PATH

  echo "downloading $1"
  echo "  to file $2"

  # we try all of these until we get success.
  # perl, in particular may be present but LWP::Simple may not be installed

  if exists wget; then
    do_wget $1 $2 && return 0
  fi

  if exists curl; then
    do_curl $1 $2 && return 0
  fi

  if exists fetch; then
    do_fetch $1 $2 && return 0
  fi

  if exists perl; then
    do_perl $1 $2 && return 0
  fi

  if exists python; then
    do_python $1 $2 && return 0
  fi

  echo ">>>>>> wget, curl, fetch, perl, or python not found on this instance."

  if test "x$stderr_results" != "x"; then
    echo "\nDEBUG OUTPUT FOLLOWS:\n$stderr_results"
  fi

  return 16
}

<% if knife_config[:bootstrap_install_command] %>
  <%= knife_config[:bootstrap_install_command] %>
<% else %>
  install_sh="<%= knife_config[:bootstrap_url] ? knife_config[:bootstrap_url] : "https://www.opscode.com/chef/install.sh" %>"
  if test -f /usr/bin/chef-client; then
    echo "-----> Existing Chef installation detected"
  else
    echo "-----> Installing Chef Omnibus (<%= latest_current_chef_version_string %>)"
    do_download ${install_sh} $tmp_dir/install.sh
    sh $tmp_dir/install.sh -P chef <%= latest_current_chef_version_string %>
  fi
<% end %>

<%# Download custom "old hostname" ohai plugin -%>
mkdir /etc/chef/ohai/plugins -p
do_download 'https://raw.githubusercontent.com/chef/ohai/93943d36230be185b5b908b4e8937b60edbee9bb/lib/ohai/plugins/hostname.rb' /etc/chef/ohai/plugins/old_hostname.rb
sed -i s/Hostname/OldHostname/ /etc/chef/ohai/plugins/old_hostname.rb

if test "x$tmp_dir" != "x"; then
  rm -r "$tmp_dir"
fi

mkdir -p /etc/chef
<% if client_pem -%>
cat > /etc/chef/client.pem <<EOP
<%= ::File.read(::File.expand_path(client_pem)) %>
EOP
chmod 0600 /etc/chef/client.pem
<% end -%>

<% if validation_key -%>
cat > /etc/chef/validation.pem <<EOP
<%= validation_key %>
EOP
chmod 0600 /etc/chef/validation.pem
<% end -%>

<% if encrypted_data_bag_secret -%>
cat > /etc/chef/encrypted_data_bag_secret <<EOP
<%= encrypted_data_bag_secret %>
EOP
chmod 0600 /etc/chef/encrypted_data_bag_secret
<% end -%>

<% unless trusted_certs.empty? -%>
mkdir -p /etc/chef/trusted_certs
<%= trusted_certs %>
<% end -%>

<%# Generate Ohai Hints -%>
<% unless @chef_config[:knife][:hints].nil? || @chef_config[:knife][:hints].empty? -%>
mkdir -p /etc/chef/ohai/hints

<% @chef_config[:knife][:hints].each do |name, hash| -%>
cat > /etc/chef/ohai/hints/<%= name %>.json <<EOP
<%= Chef::JSONCompat.to_json(hash) %>
EOP
<% end -%>
<% end -%>

cat > /etc/chef/client.rb <<EOP
<%= config_content %>
EOP

cat > /etc/chef/first-boot.json <<EOP
<%= Chef::JSONCompat.to_json(first_boot) %>
EOP

<%# Add ohai plugin path -%>
cat >> /etc/chef/client.rb <<EOP
ohai.plugin_path << "/etc/chef/ohai/plugins"
EOP

echo "Starting the first Chef Client run..."

<%= start_chef %>'