Loop through array in Chef Template (ERB)

Question

I'm new to chef and starting to learn the ropes and want to know if the below is possible and how to achieve it. I'm coming from someone who's been using ansible for the past 2 years.

I want to know how to manipulate .erb templates

ansible code - varible.yml

apache_vhosts:
  - servername: "{{ enterprise }}.test.io"
    serveralias: "{{ inventory_hostname }}"
    documentroot: "/var/www/test/current/web"
    symfony_prod: true
    redirect_https: true
  - servername: "{{ enterprise }}forms.test.io"
    documentroot: "/var/www/test/current/web"
    symfony_form: true
    redirect_https: true
  - servername: "{{ enterprise }}trk.test.io"
    documentroot: "/var/www/test/current/web"
    symfony_track: true
    redirect_https: true

ansible code - vhosts.conf.j2 (jinja template)

{% for vhost in apache_vhosts %}
<VirtualHost *:{{ apache_listen_port_http }}>
  ServerName {{ vhost.servername }}
{% if vhost.redirect_https is defined and vhost.redirect_https == true %}
  Redirect 301 / https://{{ vhost.servername }}/
  {% else %}
  DocumentRoot {{ vhost.documentroot }}
{% if vhost.serveradmin is defined %}
  ServerAdmin {{ vhost.serveradmin }}
{% endif %}

{% if vhost.symfony_dev is defined %}

  DirectoryIndex app_dev.php

  <Directory "{{ vhost.documentroot }}">
    AllowOverride None
    Options -Indexes +FollowSymLinks
    Order allow,deny
    Allow from all
    # Symfony2 rewriting rules
    RewriteEngine On
    RewriteCond %{REQUEST_FILENAME} -f
    RewriteRule .? - [L]
    RewriteRule .? %{ENV:BASE}/app_dev.php [L]
  </Directory>
{% elif vhost.symfony_prod is defined %}

  DirectoryIndex app.php

  <Directory "{{ vhost.documentroot }}">
    AllowOverride None
    Options -Indexes +FollowSymLinks
    Order allow,deny
    Allow from all
    # Symfony2 rewriting rules
    RewriteEngine On
    RewriteCond %{REQUEST_FILENAME} -f
    RewriteRule .? - [L]
    RewriteRule .? %{ENV:BASE}/app.php [L]
  </Directory>
{% else %}

  <Directory "{{ vhost.documentroot }}">
    AllowOverride All
    Options -Indexes +FollowSymLinks
    Order allow,deny
    Allow from all
  </Directory>

{% endif %}

{% if vhost.extra_parameters is defined %}
  {{ vhost.extra_parameters }}
{% endif %}

{% endif %}

</VirtualHost>

{% endfor %}

From the code above, you can see that I'm looping through apache_vhosts in the .yml file and using the inner objects as I create the template. Is this possible with .erb how do I replicate this in a .rb attributes file.

Currently I just have the below;

chef code - default.rb

# Apache attributes
default["altostack"]["apache_conf_path"] = "/etc/apache2/sites-enabled"
default["altostack"]["apache_redirect_https"] = false
default["altostack"]["apache_servername"] = "test.test.io"
default["altostack"]["apache_documentroot"] = "/var/www/test/current/web"
default["altostack"]["apache_ssl_crt_dir"] = case node.environment
when '_default'
  default["altostack"]["apache_ssl_crt_dir"] = "/etc/apache2/ssl/"
end

Answer 1

To replicate more or less your ansible format:

# Apache attributes

default["altostack"]["test.test.io"]["apache_conf_path"] = "/etc/apache2/sites-enabled"
default["altostack"]["test.test.io"]["apache_redirect_https"] = false
default["altostack"]["test.test.io"]["apache_documentroot"] = "/var/www/test/current/web"
default["altostack"]["test.test.io"]["apache_ssl_crt_dir"] = case node.environment
when '_default'
   "/etc/apache2/ssl/"
end

#Alternative synteax with hash:

default["altostack"]["test_2.test.io"]= {
  "apache_conf_path" => "/etc/apache2/sites-enabled",
  "apache_redirect_https" => false,
  "apache_documentroot" => "/var/www/test/current/web"
}

# For the case statement, better use the usual approach, easier to maitain IMHO
default["altostack"]["test_2.test.io"]["apache_ssl_crt_dir"] = case node.environment
  when '_default'
     "/etc/apache2/ssl/"
  end

In the template file:

<% node['altostack'].each do |servername,properties| -%>
  <VirtualHost *:<%= properties['apache_redirect_https'] %>
    ServerName <%= servername %>
    <% if !properties['redirect_https'].nil? and properties['redirect_https'] == true -%>
  Redirect 301 / https://<%= servername %>/
  <% else -%>
  DocumentRoot <%= properties['documentroot'] %>
<% if !properties['serveradmin'].nil? -%>
  ServerAdmin <%= properties['serveradmin'] %>
<% endif -%>
# Rest of template to be translated by yourself :)

The template syntax in chef is using erb, it is covered in the documentation here and it accept plain ruby within the template.

The usual recomendation is to take advantage of community cookbooks, here namely apache2 which has a nice Usage section in it's readme and a basic example usage of it's web_app resource.