Configure Apache and Elasticsearch

Overview of secure web server communication

This topic discusses an example of securing communication between your web server and Elasticsearch using a combination of Transport Layer Security (TLS) encryption and HTTP basic authentication. You can optionally configure other types of authentication as well; we provide references for that information.

(An older term, Secure Sockets Layer (SSL), is frequently used interchangeably with TLS. In this topic, we refer to TLS.)

Unless otherwise noted, all commands in this topic must be entered as a user with root privileges.

Recommendations

We recommend the following:

• Your web server uses TLS.

  TLS is beyond the scope of this topic; however, we strongly recommend you use a real certificate in production and not a self-signed certificate.

• Elasticsearch runs on the same host as a web server. Running Elasticsearch and the web server on different hosts is beyond the scope of this topic.

  The advantage of putting Elasticsearch and the web server on the same host is that it makes intercepting encrypted communication impossible. The Elasticsearch web server does not have to be the same as the Magento web server; for example, Magento can run Apache and Elasticsearch can run nginx. If Elasticsearch is exposed to the public web, you should configure authentication. If your Elasticsearch instance is protected within your network, this may not be necessary. Work with your hosting provider to determine which security measures you should implement to protect your instance.

More information about TLS

See one of the following resources:

• Apache

  • Apache 2.4 strong encryption how-to
  • How To Create a SSL Certificate on Apache for Ubuntu 14.04 (Digitalocean tutorial)
  • Setting up an SSL secured Webserver with CentOS (CentOS wiki)

• Nginx

  • Nginx SSL termination
  • How To Create an SSL Certificate on Nginx for Ubuntu 14.04 (Digitalocean tutorial)
  • Nginx SSL Certificate Installation (digicert)

Set up a proxy

This section discusses how to configure Apache as an unsecure proxy so that Magento can use Elasticsearch running on this server. This section does not discuss setting up HTTP Basic authentication; that is discussed in Secure communication with Apache.

The reason the proxy is not secured in this example is it’s easier to set up and verify. You can use TLS with this proxy if you want; to do so, make sure you add the proxy information to your secure virtual host configuration.

Set up a proxy for Apache 2.4

This section discusses how to configure an Elasticsearch proxy using a virtual host.

1. Enable mod_proxy as follows:

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   a2enmod proxy_http
   

2. Use a text editor to open /etc/apache2/sites-available/000-default.conf

3. Add the following directive at the top of the file:

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   Listen 8080
   

4. Add the following at the bottom of the file:

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   <VirtualHost *:8080>
       ProxyPass "/" "http://localhost:9200/"
       ProxyPassReverse "/" "http://localhost:9200/"
   </VirtualHost>
   

5. Restart Apache:

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   service apache2 restart
   

6. Verify the proxy works by entering the following command:

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   curl -i http://localhost:<proxy port>/_cluster/health
   

   For example, if your proxy uses port 8080:

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   curl -i http://localhost:8080/_cluster/health
   

   Messages similar to the following display to indicate success:

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   HTTP/1.1 200 OK
   Date: Tue, 23 Feb 2016 20:38:03 GMT
   Content-Type: application/json; charset=UTF-8
   Content-Length: 389
   Connection: keep-alive
   
   {"cluster_name":"elasticsearch","status":"yellow","timed_out":false,"number_of_nodes":1,"number_of_data_nodes":1,"active_primary_shards":5,"active_shards":5,"relocating_shards":0,"initializing_shards":0,"unassigned_shards":5,"delayed_unassigned_shards":0,"number_of_pending_tasks":0,"number_of_in_flight_fetch":0,"task_max_waiting_in_queue_millis":0,"active_shards_percent_as_number":50.0}
   

Secure communication with Apache

This section discusses how to secure communication between Apache and Elasticsearch using HTTP Basic authentication with Apache. For more options, consult one of the following resources:

• Apache 2.4 authentication and authorization tutorial

See one of the following sections:

• Step 1: Create a password file
• Step 2: Configure your secure virtual host
• Verify communication is secure

Step 1: Create a password

For security reasons, you can locate the password file anywhere except your web server docroot. In this example, we show how to store the password file in a new directory.

Install htpasswd if necessary

First, see if you have the Apache htpasswd utility is installed as follows:

1. Enter the following command to determine if htpasswd is already installed:

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   which htpasswd
   

   If a path displays, it is installed; if the command returns no output, htpasswd is not installed.

2. If necessary, install htpasswd:

   • Ubuntu: apt-get -y install apache2-utils
   • CentOS: yum -y install httpd-tools

Create a password file

Enter the following commands as a user with root privileges:

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mkdir -p /usr/local/apache/password

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htpasswd -c /usr/local/apache/password/.<password file name> <username>

where

• <username> can be:

  • Setting up cron: the web server user or another user.

    In this example, we use the web server user but the choice of user is up to you.

  • Setting up Elasticsearch: the user is named magento_elasticsearch in this example

• <password file name> must be a hidden file (starts with .) and should reflect the name of the user. See the examples later in this section for details.

Follow the prompts on your screen to create a password for the user.

Examples

Example 1: cron You must set up authentication for only one user for cron; in this example, we use the web server user. To create a password file for the web server user, enter the following commands:

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mkdir -p /usr/local/apache/password

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htpasswd -c /usr/local/apache/password/.htpasswd apache

Example 2: Elasticsearch You must set up authentication for two users: one with access to nginx and one with access to Elasticsearch. To create password files for these users, enter the following commands:

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mkdir -p /usr/local/apache/password

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htpasswd -c /usr/local/apache/password/.htpasswd_elasticsearch magento_elasticsearch

Add additional users

To add another user to your password file, enter the following command as a user with root privileges:

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htpasswd /usr/local/apache/password/.htpasswd <username>

Step 2: Secure communication with Apache

This section discusses how to set up HTTP Basic authentication. Use of TLS and HTTP Basic authentication together prevents anyone from intercepting communication with Elasticsearch or with your Magento server.

This section discusses how to specify who can access the Apache server.

1. Use a text editor to add the following contents to your secure virtual host.

   • Apache 2.4: Edit /etc/apache2/sites-available/default-ssl.conf

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   <Proxy *>
       Order deny,allow
       Allow from all
   
       AuthType Basic
       AuthName "Elastic Server"
       AuthBasicProvider file
       AuthUserFile /usr/local/apache/password/.htpasswd_elasticsearch
       Require valid-user
   
     # This allows OPTIONS-requests without authorization
     <LimitExcept OPTIONS>
           Require valid-user
     </LimitExcept>
   </Proxy>
   

2. If you added the preceding to your secure virtual host, remove Listen 8080 and the <VirtualHost *:8080> directives you added earlier to your unsecure virtual host.

3. Save your changes, exit the text editor, and restart Apache:

   • CentOS: service httpd restart
   • Ubuntu: service apache2 restart

Verify communication is secure

This section discusses two ways to verify that HTTP Basic authentication is working:

• Using a curl command to verify you must enter a username and password to get cluster status
• Configuring HTTP Basic authentication in the Magento Admin

Use a curl command to verify cluster status

Enter the following command:

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curl -i http://<hostname, ip, or localhost>:<proxy port>/_cluster/health

For example, if you enter the command on the Elasticsearch server and your proxy uses port 8080:

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curl -i http://localhost:8080/_cluster/health

The following message displays to indicate authentication failed:

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HTTP/1.1 401 Unauthorized
Date: Tue, 23 Feb 2016 20:35:29 GMT
Content-Type: text/html
Content-Length: 194
Connection: keep-alive
WWW-Authenticate: Basic realm="Restricted"

<html>
<head><title>401 Authorization Required</title></head>
<body bgcolor="white">
  <center><h1>401 Authorization Required</h1></center>

</body>
</html>

Now try the following command:

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curl -i -u <username>:<password> http://<hostname, ip, or localhost>:<proxy port>/_cluster/health

For example:

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curl -i -u magento_elasticsearch:mypassword http://localhost:8080/_cluster/health

This time the command succeeds with a message similar to the following:

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HTTP/1.1 200 OK
Date: Tue, 23 Feb 2016 20:38:03 GMT
Content-Type: application/json; charset=UTF-8
Content-Length: 389
Connection: keep-alive

{"cluster_name":"elasticsearch","status":"yellow","timed_out":false,"number_of_nodes":1,"number_of_data_nodes":1,"active_primary_shards":5,"active_shards":5,"relocating_shards":0,"initializing_shards":0,"unassigned_shards":5,"delayed_unassigned_shards":0,"number_of_pending_tasks":0,"number_of_in_flight_fetch":0,"task_max_waiting_in_queue_millis":0,"active_shards_percent_as_number":50.0}

Configure HTTP Basic authentication in the Magento Admin

Perform the same tasks as discussed in Configure Magento to use Elasticsearch except click Yes from the Enable Elasticsearch HTTP Auth list and enter your username and password in the provided fields.

Click Test Connection to make sure it works and then click Save Config.

You must flush the Magento cache and reindex before you continue.

Related topic

Configure Elasticsearch stopwords