Add a Custom Search to your Site with Solr

Apache Solr is an open source search platform that provides administrators with a customizable and scalable solution for managing online content. Solr can be configured to index all uploaded data, resulting in fast search results, whether used enterprise-wide or with a single website. In addition to a built-in web control interface, developers can also link access via a client API.

Before You Begin

1. Familiarize yourself with our Getting Started guide and complete the steps for setting your Linode’s hostname and timezone.

2. Complete the Securing Your Server to create a standard user account, harden SSH access and remove unnecessary network services.

3. Update your system and package repositories and install wget.

Install Java

1. Install Java 8 JDK:

   Debian & Ubuntu

   1. Add the Java 8 repository, download the GPG key, and install Java 8.

       echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main" | tee /etc/apt/sources.list.d/webupd8team-java.list
       echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main" | tee -a /etc/apt/sources.list.d/webupd8team-java.list
       apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
       apt update
       apt install oracle-java8-installer
      

   2. On most systems, the oracle-java8-set-default package will also be downloaded and installed. To verify, run the following command and check for matching output. If your output does not match, continue to Step 3. Otherwise, Java 8 installation is complete:

       dpkg --list | grep oracle
      

      Output:

       ii  oracle-java8-installer        8u144-1~webupd8~0            all          Oracle Java(TM) Development Kit (JDK) 8
       ii  oracle-java8-set-default      8u144-1~webupd8~0            all          Set Oracle JDK 8 as default Java
      

   3. Install the oracle-java8-set-default package:

       apt install oracle-java8-set-default
      

   Fedora & RHEL based

    yum install java-1.8.0-openjdk.x86_64
   

   Arch Linux

    pacman -S jre8-openjdk
   

   openSUSE

    zypper in java-1_8_0-openjdk
   

2. Verify the Java installation:

   java -version
   

   The output should be similar to:

   openjdk version "1.8.0_144"
   OpenJDK Runtime Environment (IcedTea 3.5.1) (suse-13.3-x86_64)
   OpenJDK 64-Bit Server VM (build 25.144-b01, mixed mode)
   

Download and Install Apache Solr

Replace each instance of 6.6.1 in the examples below with the latest version from the official Apache Solr website.

1. Navigate to the /opt directory and download Solr:

   cd /opt
   wget http://apache.claz.org/lucene/solr/6.6.1/solr-6.6.1.tgz
   

2. Extract the Solr installation script from the downloaded archive:

    tar xzf solr-6.6.1.tgz solr-6.6.1/bin/install_solr_service.sh --strip-components=2
   

3. Execute the Solr installation script. Arch Linux users should skip to the Arch-specific steps below:

    bash ./install_solr_service.sh solr-6.6.1.tgz
   

   Arch Linux

   1. Download the installation script for Arch Linux:

       wget https://github.com/Darkstar90/solr-arch-install/blob/master/install_solr_service_arch.sh
      

   2. Execute the custom Arch Linux installation script:

       bash ./install_solr_service_arch.sh solr-6.6.1.tgz
      

Create a Firewall Rule for Solr

Solr listens on port 8983 by default. Open the port to allow access to the web interface using your preferred firewall manager:

FirewallD

sudo firewall-cmd --zone=public --add-port=8983/tcp --permanent
sudo firewall-cmd --reload

UFW

ufw allow 8983/tcp comment "Solr port"

iptables

iptables -A INPUT -p tcp --dport 8983 -j ACCEPT -m comment --comment "Solr port"

Access the Solr Administration Page

Solr is managed from a web-facing administration page, which can be reached via your Linode’s IP address or domain name on port 8983.

In a web browser, enter your Linode’s IP address or domain name, followed by port 8983:

198.51.100.0:8983/solr

Secure the Solr Administration Page

Set up a password protected login page for the Solr admin page:

1. Navigate to /opt/solr/server/etc and edit the webdefault.xml file. Add the following to the end of the file, before </web-app>:

   File: /opt/solr/server/etc/webdefault.xml

   1 2 3 4 5 6 7 8 9 10 11 12 13 14

   <login-config> <auth-method>BASIC</auth-method> <realm-name>Solr Admin Auth</realm-name> </login-config> <security-constraint> <web-resource-collection> <web-resource-name>Solr Admin Auth</web-resource-name> <url-pattern>/*</url-pattern> </web-resource-collection> <auth-constraint> <role-name>user</role-name> </auth-constraint> </security-constraint>

2. In the same directory, edit the jetty.xml file and add the following before </Configure> at the end:

   File: /opt/solr/server/etc/jetty.xml

   1 2 3 4 5 6 7 8 9

   <Call name="addBean"> <Arg> <New class="org.eclipse.jetty.security.HashLoginService"> <Set name="name">Solr Admin Auth</Set> <Set name="config"><SystemProperty name="jetty.home" default="."/>/etc/realm.properties</Set> <Set name="refreshInterval">0</Set> </New> </Arg> </Call>

3. Create a realm.properties file in the current directory to add the user login information. Replace the username admin and admin123 password with the user and secure password of your choice:

   File: /opt/solr/server/etc/realm.properties

   1	admin: admin123,user

   Here, admin: assigns a username “admin” with the password admin123. user attributes this new user to the “user” role-name set in webdefault.xml.

4. Restart the solr service:

    systemctl restart solr
   

5. You can also use this process to secure other web pages within Solr. For example, if you have two Solr search cores created, core1 and core2, you can limit access to both by adding additional <url-pattern> lines to webdefault.xml:

    <url-pattern>/core1/*</url-pattern>
    <url-pattern>/core2/*</url-pattern>
   

Where to Go From Here

With Solr installed on your Linode, you are now ready to create search indexes and add data, or integrate it with your web application or website. If you need help with this, the Apache Solr Reference Guide page on the Apache Solr website is a great place to start.

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• Apache Solr Reference Guide