Home > Articles

This chapter is from the book

9.2 Jekyll

When building a professional-grade website, it’s essential to use a system capable of supporting templates to eliminate duplication. To accomplish this, we’ll be using Jekyll (https://jekyllrb.com/) (Figure 9.21), a free and open-source program for generating static websites (that is, sites that don’t change from visit to visit).2

Figure 9.2

Figure 9.2: Not Jekyll and Hyde… rather, Jekyll the static site generator! (Poster image courtesy of BFA/Alamy Stock Photo.)

By learning Jekyll, you’ll cultivate the skills needed to develop and deploy a real website—skills that are transferable to other static site generators (such as Middleman and Hugo) and to full-blown web frameworks (like Ruby on Rails (https://www.railstutorial.org/)). Learning the template language used by Jekyll (called Liquid) is also a valuable skill in itself, as Liquid is widely used in systems like the Shopify ecommerce platform.3

In addition to supporting templates, Jekyll also includes a bunch of other useful features:

  • Write content in Markdown (the lightweight markup format we first discussed in Chapter 6 of Learn Enough Developer Tools to Be Dangerous) in your text editor of choice.

  • Write and preview your content on your site locally in your dev environment.

  • Publish changes via Git (which also gives you an automatic off-site backup).

  • Host your site for free on GitHub Pages.

  • No database management.

Originally developed by GitHub cofounder Tom Preston-Werner, Jekyll is used by millions of people around the world and is an industrial-strength tool for creating static websites. For example, the fundraising platform for U.S. President Barack Obama’s 2012 reelection campaign, which handled 81,548,259 pageviews and raised over $250 million, was built using Jekyll:

  • By using Jekyll, we managed to avoid the complexity that comes with most CMSes (databases, server configuration) and instead were able to focus on things like optimizing the UI and providing a better user experience. To work in this environment, the most a front-end engineer had to learn was the Liquid template language that Jekyll uses, and boy is that simple.4

9.2.1 Installing and Running Jekyll

Jekyll is written in the Ruby programming language, and is distributed as a Ruby gem, or self-contained package of Ruby code. As a result, installing Jekyll is easy once you have a properly configured Ruby development environment.

If your system is not already configured as a dev environment, you should consult Learn Enough Dev Environment to Be Dangerous (https://www.learnenough.com/dev-environment) at this time. This step might prove challenging, especially if you decide to configure your native system, but in the long run the effort is well worth the reward.

Once you’ve got a working dev environment, you can install Jekyll using Bundler, a manager for Ruby gems. We can install Bundler using the gem command, which comes with Ruby:

$ gem install bundler -v 2.3.14

Next, we need to create a so-called Gemfile to specify the Jekyll gem:

$ touch Gemfile

Then use a text editor to fill the Gemfile with the contents shown in Listing 9.1.

Listing 9.1: Adding the Jekyll gem.

source 'https://rubygems.org'

gem 'jekyll', '4.2.2'
gem 'webrick', '1.7.0'

If you run into any trouble, check the Gemfile at https://github.com/mhartl/mhartl.github.io to see if it has been updated.

Finally, we can install the jekyll gem using bundle install (with a little extra code to ensure that we’re using the right version of Bundler):

$ bundle _2.3.14_ install

Although Jekyll is designed to work with a system of templates (Section 9.3), in fact it can work with a single file, such as our current index.html. To see how it works, we can run the Jekyll server in our project directory (using bundle exec to ensure that the right version of Jekyll gets run):

$ bundle _2.3.14_ exec jekyll serve

If you’re working on a native system or a virtual machine (as opposed to a cloud IDE), at this point the Jekyll app should be available at the URL http://localhost:4000, where localhost is the address of the local computer and 4000 is the port number (Box 9.1). The result should look something like Figure 9.3.

Figure 9.3

Figure 9.3: No more URL pointing to a file—you’re running on a server now!

If you’re using the cloud IDE (https://www.learnenough.com/dev-environment-tutorial#sec-cloud_ide) suggested in Learn Enough Dev Environment to Be Dangerous, you’ll have to pass options for the port number (Box 9.1) and host IP number when running the jekyll command:

$ bundle _2.3.14_ exec jekyll serve --port $PORT --host $IP

Here $PORT and $IP should be typed in literally; they are environment variables provided by the cloud IDE to make the development site accessible on an external URL. Once the server is running, you can visit it by selecting Share and then clicking on the server URL, as shown in Figure 9.4. The result, apart from the browser URL, should be the same as for the local system shown in Figure 9.3. (For simplicity, in what follows we sometimes refer to localhost:4000, but users of the cloud IDE should use their personal URL instead. Mutatis mutandis.)

Figure 9.4

Figure 9.4: Sharing the URL on the cloud IDE.

After starting the Jekyll server, you should find a new folder in your project called _site (with a leading underscore):

$ ls
_site      index.html

This folder contains the output from the Jekyll server as it builds your site from the source files (currently just index.html).

The _site directory and all its contents are generated by Jekyll every time a file is saved, and if you were to make any changes in the _site folder, they will be automatically overwritten. As a result, you should never make changes in any of the _site files themselves—they would only be overwritten by Jekyll. There’s nothing more frustrating than accidentally working on updates in an automatically generated folder, only to have your changes overwritten by an uncaring static site generator (Figure 9.5).5

Figure 9.5

Figure 9.5: TFW changes accidentally made in generated files get overwritten.

Because all its content is generated by Jekyll, it’s a good idea to ignore the _site directory by adding it to your .gitignore file, and there’s a Bundler configuration directory called .bundle that should also be ignored:

$ echo _site/ >> .gitignore
$ echo .bundle >> .gitignore
$ git add .gitignore
$ git commit -m "Ignore the generated site and Bundler directories"

You should also add the Gemfile (and the associated auto-generated Gemfile.lock file) to the repository:

$ git add -A
$ git commit -m "Add a Gemfile"

9.2.2 Exercises

  1. Try starting Jekyll on a non-standard port like 1234.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020