This GitHub provides instructions to setup DocBook on Ubuntu 16.04, 18.04 and 20.04 with Apache FOP 2.9.
The instructions include the steps to install packages such as docbook, docbook-xsl, docbook-xsl-doc-pdf and xsltproc. The instructions also cover installation of the Java Runtime Environment (JRE) or Development Kit (JDK), if needed.
The instructions are in docbook-install.pdf. Once DocBook is setup just run make-book.sh to create the book.
DocBook allows you to change the style of your book by using a custom stylesheet. For example, you can change the font family, font size, paragraph indents, left margin, or right margin. Since this book's custom.xsl is created on the fly, you should make your changes to custom.xsl.in. custom.xsl.in will be used to create the custom.xsl to build the book.
The XSLT translator consumes custom.xsl like shown below. The translator creates the formatted object that Apache's FOP uses to create the PDF.
xsltproc --xinclude custom.xsl book.xml > "${BOOKNAME}.fo"
This DocBook has changes applied in custom.xsl.in. The font family and font size were changed to 11 point Arial to make the book easier on the eyes. Margins and outdents were also changed to use more of the available page.
make-book.sh builds the book on both Ubuntu and Fedora. Ubuntu and Fedora use different paths to the DocBook stylesheets, so different custom.xsl are needed. make-book.sh will create a custom.xsl using the path to the DocBook stylesheets for the site.
make-book.sh will detect the location of the stylesheets if it is not specified by the user. After the code runs, DOCBOOK_XSL will contain a location like /usr/share/xml/docbook/stylesheet/docbook-xsl/fo/docbook.xsl.
DOCBOOK_XSL="$(find /usr/share -name 'docbook.xsl' 2>/dev/null | grep -E '/fo/docbook.xsl$' | head -n 1)"
make-book.sh will then create the custom stylesheet, substituting the location for !!DOCBOOK_XSL!! in the custom style sheet.
# This magic allows us to build the DocBook on Ubuntu and Fedora.
# Ubuntu and Fedora use different paths to docbook.xsl.
sed "s|!!DOCBOOK_XSL_FILE!!|${DOCBOOK_XSL}|g" custom.xsl.in > custom.xsl
And the corresponding part of custom.xsl.in is shown below.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:import href="!!DOCBOOK_XSL_FILE!!"/>
...
</xsl:stylesheet>
The remainder of make-book.sh lints the sources, creates the formatted object, builds the book and optimizes the book.