feat: Publish EPUB format for download.

Signed-off-by: Radoslav Husar <[email protected]>

Author: rhusar

docs/pom.xml

@@ -17,6 +17,7 @@
     <properties>
         <version.asciidoctor-maven-plugin>3.2.0</version.asciidoctor-maven-plugin>
         <version.org.asciidoctor.asciidoctorj-pdf>2.3.19</version.org.asciidoctor.asciidoctorj-pdf>
+        <version.org.asciidoctor.asciidoctorj-epub3>2.2.0</version.org.asciidoctor.asciidoctorj-epub3>
     </properties>
 
     <build>
@@ -31,9 +32,14 @@
                         <artifactId>asciidoctorj-pdf</artifactId>
                         <version>${version.org.asciidoctor.asciidoctorj-pdf}</version>
                     </dependency>
+                    <dependency>
+                        <groupId>org.asciidoctor</groupId>
+                        <artifactId>asciidoctorj-epub3</artifactId>
+                        <version>2.2.0</version>
+                    </dependency>
                 </dependencies>
                 <executions>
-                    <!-- User guide html + pdf -->
+                    <!-- User guide - HTML -->
                     <execution>
                         <id>output-html-user-guide</id>
                         <phase>package</phase>
@@ -68,6 +74,7 @@
                             <enableVerbose>true</enableVerbose>
                         </configuration>
                     </execution>
+                    <!-- User guide - PDF -->
                     <execution>
                         <id>output-pdf-user-guide</id>
                         <phase>generate-resources</phase>
@@ -89,6 +96,28 @@
                             <outputFile>mod_cluster-v2-user-guide.pdf</outputFile>
                         </configuration>
                     </execution>
+                    <!-- User guide - EPUB -->
+                    <execution>
+                        <id>output-epub-user-guide</id>
+                        <phase>generate-resources</phase>
+                        <goals>
+                            <goal>process-asciidoc</goal>
+                        </goals>
+                        <configuration>
+                            <backend>epub3</backend>
+                            <resources>
+                                <resource>
+                                    <directory>src/main/asciidoc/images</directory>
+                                    <targetPath>images</targetPath>
+                                </resource>
+                            </resources>
+                            <doctype>book</doctype>
+                            <sourceDirectory>src/main/asciidoc</sourceDirectory>
+                            <sourceDocumentName>index.adoc</sourceDocumentName>
+                            <enableVerbose>true</enableVerbose>
+                            <outputFile>mod_cluster-v2-user-guide.epub</outputFile>
+                        </configuration>
+                    </execution>
                     <!-- Developer resources html (migrated from old JBoss Wiki) -->
                     <execution>
                         <id>output-html-developer-resources</id>

docs/src/main/asciidoc/introduction.adoc

@@ -1,5 +1,5 @@
 ifeval::["{backend}" == "html5"]
-TIP: This document is also available as a link:mod_cluster-v2-user-guide.pdf[PDF to download].
+TIP: This document is also available as a link:mod_cluster-v2-user-guide.pdf[PDF] and link:mod_cluster-v2-user-guide.epub[EPUB] to download.
 endif::[]
 
 [[overview]]