WAR (Servlet Container)

A WAR archive allows you to easily deploy your application inside your web container / servlet container,by just copying it to its webapps folder. Ktor supports two popular servlet containers: Jetty and Tomcat.It also serves when deploying to google app engine.

To generate a war file, you can use the gretty gradle plugin. You also need a WEB-INF/web.xml which looks like this:

webapp/WEB-INF/web.xml

  1. <?xml version="1.0" encoding="ISO-8859-1" ?>
  3. <web-app xmlns="http://java.sun.com/xml/ns/javaee"
  4.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  5.          xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
  6.          version="3.0">
  7.     <!-- path to application.conf file, required -->
  8.     <!-- note that this file is always loaded as an absolute path from the classpath -->
  9.     <context-param>
  10.         <param-name>io.ktor.ktor.config</param-name>
  11.         <param-value>application.conf</param-value>
  12.     </context-param>
  14.     <servlet>
  15.         <display-name>KtorServlet</display-name>
  16.         <servlet-name>KtorServlet</servlet-name>
  17.         <servlet-class>io.ktor.server.servlet.ServletApplicationEngine</servlet-class>
  19.         <!-- required! -->
  20.         <async-supported>true</async-supported>
  22.         <!-- 100mb max file upload, optional -->
  23.         <multipart-config>
  24.             <max-file-size>304857600</max-file-size>
  25.             <max-request-size>304857600</max-request-size>
  26.             <file-size-threshold>0</file-size-threshold>
  27.         </multipart-config>
  28.     </servlet>
  30.     <servlet-mapping>
  31.         <servlet-name>KtorServlet</servlet-name>
  32.         <url-pattern>/</url-pattern>
  33.     </servlet-mapping>
  35. </web-app>

build.gradle

  1. buildscript {
  2.     ext.gretty_version = '2.0.0'
  4.     repositories {
  5.         jcenter()
  6.     }
  7.     dependencies {
  8.         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
  9.         classpath "org.akhikhl.gretty:gretty:$gretty_version"
  10.     }
  11. }
  13. apply plugin: 'kotlin'
  14. apply plugin: 'war'
  15. apply plugin: 'org.akhikhl.gretty'
  17. webAppDirName = 'webapp'
  19. gretty {
  20.     contextPath = '/'
  21.     logbackConfigFile = 'resources/logback.xml'
  22. }
  24. sourceSets {
  25.     main.kotlin.srcDirs = [ 'src' ]
  26.     main.resources.srcDirs = [ 'resources' ]
  27. }
  29. repositories {
  30.     jcenter()
  31. }
  33. dependencies {
  34.     compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
  35.     compile "io.ktor:ktor-server-servlet:$ktor_version"
  36.     compile "io.ktor:ktor-html-builder:$ktor_version"
  37.     compile "ch.qos.logback:logback-classic:$logback_version"
  38. }
  40. kotlin.experimental.coroutines = 'enable'
  42. task run
  44. afterEvaluate {
  45.     run.dependsOn(tasks.findByName("appRun"))
  46. }

This gradle buildscript defines several tasks thatyou can use to run your application.

In the case where you only need to generate a war file, there is a war task defined in the war plugin.Just run ./gradlew war and it will generate a /build/libs/projectname.war file.

For a full example: https://github.com/ktorio/ktor-samples/tree/master/deployment/jetty-war