title: spring-boot without parent pom.xml cannot generate war packaging
body: <p>I used the example gs-convert-jar-to-war provided by spring-io. It describes how to generate war packaging within a spring boot project. </p>
  
  <p>The spring-boot documentation allows for using own parent poms, thus omitting the predefined parent pom for all spring-boot projects. The following dependency has to be added:</p>
  
  <pre><code>&lt;dependencyManagement&gt;
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;!-- Import dependency management from Spring Boot --&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
              &lt;version&gt;1.0.1.RELEASE&lt;/version&gt;
              &lt;type&gt;pom&lt;/type&gt;
              &lt;scope&gt;import&lt;/scope&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  &lt;/dependencyManagement&gt;
  </code></pre>
  
  <p>I applied this change (and only this change) to the example. Afterwards it is no longer possible to generate the war. I get following error message:</p>
  
  <pre><code>[ERROR] Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.1.1:war (default-war) on project gs-convert-jar-to-war: Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode) -&gt; [Help 1]
  </code></pre>
  
  <p>Here is the complete listing of the modified pom.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;org.springframework-sample&lt;/groupId&gt;
      &lt;artifactId&gt;gs-convert-jar-to-war&lt;/artifactId&gt;
      &lt;version&gt;0.1.0&lt;/version&gt;
      &lt;packaging&gt;war&lt;/packaging&gt;
  
      &lt;dependencyManagement&gt;
          &lt;dependencies&gt;
              &lt;dependency&gt;
                  &lt;!-- Import dependency management from Spring Boot --&gt;
                  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                  &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
                  &lt;version&gt;1.0.1.RELEASE&lt;/version&gt;
                  &lt;type&gt;pom&lt;/type&gt;
                  &lt;scope&gt;import&lt;/scope&gt;
              &lt;/dependency&gt;
          &lt;/dependencies&gt;
      &lt;/dependencyManagement&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-thymeleaf&lt;/artifactId&gt;
              &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-tomcat&lt;/artifactId&gt;
              &lt;scope&gt;provided&lt;/scope&gt;
              &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
      &lt;properties&gt;
          &lt;start-class&gt;hello.Application&lt;/start-class&gt;
      &lt;/properties&gt;
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                  &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
  
      &lt;repositories&gt;
          &lt;repository&gt;
              &lt;id&gt;spring-milestones&lt;/id&gt;
              &lt;name&gt;Spring Milestones&lt;/name&gt;
              &lt;url&gt;http://repo.spring.io/libs-milestone&lt;/url&gt;
          &lt;/repository&gt;
      &lt;/repositories&gt;
  
      &lt;pluginRepositories&gt;
          &lt;pluginRepository&gt;
              &lt;id&gt;spring-milestones&lt;/id&gt;
              &lt;name&gt;Spring Milestones&lt;/name&gt;
              &lt;url&gt;http://repo.spring.io/libs-milestone&lt;/url&gt;
          &lt;/pluginRepository&gt;
      &lt;/pluginRepositories&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>Is there any idea to overcome the problem?</p>
  
  <p>In my project I will use my own parent pom, because it defines a lot of stuff regarding the company. </p>